RSS Feed for the unit ICTs: Information

Introduction

The Open University — Mon, 18 Jul 2011 08:33:16 GMT

This unit is from our archive and it is an adapted extract from Networked living: exploring information and communication technologies (T175) which is no longer in presentation. If you wish to study formally at The Open University, you may wish to explore the courses we offer in this curriculum area.

This unit looks at the technologies used to acquire information about the world. A particular focus is the technology used by television businesses in gathering news reports. The unit draws upon the expertise of two individuals who have worked in senior positions in the UK television industry.

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Learning outcomes

The Open University — Mon, 18 Jul 2011 08:33:16 GMT

This is what you should have achieved when you have completed your study of this unit:

have a general knowledge of the different types of storage media for digital data;
understand the basic concepts of electrical voltage and resistance, and the parameters used to specify batteries;
have an overview of the historical development of ICT in video recording, newsgathering and new dissemination;
compare the merits of different media as sources of news;
discuss issues of trust and authenticity in information sources;
recognise the 'formula triangle' in a range of contexts and rearrange it to get any of the three variables in terms of the other two;
do calculations in the context of ICT systems and components, including:
speeds, propagation times and distance;
voltage, resistance and current;
the running time, current and capacity of batteries.

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1 Bringing the news on the back of a horse

The Open University — Mon, 18 Jul 2011 08:33:16 GMT

We seem to be surrounded by ‘news’ these days, but it was not always like that. In Shakespeare's Henry IV Part 2, Falstaff hears the news that his former friend and drinking partner, Prince Hal, is now King Henry V, following the death of Henry IV. It is a comic scene set in Gloucestershire, 200 km from the royal court in London, and it is clear that before the messenger (called Pistol) arrived on horseback Falstaff did not even know that Henry IV had died.

It would not be like that now. Maybe Falstaff would have got a text message on his mobile phone: Hnry 4 ded. Hal 2 b Kng Hnry 5.

And perhaps he would have then dashed home to watch BBC News 24, listen to BBC Radio Five Live or log on to the official website of the British Monarchy.

I do not want to dwell for long on the times before the Industrial Revolution, but before we move on I would like to draw out some of the themes, issues and concepts that help to provide a framework for discussing newsgathering and dissemination of news.

Activity 1

Think for a moment about the following aspects of news dissemination during the time of Henry IV and V (15th century), or any time before the Industrial Revolution.

What determined how fast the news could get from one place to another?
What determined how much information you could get about an event?
What determined how many people could find out about an event?
How far could news travel?

Discussion

For the most part, news would have travelled with people, so the answer to all of the questions about the spread of news is linked with individuals travelling. There were a few other methods that didn't require people to travel, such as beacons, semaphore and carrier pigeons, but these had rather specialised applications.

The fastest means of transport on land would have been a galloping horse, so we can think of news travelling at up to a few tens of kilometres an hour.
If a messenger is bringing the news, then perhaps the amount of information they can carry is determined by how good their memory is. They might also, or instead, have something in writing (exploiting technology) and the text could supplement their memory. Either way, a messenger can bring quite a lot of information.
If the spread of news is relying on word of mouth, then we can imagine news spreading in the way of the ‘office grapevine’ today, where one person tells two or three others who each tell another two or three people and so on. The total number of people who know the news rises rapidly in this way. Alternatively, if the news is written down, the written text can be passed around and read by more than one person (assuming widespread literacy). Even better, once printing has been invented, large numbers of copies can be produced and many people can read it at the same time.
In principle there is no limit to how far news can travel – it just might take a long time, since the speed at which it travels is limited to that of a galloping horse. In practice, only the most important news items are likely to get very far.

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2.1 Communication technologies

The Open University — Mon, 18 Jul 2011 08:33:16 GMT

With the Industrial Revolution the idea of ‘news’ developed rapidly, and these days most people in the UK and other developed countries have concept of ‘the news’. We expect to be kept up to date with the news through various sources, and to satisfy this expectation we have the businesses of newsgathering and dissemination of news.

In this section you will be learning about the development of the technologies used for newsgathering and dissemination by reading extracts from a paper written by one of the leading experts in the field.

In 1995 the IEE (Institution of Electrical Engineers – a UK-based association) held a colloquium entitled Capturing the Action: Changes in Newsgathering, which brought together technical experts working in the business of newsgathering in order to review developments. (A colloquium is a meeting at which specialists give talks on a topic or on related topics and then lead a discussion about them.) The introductory talk at the colloquium was presented by E.V. Taylor, who was at that time Head of Technology at ITN. His talk, ‘From newsreels to real news’, reviewed developments in news technology from the Industrial Revolution to 1995. As is usual with a colloquium, a ‘Colloquium Digest’ was produced which contained technical papers associated with each of the talks. I shall be using Taylor's paper to look at the role of information and communication technology (ICT) in the news business.

There are two factors which you should bear in mind as you read the paper.

The audience was made up of people working in the field or with specific interest in newsgathering. Taylor was able to assume, therefore, that his audience was already familiar with many of the concepts and the specialist language (‘jargon’) that he used.
Although the colloquium digest is available as an IEE publication, its primary distribution was to delegates who attended the colloquium (it would have been given to them when they arrived on the day). It would be used as a reminder of the talk and to fill in some of the factual details that the audience might have missed. It was not produced as a stand-alone document in the form you would find in a journal. There are no section headings, for example, and it is written using language similar to the language Taylor would have used when speaking.

Despite these shortcomings as a stand-alone printed text, Taylor's paper provides an excellent overview of the role of technology in the broadcast news industry, written by an expert who was living through the changes that were taking place. In the text which follows, I have broken down the original paper into a few paragraphs at a time and removed some text not needed for my purposes. I have also added a commentary to explain some of the terms and to discuss some other important topics in ICT.

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2.2 The role of technology in the broadcast news industry

The Open University — Mon, 18 Jul 2011 08:33:16 GMT

Taylor's introductory comments

Taylor starts with some introductory comments. Notice the informal style he uses because this is essentially a script for a talk to a colloquium. Notice also the other issue that I raised earlier, that Taylor is assuming that his listeners are familiar with terms such as ITN, ENG and video servers. I shall explain terms like these as we go through the paper. I have highlighted in bold terms which I explain or discuss further in following notes.

From Newsreels To Real News

E.V. Taylor, 1995, Institution of Electrical Engineers

Prompted partly by the fact that ITN has just celebrated its 40th anniversary I would like to start by briefly reviewing some of the historical landmarks in news broadcasting that were driven by past technological development.

With this review as a reference I hope I can convince you of the enormous importance of the new technological developments you will hear about today. Make no mistake; for the TV news business these developments are going to create a revolution even greater than that caused by ENG in the late 70s/early 80s – and those of us who lived through that particular revolution still bear some of the scars. So when, very shortly, we have to face the realities of video servers, digital compression and digital tapeless integrated newsrooms – make sure your seat belt is pulled nice and tight! We will all need to keep our nerve as I suspect it will be a bumpy ride.

(Taylor, 1995)

ITN stands for Independent Television News. To quote from the ITN website (ITN, 2005), ‘ITN is one of the largest news organisations in the world, producing news and factual programmes for television, radio and new media platforms, both in Britain and overseas. ITN was founded in 1955, as an independent organisation owned by ITV companies producing news programmes for national broadcast on ITV.’

ENG is an abbreviation of Electronic News Gathering. It is the process of recording sound and images electronically, originally as analogue signals on magnetic tapes (video and audio tapes), and conveying them back to the newsrooms in an electronic format; this could be done by physically transporting the tapes or sending the electronic signals over communications network. ENG is here contrasted with the previous use of film.

Video servers, digital compression and digital tapeless integrated newsrooms. Video servers are computers with large storage capacity (large hard disks or sets of hard disks) used to store and retrieve compressed digital video files. News editors in the ‘digital tapeless newsroom’ will be working on computers that interface with the server.

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2.3 Newsgathering and newspapers

The Open University — Mon, 18 Jul 2011 08:33:16 GMT

Newspapers

Taylor now discusses some early information and communication technologies and the extent to which they had an impact upon newspapers.

So let me start by looking at what was often optimistically called ‘news’ in the early years of the 20th Century.

Before the establishment of regular radio services in the early 1920s the public were entirely reliant upon the newspaper industry for information about what was going on locally, nationally and internationally.

Despite the development of the telegraph by William Cooke in 1837, and later the telephone by Alexander Graham Bell in 1876, it was really not until the 20th Century that lines infrastructures were developed sufficiently for newspapers to be in a position to report the remoter national events in the same week that they occurred. Reporting of events abroad was often many weeks or even months behind the occurrence. Photography had been invented in the 1830s but even by the 1900s newspaper photographs were a rarity and stories were frequently illustrated by sketches, diagrams and cartoons (interesting to note that in the UK at least artists' sketches are still the way we illustrate what is happening within a courtroom where cameras are prohibited). Newspaper photographs did exist of course but had to be hand carried back to the newspaper offices by train, ship or road – a time consuming business in those days.

This situation improved dramatically for the newspaper industry by the development of the wire picture by Reuters in the early part of this century. It is worth noting that the Reuters system was a very early example of digital coding and even incorporated data compression with a form of what we now call ‘run length coding’ – not much is really new, is it? This development enabled pictures to accompany the telegraphed or telephoned reports from many major cities in Europe and the US.

As a consequence, the newspapers prospered and fortunes were made by the now infamous press barons whose influence on both the public and governments was considerable.

(Taylor, 1995)

The lines infrastructure refers to the network of wires connecting different places together (‘line’ as in ‘telephone line’ or ‘transmission line’).

The idea of a wire picture is that an image is coded in a method that allows it to be transmitted over ‘a wire’ – i.e. sent along a telegraph link.

Taylor highlights the development of the lines infrastructure and invention of the wire picture as being developments that enabled telephony and telegraphy to be exploited by the news industry.

These are two themes you will find coming up all the time in discussions of ICT systems: networking issues – specifically ‘network reach’ – and coding

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2.4 Comparing early sources of news

The Open University — Mon, 18 Jul 2011 08:33:16 GMT

Radio and newsreels

Taylor compares the merits of radio and newsreels, as sources of news, with those of newspapers.

The value of radio as a communications medium had proved itself during the 1914–18 conflict following its development around the turn of the century by Marconi, Hertz, Popov and others.

The passing of the First World War soon saw the establishment of many national radio broadcasting organisations, the BBC being formed in 1922.

It was not long before regular news bulletins were being broadcast and despite the development of the technique of going over live to quote ‘our reporter on the spot’, which considerably enhanced the impact of the report, radio was of course not able to illustrate the news

Despite some imaginative painting of pictures with words, the newspaper industry did not regard radio as a threat but more as a useful advertising medium to alert the public to the fact that something interesting or dramatic had happened causing them to dash out to buy a newspaper to get the details and all important pictures to fill in the gaps in the radio report.

During the 1930s the ability to add live action sound onto film caused the cinema industry to explode onto the mass entertainment scene. The visual power of cinema as a news medium was quickly recognised and organisations such as British Movietone News and Pathe News soon established themselves with ‘newsreels’ which were a compilation of the week's best visual stories shot and made on high quality 35 mm film.

Despite the likelihood of the cinema goers already being aware of the newsreel stories, it was the combination of well-shot pictures with well-written, punch commentaries which made these newsreels very popular, especially during the Second World War where the visual impact was sometimes quite shocking with audiences unused to the realities of life frequently reduced to tears.

So it had taken around 100 years to develop a means and organisation from the original enabling telegraphic and photographics technologies to deliver moving news images to the public albeit somewhat later than the actual event.

In the meantime, the newspapers continued to be the primary source of news for the public.

(Taylor, 1995)

I was struck here by Taylor's comment that the public would ‘dash out to buy a newspaper to get the details and all-important pictures to fill in the gaps in the radio report’, because I will still buy a newspaper to get more details about a topic – even if I've seen pictures on TV. This raises the question of how much information you can get from different media (I believe I get more from the newspaper than from a TV report). There are also perhaps differences in the nature of the information that you can get from different media, with more comment and analysis in newspapers.

‘[T]he ability to add live action sound onto film’ mentioned by Taylor is significant because there was no sound on early film (as in ‘silent movies’), and mechanisms for recording sound onto film alongside the images came later (in the 1930s). The methods used were analogue.

The reference to 35 mm refers to the width of the film. The wider a film, the bigger the picture and the higher the quality of the projected image. However , as Taylor discusses later in the paper , the equipment needed for filming in a narrower width (16 mm was used) was lighter and more portable.

Activity 2

From your reading of this material and your understanding of the media, list the merits and limitations of each of: newspaper, radio and newsreels, as a source of news during the 1920s and 1930s. How does today's television news compare?

Discussion

Newspaper. Merits: (still) pictures, details of news stories, and you can choose when and at what pace to read. Limitations: delay (not live), no moving images, no sound.

Radio. Merits: live reports, sound. Limitations: no images.

Newsreels. Merits: moving images, sound. Limitations: delay (not live).

Today's television has the merits of radio and newsreels – live reports with sound and moving images – but often not as much depth and analysis as you can get in newspapers, nor does it have the time flexibility of newspapers.

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2.5 News and television

The Open University — Mon, 18 Jul 2011 08:33:16 GMT

Early television

In the next part of the paper Taylor discusses the early days of television.

This status quo of print/radio/cinema newsreels existed until the early 1950s when the BBC restarted TV services […].

It was natural that news bulletins would form part of this reborn visual communications medium. But resources were in short supply and early BBC TV news programmes were little more than radio news read into camera by a newsreader with a posh voice wearing a dinner jacket. What picture they did have was like the cinema newsreels shot on 35 mm film.

There was nothing there to threaten the newspaper proprietors.

But in 1955 came Commercial Television and the creation of Independent Television News.

From the start, ITN wanted to produce a newscast which would be different from the BBC's by showing much more moving picture.

Here technology came to the aid of ITN. Recent improvements had been made to the quality of film stock and ITN took the then controversial decision to adopt 16 mm film.

Compared with 35 mm equipment, the 16 mm camera was very light, more manageable and much more affordable to purchase and operate. It was therefore more suitable for volume newsgathering.

ITN judged, quite correctly as it turned out, that illustrating more stories with moving pictures would appeal to the public – even if the picture quality was somewhat worse than they were used to in the cinema or on the BBC.

The BBC soon followed with its own 16 mm equipped film crews.

[…]

By the end of the 1960s, with the introduction of colour, bulletins were taking on a style not too far removed from present day news bulletins – remember the first broadcast of News At Ten, the first half-hour news on British TV, which was in 1967.

Something else happened in the latter half of the 1960s which was to have a major impact on the immediacy of TV news – the development of the communications satellite.

Telstar in 1962 had shown the way ahead and was rapidly followed by the geostationary Early Bird satellites over the Atlantic Ocean.

TV news companies were now able to include live reports from the USA in their news bulletins.

By the early 1970s the satellite networks had become global and TV news companies were regularly including illustrated stories from around the world into their evening news programmes despite the very high price tag of $2,000 for a 10 minute slot.

The newspaper industry was now beginning to worry – television news was able to include stories in late evening bulletins which the dailies did not have for their next day editions.

(Taylor, 1995)

Restarted TV … reborn. The BBC started a TV service in 1936, but it was suspended at the outbreak of the Second World War in 1939. It was restarted after the end of the war.

The then controversial decision to adopt 16 mm film. Taylor here explains how the lower quality of 16 mm film compared with 35 mm film was more than offset by other advantages of using the smaller format.

There are parallels here in other ICT contexts, where the balance between quality and ‘being able to do it at all’ leans towards the ‘being able to do it’. For example, people seem to be willing to accept inferior sound quality from mobile telephones compared with fixed-line phones.

To put it another way, ‘good enough’ wins over ‘the best’, and in general, digital techniques allow you to make trade-offs so that the quality is pitched at ‘good enough’ for any given service. In digital audio broadcasting (DAB, digital radio) a trade-off is possible between the number of channels available and the sound quality. Currently, DAB uses a much lower quality than possible to allow for a large number of channels.

Communications satellites. Orbit the Earth and allow communications by microwave links between terrestrial locations that are a long way apart (Figure 1). They can be used for communications between fixed locations on the Earth or else to provide a wide coverage for mobile users. The original use was only for fixed locations, because the ground stations (the transmitting and receiving aerials and associated equipment on the Earth) needed for the users on the Earth were too large to be mobile.

Figure 1 Communications satellite

Satellites have to be orbiting in order to stay at a fixed height above the Earth, and the speed at which they orbit is related to their height. The higher they are, the longer they take to go once around the Earth. At one particular height – about 36,000 km above the ground – the orbit time is 24 hours. If a satellite's orbit is a ring directly above the equator at this height, the satellite will remain over the same spot on Earth. Such an orbit is known as a geostationary orbit, and a satellite in a geostationary orbit is called a geostationary satellite.

Telstar I was the first communications satellite that allowed television signals to be sent across the Atlantic, in 1962. Telstar I was not in geostationary orbit and as a consequence was only in the right position to allow transatlantic communications for 30 minutes at a time, three or four times a day.

Activity 3

What are the advantages of using 16 mm film that offset its poorer quality compared with 35 mm?

Discussion

From what Taylor says, it seems that the equipment needed for the 16 mm film was cheaper, lighter and more manageable than that needed for the 35 mm. Using 16 mm film therefore allowed ITN to have moving pictures with more of their stories.

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2.6 New media

The Open University — Mon, 18 Jul 2011 08:33:16 GMT

From film to videotape

Taylor now describes the era when film was replaced with analogue electrical video.

However, despite all these electronic advances, our newsgathering was still all film based – but the next development was not too far away.

In 1976 RCA demonstrated the […] ‘Hawkeye’ combined camera and recorder as an all electronic concept to replace newsfilm.

This development sparked the imagination of news broadcasters who quickly recognised the benefits of getting away from film with all its processing delays and bulky, expensive telecine equipment and of course its inability to provide live coverage.

By 1979 the ENG revolution was gathering momentum and it soon became unstoppable.

In 1980 ITN became the first UK broadcaster to introduce large scale ENG operations. By 1982 film as a newsgathering medium was dead.

TV news was now moving into the position of being the public's primary source of news, with newspapers accepting that they had lost the battle.

It had taken TV news just 30 years from its inception to reach this dominant position. The news reels of the 1930s, 1940s and 1950s were long gone and the demand for real up to the minute news was growing even stronger

Well, there were still large areas of the world which did not have wideband cable infrastructure or possess large expensive satellite ground stations and these became the next technological battleground.

These communication dead spots provided the challenge to fire the development of transportable ground stations.

In 1985 ITN formed an alliance with the IBA and McMichael Electronics to develop the world's first SNG uplinks – the Newshawk – which we first used in 1986.

[…]

(Taylor, 1995)

RCA (which originally stood for Radio Corporation of America) is the company that manufactured the equipment it called ‘Hawkeye’, which was one of the first examples of what we now call a ‘camcorder’ – combined video camera and recorder.

A telecine is a device that converts a film to an electrical video format. When film was used for TV newsgathering, a telecine was then needed to convert from the film to an electrical format for TV broadcast.

A wideband cable is a cable capable of conveying a wide bandwidth signal. For digital signals, that would mean a high data rate – lots of bits per second. However, here Taylor is talking about an analogue signal and he means a cable capable of carrying a wide range of frequencies. In both cases – analogue and digital – a wideband cable is the sort of cable needed to carry video signals and high-quality audio. It is in contrast to narrowband, which would be capable only of carrying less demanding signals, such as telephone-quality audio.

As noted earlier, at first satellite communications could be used only for communication between fixed locations on the Earth, but with further advances in technology, satellite ground stations could be mobile. Initially they could be mounted on a vehicle, but now they can even be small enough to be carried. Satellites allow communication to remote regions of the Earth where the infrastructure does not exist for any other means of communication (communications dead spots, as Taylor refers to them), which allowed for satellite newsgathering (SNG). The (satellite) uplink is the communication path from the ground to the satellite. The other direction is the downlink.

The IBA is the Independent Broadcasting Authority. This was the body set up to regulate commercial television and radio. It became the ITC (Independent Television Commission) in 1990, which in turn ceased to exist in December 2003 when its function was taken over by OFCOM, the Office of Communications.

The Newshawk is a portable satellite ground station, which can be connected to a video camera, used for satellite newsgathering.

Activity 4

What does Taylor say are the disadvantages of film which were overcome by moving to analogue electronic video gathered using the Hawkeye?

Discussion

Taylor says of the development of the Hawkeye camcorder:

This development sparked the imagination of news broadcasters who quickly recognised the benefits of getting away from film with all its processing delays and bulky, expensive telecine equipment and of course its inability to provide live coverage.
Taylor (1995)

In other words, the disadvantages of film were that:

there were processing delays
the equipment needed to convert from film to electronic video for broadcasting (the telecine equipment) was expensive and bulky
it could not be used for live coverage.

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2.7 Digitisation of the news

The Open University — Mon, 18 Jul 2011 08:33:16 GMT

Into the digital era

Remember that this paper was written in 1995, at which time digital techniques were just beginning to take over in electronic newsgathering. Taylor therefore concludes his paper with comments on the nature and impact of changing to digital techniques.

By the mid-1990s therefore one could be forgiven for thinking that news providers had all the technology they needed to deliver real news from more or less anywhere in the world.

And indeed we have.

So what is it that now attracts news companies to an all digital solution for newsgathering, post production and transmission?

Well, the traditional broadcast industry view is of course well known: digital brings consistent high quality pictures and sound from reliable, stable equipment which requires minimal or in some cases zero routine alignment.

Digital techniques together with advances in VLSI and [other developments in electronics], have opened the way for video signal processing to be carried out on economically priced standard computer platforms, with appropriate software, to give broadcasters much greater choice and ever more function per pound spent – great news when wrestling with hard-pressed capital budgets.

These benefits are attractive to news companies too, but the real bonus which drives our interest is the potential for digital computer based solutions to deliver high quality news programmes free from the multigeneration limitations of analogue VTRs and the editorial inflexibility of tape based production where stories cannot easily be altered or updated and at the same time achieve substantial operational cost savings.

[…]

[L]et me conclude by highlighting what I believe to be the digital newsgathering promise:

More efficient newsgathering.
More options for getting the story back.
Faster post production.
Greater editorial freedom.
Broad multiskilling opportunities.
Easier automation.
Improved technical quality.
Lower operating costs.

I make no excuse for emphasising the cost saving elements that digital news operations should achieve.

News companies are having to compete in an ever more cost conscious broadcasting industry. Our greatest asset is our staff but regrettably it is also our most expensive cost.

Yes, all the quality and other operational benefits of this technology are highly desirable and contribute toward a news provider's competitive edge, but at the end of the day it is the potential cost savings primarily achieved through multiskilling and job elimination which are the main attraction to news providers.

It is for this reason that I stated at the start of my presentation that the impact of this particular technology revolution is going to be bigger than anything we have experienced in the past.

[…]

(Taylor, 1995)

Alignment. Analogue electronic equipment often requires adjustments in order for it to perform at its best. On magnetic tapes, for example, it might be necessary to adjust the position of the record and playback heads on the tape, and the record and playback levels might have to be adjusted up or down. Generally speaking, it is much easier to make digital systems independent of alignments. This is because the exact details of the symbol do not matter, provided you can tell whether a symbol is representing a 1 or a 0.

VLSI is very-large-scale integration. Originally, electronic circuits were built from ‘discrete components’ (such as resistors, capacitors, inductors and transistors – but you do not need to know what these all are). A single component would do one job, and a complicated electronic circuit would be built up from many components. Later, integrated circuits (ICs) came along, which combined many components on a single ‘silicon chip’. As the technology advanced, more and more components could be fitted onto a single integrated circuit so that the single device (single chip) could do more and more advanced functions. Integrating large numbers of components onto a single chip was called ‘large-scale integration’, then getting even more onto a chip was ‘very-large-scale integration’. I am not sure if anyone has precisely defined ‘large’ and ‘very large’ in this context.

Video signal processing. When you have an image encoded electronically (the video signal), you can manipulate it to do things like change colours or remove unnecessary detail. Manipulating a signal in this way, for whatever purpose, is known as signal processing.

Multigenerational limitations. Each time a copy is made from an analogue signal – video or audio – there is inevitably a degradation in quality, because copying can never be perfect. Thus, there is a limit to the number of ‘generations’ of copies that can be made. The maximum number of generations before the quality becomes unacceptable depends upon the copying process and the application, but typically we are talking in terms of three or four. With digital signals this effect can be virtually eliminated, because digital signals can be regenerated and then they are ‘as good as new’.

VTR stands for video tape recorder.

Stories cannot easily be altered. As I shall be discussing later, the fact that stories can be easily altered with digital systems is not always beneficial!

The term post production refers to the collection of processes that are done to a sequence of video or audio after the filming or recording. The processes include editing and signal processing.

Activity 5

Taylor's paper highlights a number of important dates in the development of newsgathering and news broadcasts. A good way of getting a picture of historical developments is to plot events on a time line. Figure 2a begins this for some of the events mentioned by Taylor. Go back over Taylor's paper and extract more dates to add to a copy of the time line. (I found another eleven events to add.) Note that the use of ‘c’, an abbreviation for ‘circa’ meaning ‘about’, indicates an approximate date, as in c.1970 for ‘about 1970’.

View larger image

Figure 2a Start of a time line for Activity 5

Discussion

My answer is shown in Figure 2b.

View larger image

Figure 2b Time line for the answer to Activity 5

Activity 6

When considering the relationship between technology and society it is often helpful to consider influences in two directions:

Technology push. Newly developed technology creates a need that wasn't there before.
Demand (or market) pull. Users have a need, and technology is deliberately developed to satisfy that need.

Thinking in terms of the user as the news industry (journalists, and newspaper, radio or TV businesses in general), there is evidence of both technology push and demand pull in Taylor's description.

Identify one example of each, and support your answer with quotes from Taylor's paper.

Discussion

The example which I thought indicated technology push was the use of cinema for newsreels:

The visual power of cinema as a news medium was quickly recognised and organisations such as British Movietone News and Pathe News soon established themselves with ‘newsreels’ which were a compilation of the week's best visual stories shot and made on high-quality 35 mm film.
Taylor (1995)

I thought that the clearest example of demand pull was the development of the Newshawk for satellite newsgathering:

Well, there were still large areas of the world which did not have wideband cable infrastructure or possess large expensive satellite ground stations and these became the next technological battleground.
These communication dead spots provided the challenge to fire the development of transportable ground stations.
In 1985 ITN formed an alliance with the IBA and McMichael Electronics to develop the world's first SNG uplinks – the Newshawk – which we first used in 1986.
Taylor (1995)

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3.1 Introduction to SNG and ENG microwave

The Open University — Mon, 18 Jul 2011 08:33:16 GMT

Taylor's paper, From Newsreels To Real News, provided a historical overview of newsgathering up to the time the paper was written in 1995. It provides a good background but is out of date as I write this in 2005 (ten years is a very long time in the recent history of ICT). Taylor wrote an updating paper, Real News Meets IT. I shall be drawing on Real News Meets IT in later sections of this unit. In this section, I have reproduced an extract from a book (Higgins, 2004) which introduces the principal elements used by a TV station to get a report for broadcast.

Higgins says that his book was written to offer ‘beginning professionals in satellite and electronic newsgathering an introduction to the technologies and processes involved in covering an event’. Like Taylor, Higgins worked in the news industry for many years and so has the authority of an ‘insider’.

The extract here is from the beginning of the book and you should be able to follow most of the content from what you already know. As you read, try to make links with the issues raised in Taylor's paper as well as your developing understanding of ICT generally. I also found it helpful to think about news reports that I have seen on television to set the paper into a context that I could recognise.

Introduction to SNG and ENG Microwave

J. Higgins, 2004, Elsevier Focal Press

Basic Overview of the Role of ENG/SNG

Television newsgathering is the process by which materials, i.e. pictures and sound, that help tell a story about a particular event are acquired and sent back to the studio. On arrival, they may be either relayed directly live to the viewer, or edited (packaged) for later transmission.

The process of newsgathering is a complex one, typically involving cameraman and a reporter, a means of delivering the story back to the studio, and for live coverage, voice communication from the studio back to the reporter at the scene of the story.

Coverage of a sports event involves essentially the same elements but on a much greater scale. Instead of a single reporter you would have a number of commentators, and instead of a single cameraman, you might have up to thirty or forty cameras covering a major international golf tournament.

Whether it is a news or a sports event, the pictures and sound have to be sent back. This could be done by simply recording the coverage onto tape, and then taking it back to the studio. However, because of the need for immediacy, it is far more usual to send the coverage back by using a satellite or terrestrial microwave link, or via a fibre optic connection provided by, say the telephone company.

[As I shall discuss in a later section in this unit, tape is likely to be replaced by other storage media over the next few years. The story described here would be essentially the same, though, using, say, flash memory.]

[…]

Principal Element in Covering an Event

Let us just look at the principal elements of covering a news story from where it happens on location to its transmission from the TV studio.

We will pick a type of story that is of local and possibly national interest. Just suppose the story is the shooting of a police officer during a car chase following an armed robbery.

Camera and sound

The shooting happened around 2.30 pm, and the TV station newsroom was tipped off shortly after by a phone call from a member of the public at the scene.

Having checked the truth of the story with the police press office, by 3.00 pm the newsroom at the TV station despatched a cameraman (generically applied to both male and female camera operators) and a reporter to the location.

Generally these days, the cameraman is responsible for both shooting the pictures and recording the sound. The reporter finds out all the information on the circumstances of the armed robbery, the car chase and the shooting of the police officer. The cameraman may be shooting ‘GVs’ – general views of the scene and its surroundings onto tape – or interviews between the reporter, police spokesmen and eyewitnesses.

The reporter then will typically record a piece-to-camera (PTC) … which is where the reporter stands at a strategic point against a background which sets the scene for the story – perhaps the location where the officer was shot, the police station, or the hospital where the officer has been taken – and recounts the events, speaking and looking directly into the camera.

So by 5.00 pm the cameraman has several tapes (termed ‘rushes’), showing the scene, interviews and the reporter's PTC. Now, will this material be edited on site to present the story, or will the rushes be sent directly back to the station to be edited ready for the studio to use in the 6.00 pm bulletin?

Editing

The ‘cutting together’ of the pictures and sound to form a ‘cut-piece’ or ‘package’ used to be carried out mostly back at the studio.

Mobile edit vehicles were usually only deployed on the ‘big stories’, or where there was editorial pressure to produce a cut-piece actually in the field. In the latter part of the 1990s, with the increasing use of the compact digital tape formats, the major manufacturers introduced laptop editors.

The laptop editor has both a tape player and a recorder integrated into one unit, with two small TV screens and a control panel. These units, which are slightly larger and heavier than a laptop computer, can be used either by picture editor, or more commonly nowadays, by the cameraman.

During the 1990s, the pressure on TV organisations to reduce costs led to the introduction of multi-skilling, where technicians, operators and journalists are trained in at least one (and often two) other crafts apart from their primary core skill.

However, the production of a news story is rarely a contiguous serial process – more commonly, several tasks need to be carried out in parallel. For instance, the main package may need to be begun to be edited while the cameraman has to go off and shoot some extra material.

The combination of skills can be quite intriguing, so we can have a cameraman who can record sound and edit tape; a reporter who can also edit tape and/or shoot video and record sound (often referred to as a video journalist or VJ); or a microwave technician who can operate a camera and edit.

So it is often a juggling act to make sure that the right number of people with the right combination of skills available are on location all at the same time.

Getting the story back

There are now three options as to how we get the story back to the studio for transmission on the 6 o'clock news bulletin – it can be:

taken back in person by the reporter and/or the cameraman
sent back via motorbike despatch rider
transmitted from an ENG microwave or SNG microwave truck.

The first two are obvious and so we need not concern ourselves any further. The third option is of course what we are focused on – and in any case, is the norm nowadays for sending material in this type of situation from location back to the studio.

As it turns out, the newsdesk – realizing the scale of the story once the reporter was on the scene – had despatched a microwave truck down to the location at 4.00 pm. The ENG microwave or SNG truck (for our purpose here it does not matter which) finds a suitable position, and establishes a link back to the studio, with both programme and technical communications in place.

By just gone 5.00 pm, the tape material (rushes or edited package) is replayed from the VTR in the truck back to the studio.

Going live

The reporter may actually have to do a ‘live’ report back to the studio during the news bulletin, and this is accomplished by connecting the camera to the microwave link truck (along with sound signal from the reporter's microphone) either via a cable, a fibre optic connection or using a short-range microwave link […].

From the studio, a ‘feed’ of the studio presenter's microphone is radioed back to the truck, and fed into an earpiece in the reporter's ear, so that the studio presenter can ask the reporter questions about the latest on the situation. The reporter will also be provided with a small picture monitor (out of camera shot) so that they can see an ‘off-air’ feed of the bulletin.

This is commonly known as a ‘live two-way’, and what the viewer sees is a presentation of the story, switching between the studio and the location. […]

Typical transmission chain

We now have all the elements that form the transmission chain between the location and the studio, enabling either taped or live material to be transmitted.

The camera and microphone capture the pictures and sound. The material is then perhaps edited on site, and then the pictures and sound – whether rushes, edited or ‘live’ – are sent back via the truck (ENG microwave or SNG) to the TV station.

The processes that occur at either end of the chain are the same no matter whether the signals are sent back via terrestrial microwave or via satellite.

[…]

Activity 7

Earlier we saw that Taylor suggested eight areas in which digital methods promised improvements:

More efficient newsgathering.
More options for getting the story back.
Faster post production.
Greater editorial freedom.
Broad multiskilling opportunities.
Easier automation.
Improved technical quality
Lower operating costs.

Can you see any of these appearing in Higgins's description?

Discussion

Of Taylor's suggestions for where digital methods promised improvements, the area that I particularly noticed was number 5, multiskilling, because Higgins explicitly discusses this, and gives examples of:

a cameraman who can record sound and edit tape; a reporter who can also edit tape and/or shoot video and record sound … or microwave technician who can operate a camera and edit.
Higgins (2004)

Higgins says that the multiskilling was motivated by the need to reduce costs. Assuming the desired outcomes were realised, this is evidence of number 8, lower operating costs.

Several of the others are implied by Higgins, although maybe not made explicit. For example, he describes the use of laptop computers to do editing in the field. This is likely to deliver ‘faster post-production’ and ‘greater editorial freedom’.

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3.2 ICT processes in newsgathering

The Open University — Mon, 18 Jul 2011 08:33:16 GMT

The generic diagram of a communication system, as discussed previously, is shown in Figure 3. If we think of newsgathering as communication from the reporter in the field (User 1) to news editors in the studio (User 2), then we can relate some of the processes described by Higgins to the processes in the boxes. Note in particular Higgins’ summary of the ‘typical transmission chain’:

Higgins (2004)

Figure 3 Generic diagram of a communication system

So at the transmitter we have:

Receives from User 1. This is done by the camera and microphone, which convert the image and sound to electrical signals.
Manipulates. Editing on site is an example of manipulation.
Send. The transmitter on the truck sends the signals via microwave.
Stores/retrieves. Higgins describes the material being recorded to tape (remember that the unedited recorded tapes are referred to as ‘rushes’), and then retrieved (either the rushes or edited) to send back to the studio.

The only network activity described here is ‘conveying’. The main focus of Higgins's description involves conveying via microwave, but he also makes reference to taking the story on tapes back in person or using motorbike despatch rider.

Equipment at the TV studio, including video servers and the computers used by the editors, constitute the receiver. Here, the microwave signal (or the tapes) is received, and manipulated if any further editing is required. If the item is not being broadcast live then it will be stored and subsequently retrieved at the time of broadcast – presumably it is in any case stored for archive purposes.

I shall now look in more detail at some of the technology used in the field.

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4.1 An introduction to the camcorder

The Open University — Mon, 18 Jul 2011 08:33:16 GMT

The development of portable camcorders capable of recording long sequences of high-quality video has been important for newsgathering, but camcorders are also very popular consumer items. In this section I shall be looking in more detail at elements of a camcorder, using it as an example of an ICT system which you are probably familiar with to some extent. Even if you have not used one yourself you will have seen them being used or seen them in shops. (If you get the opportunity, you may like to have a look at a modern digital camcorder in a high-street shop.)

‘Camcorder’ is a contraction of ‘(video) camera and recorder’. There is an implication in this context that a video camera alone might not record (store) the image. Whereas a film camera always stores an image (on film), a video camera might only convert the image to an electrical signal for display remotely on a TV monitor. For example, you can buy video cameras for domestic security which allow you to view outside your house by displaying the output of a camera on your television. If you connect one of these cameras to a video recorder you can record what you see, but the video camera does not itself contain storage. A camcorder is a combination of the two: the camera which converts the image to an electrical signal and a video recorder which records the electrical signal.

Figure 4 represents a camcorder based on the model introduced earlier in the course.

Figure 4 Model of camcorder

Activity 8

How does Figure 4 differ from the model of a stand-alone computer that you have seen before?

Discussion

The only difference in the diagram is that the model of the camcorder has light and sound as additional inputs.

You would not normally think of a camcorder as a computer, but for our purposes, in the context of ICT, this is a useful starting point. A camcorder does indeed contain a computer which, because it is hidden from the user and it takes inputs from other sources as well as the user, is called an embedded computer. In Figure 4 we draw attention to this feature of the camcorder – the embedded computer – neglecting other features that are for the present purposes irrelevant. Nothing about the shape, the construction materials or the power source appear on Figure 4, for example, although these are all important in other contexts. Also, Figure 4 does not include any details of the things that it shows.

The approach to understanding a device or system by focusing on particular aspects and neglecting details is a common tool of technology, and is known as abstraction. Typically, to analyse a device or system you start at a high level of abstraction, where you consider only very broad features, then move to a lower level of abstraction where you look at more details. This is what I shall do for the camcorder, and in the next section I look at some of the processes involved in receiving light and sound.

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4.2 Sound and light input

The Open University — Mon, 18 Jul 2011 08:33:16 GMT

Figure 5 shows a model of a camcorder at a lower level of abstraction than Figure 4, concentrating on the input of light and sound.

Figure 5 The input of light and sound to a camcorder

Activity 9

Although Figure 5 shows more details of the light and sound input than Figure 4, some other aspects of the camcorder are shown in less detail than in Figure 4. What things have gone, and can you suggest why I haven't shown them?

Discussion

In Figure 5 I have not shown the list of processes – receives, sends, stores/retrieves, manipulates – nor have I shown the oval labelled ‘user’ with the two input/output arrows. I have omitted these things because I am concerned specifically with the light and sound inputs, and the other features would be a distraction for the moment. This is an important feature of abstraction: selecting what is important.

I shall now go on to discuss the components shown in Figure 5 in more detail.

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4.2.1 Microphone

The Open University — Mon, 18 Jul 2011 08:33:16 GMT

A microphone converts sound in the air to an electrical signal. Sounds consist of pressure waves in (usually) the air, and to reproduce a particular sound it is necessary to reproduce the corresponding pattern of pressure waves. A microphone converts the pressure waves in the air to the same pattern of voltage waves on wire. If this pattern of voltage variation is applied to a loudspeaker, the speaker converts the electrical signal back to pressure waves in the air, reproducing the sound.

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4.2.2 Microphone input subsystem

The Open University — Mon, 18 Jul 2011 08:33:16 GMT

We'll now move on to consider the microphone input subsystem.

Activity 10

Is the output from the microphone an analogue or a digital signal?

Discussion

The output from a microphone is an analogue electrical signal. Just as sound in the air involves continuous pressure variations over a continuous range, so the voltage from the microphone varies continuously over a continuous range.

Because I am considering here a digital camcorder, the analogue audio signal will be converted to a digital signal, and this is the main function of the microphone input subsystem. The digital audio signal might also be compressed, and put into a standard format.

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4.2.3 Lens system

The Open University — Mon, 18 Jul 2011 08:33:16 GMT

The function of the lens system is to project an image onto the CCD light sensor. A well-designed system ensures that the image is sharp – in focus – and bright. To achieve this, what is needed is a good-quality glass lens (or rather a series of lenses) and accurate focusing. The brightness of the image depends upon the size of the lens. The bigger the lens, the brighter the image, but bigger lenses are more difficult to make and therefore more expensive. Also, of course, bigger lenses mean bigger and heavier cameras. As so often in technology there are trade-offs between several factors. In this case, brightness of the image (and therefore the ability of the camera to operate in low light levels) interacts with cost, size, weight and image quality. I shall discuss focusing in more detail later, after describing the light sensor.

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4.2.4 CCD light sensor

The Open University — Mon, 18 Jul 2011 08:33:16 GMT

The CCD light sensor is a transducer that converts light to an electrical signal. CCD stands for ‘charge coupled device’, and physically a CCD light sensor is an integrated circuit with a transparent cover. A photograph of one is shown in Figure 6. Under the cover is a rectangular array of light-sensitive electronic components called photosites. You do not need to know the mechanism involved, but each photosite provides an analogue electrical output that measures how bright the light is on that site. Each photosite can therefore contribute one pixel to the detected image. Important parameters of a CCD light sensor are the size of the light-sensitive area and the number of photosites – and hence the number of pixels in the image it can produce.

Figure 6 Picture of a CCD (source: NanoElectronics Japan)

The size of the device is usually expressed in terms of the length of a diagonal line from one corner of the rectangle to the other. As you often find in ICT, advances in the technology lead to a reduction in the size, with the same or better performance and maybe lower cost. CCD sensors are an example of this as Taylor observes in his 2004 updating paper:

[There has been] the widespread adoption of small hand held mini-camcorders producing good quality images from small 1/3rd inch CCDs originally developed for the consumer market. An enormous amount of Japanese development effort has gone into producing high resolution, high sensitivity small CCDs to the point where current 1/3rd inch CCD produces better all round performance than a standard 2/3rd inch broadcast format camcorder of 5 years ago, but at around only 20% of the cost. Now there is a trend to move to 1/5th inch CCDs which will enable even cheaper and more compact camcorders. This lower cost has enabled news companies to put greater numbers of camcorders into the field and gather wider cross section of material.

Taylor (2004)

For high-resolution images large numbers of pixels are needed, and at the time of writing, camcorders can have up to several ‘megapixels’, where one megapixel is 1 million pixels (10⁶ pixels).

Activity 11

If a camcorder has a CCD with an array of 811 pixels horizonally by 508 pixels vertically, how many pixels is that in total? Give your answer to two significant figures using scientific notation.

Discussion

811 pixels horizontally by 508 pixels vertically gives a total of 811×508=411,988 pixels. To two significant figures that is 410,000, or 4.1×10⁵, using scientific notation.

The output from one photosite on a CCD is a measure of how bright the light is at that site. It contains no information about the colour of the light. To get colour information, coloured filters are placed in front of the CCD so that separate photosites measure the brightness in each of the three primary colours of light: red, blue and green.

Some cameras use separate CCDs for each of the three colours whereas others use a single CCD with different coloured filters interleaved over individual sites, but the details of the configuration of the filters does not concern us here. If you want to know more you will be able to find information by searching on the Web.

Instead of using CCDs for light sensors, some cameras use CMOS (complementary metal oxide semiconductor) sensors. There are differences between CCD sensors and CMOS sensors – broadly speaking CCD sensors provide better image quality but cameras using CMOS sensors can be smaller – but at the level of the discussion here they essentially perform the same function.

I shall now return to the lens system of the camera, to explain how it focuses the light.

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4.2.5 Focusing

The Open University — Mon, 18 Jul 2011 08:33:16 GMT

Focusing is done by adjusting the size of the gap between the lens and the light sensor. To get distant objects in focus, the gap needs to be smaller than that required for close objects (see Figure 7 below).

View larger image

Figure 7 Focusing light using a camera lens

In theory the exact gap size is determined by the exact distance to the object being filmed. In practice, one gap size will be adequate for a range of object distances, this range being called the ‘depth of field’.

Focusing in a camcorder is invariably done with an electric motor moving a lens, and there will be a facility to focus automatically (autofocus). Auto focusing is either passive or active.

Passive autofocusing works by a computer embedded in the camera examining the image (from the light sensor) to determine whether it is in focus or not.

Activity 12

How do you decide whether an image is in focus? What do you think the camera's computer can look for to determine whether the image is in focus?

Discussion

You can tell whether an image is in focus by seeing how ‘sharp’ it is. The camera's computer looks for sharp edges – sudden changes in colour or brightness. These abrupt changes will be present only if the image is in focus.

Under control of the camera's computer, the motor will move the lens in and out to find the best focus, identified by the presence of sharp lines in the image.

Active autofocusing works by the camera measuring the distance to the object viewed, and using that to calculate the gap needed between lens and light sensor. It measures the distance by sending out pulses of infrared light towards the object being filmed, and measuring how long it takes the reflected light to get back to the camera. During this time, between sending the pulse and detecting the reflected pulse, the light does a round trip – it travels out and back again. The time the light takes to go one way is therefore half the measured interval. I'll call this time – half the time between sending and receiving the pulse – the transit time.

The speed of light is known, so the transit time can be used to calculate the distance between the camera and the object.

Specifically, the distance from the camera to the object is given by the transit time multiplied by the speed of light.

This can be written much more concisely using

d for the distance to the object
t for the transit time
c for the speed of light.

Strictly c is the speed of light in free space (a vacuum). In the atmosphere – through air – light travels at almost the same speed as in a vacuum, and we can neglect the difference. In glass, however, light travels substantially slower (about two-thirds the speed) and it is necessary to take account of this fact when considering light in optical fibre.

Then I can write:

When writing equations like this, it is a convention that you can miss out the multiplication symbol. Any numbers or letters written next to each other are taken to be multiplied together, so we can write:

Equations relating three quantities in this particular way, where one (in this case d) is given by multiplying the other two (in this case t and c) together, are quite common, and you will be meeting other examples later in this unit. For reasons which will become clearer later, it is useful to draw this type of equation in a ‘formula triangle’, as shown in Figure 8. The quantities that are multiplied together go in the bottom two corners (it doesn't matter which way around), and the thing they calculate goes in the top corner. I am not going to say anything more about the formula triangle for the moment, though it might be a bit mysterious, but it will become clearer later.

Figure 8 A formula triangle

I now want to put in a value for the speed of light, c, so that I will have a formula that allows me to calculate the distance d directly from the transit time t.

The speed of light in metres per second is 3×10⁸. That is to say, light travels 3×10⁸=300,000,000 metres every second. When I am doing calculations related to the focusing of the camera, however, I will find the times I am using will be much smaller than a second and the relevant distances will usually be of the order of a few metres – not three hundred million metres! What I am going to do, therefore, is express the speed of light in terms of how far it travels in one nanosecond (ns), which is one thousand-millionth of a second:

Activity 13

How far will light travel in one nanosecond?

Discussion

Light travels 300,000,000 metres in one second, so in one nanosecond it travels:

So I can express the speed of light as 0.3 m/ns (0.3 metres per nanosecond). But this means that when I write the equation, t represents a time in nanoseconds and d represents a distance in metres. It is important that all the units match. Using a value of c=0.3 m/ns and provided t and d are in nanoseconds and metres respectively, I get:

It doesn't matter which way round you write a multiplication (4×5 is the same as 5×4) and it is a convention always to put numbers before letters, so this would normally be written:

For example, if the transit time is 20 ns, the distance in metres is given by:

So the distance is 6 m.

Activity 14

If the transit time is 14 ns, how far away is the object?

Discussion

The distance in metres is given by:

So the distance is 4.2 m.

Algebra and the use of symbols

The use of symbols to represent numerical values, such as ‘d ’ for distance, ‘t’ for time, ‘c’ for the speed of light, is the starting point for algebra. If you don't like maths this might be worrying, but I hope that when you get used to it – and simple familiarity goes a long way to demystifying algebra – you will see that at least it provides useful shorthand.

If you know that c is being used to represent the value for the speed of light and t a time duration, then you will automatically read c×t as ‘multiply the speed of light by the time duration’. It is helped – when you are used to it – by the fact that the speed of light is nearly always represented by c, and that t refers to time in lots of different contexts. Notice, incidentally, that there is a subtle difference in the use of c compared with d and t, because c is a fixed number, but d and t can change. We say that c is a ‘constant’ whereas d and t are ‘variables’.

Besides the use of symbols being a shorthand, there is much that you can do by ‘manipulating’ them, but you will only be meeting this at a simple level in this unit. There is more about algebra in The Sciences Good Study Guide, Maths Help, Section 9 (Northedge et al., 1997).

Remember that the reason for discussing this calculation was to show that when using active focusing the camcorder can measure the distance to an object by transmitting and detecting an infrared pulse. Active autofocusing therefore involves another output from and input to the camcorder (sending and receiving the infrared pulse). We can show this by adding it to the high-level diagram of a camcorder that was shown in Figure 4, to get that shown in Figure 9.

Figure 9 Model of camcorder with active autofocusing

At a lower level of abstraction, the components of the active autofocusing are shown in Figure 10, together with other relevant components of the camcorder.

Figure 10 Active autofocusing

Figure 10 is similar to Figure 5, but I have removed the detail of the sound subsystem in order to concentrate on the light and focusing subsystems.

Activity 15

Write down what you think is done by each of the following boxes in Figure 10

Infrared transmitter/receiver
Motor output subsystem
Focusing motor

Discussion

The infrared transmitter/receiver receives a digital signal from the rest of the camcorder which instructs it to generate and transmit pulse of infrared light. It also detects the reflected pulse of infrared light which it reports back to the rest of the camcorder in the form of a digital signal.
The motor output subsystem receives a digital signal from the rest of the camcorder which it converts to the appropriate analogue electrical signal that drives the focusing motor.
The focusing motor changes the position of the lenses so that light is focused in the light sensor. It is controlled by the electrical signal it receives from the motor output subsystem.

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4.3 Recorder

The Open University — Mon, 18 Jul 2011 08:33:16 GMT

The descriptions of newsgathering in the extracts by Taylor and Higgins make reference to videotapes because, until recently, tape was the main storage medium used for video. Camcorders had a built-in VTR (videotape recorder) and in the first camcorders the video was recorded as an analogue signal. Camcorders used for ENG (electronic news gathering) now store the video as a digital signal, whatever medium is used for recording. Camcorders are now appearing which can store the digital video on DVDs or on memory cards.

Taylor (2004) compares DVD-based camcorders and memory-card camcorders in his updating paper. An extract from this follows.

[…]

[T]wo quite different solutions are competing for the TV news broadcaster's camcorder business:

DVD based camcorders
Solid state flash memory based camcorders

Ever since the development of the DVD, its potential as a rugged, compact, random access medium has made it attractive to TV news companies as an alternative to video tape for use in camcorders and also as an archive medium. It is not surprising therefore that at least one broadcast equipment manufacturer (Sony) is currently introducing camcorders and field players using the latest ‘blue disk’ DVD technology […] which offers approximately 27 GB recording capacity on a 120 mm disk. At 25 Mbps this provides about two and a half hours of recording. The hope is that the blue disks will soon be compatible with the DVD drives available in standard laptops thus facilitating convenient low cost field editing.

There are a few physical limitations with this solution due to the size of the disk, its susceptibility to vibration and unreliability of the disk burning process at low temperatures. However, careful design is minimising the impact of these limitations and a number of TV news organisations are changing over to DVD acquisition.

Even more exciting, last year [2003] Panasonic showed a prototype completely solid state camcorder (called P2 CAM) using four of the consumer SD [secure data] flash memory cards embedded in a standard PCMCIA package called the P2 card.[PCMCIA (Personal Computer Memory Card International Association) is an industry trade association that creates standards for the memory cards that slot into notebook computers and other small portable devices.] Using 1 GB SD cards each P2 card supplies an initial 4 GB memory capacity. The camcorder holds five P2 cards to give it a total recording duration at 25 Mbps video of about 90 minutes (allowing for audio channels and overheads). Clearly this camcorder totally overcomes the physical limitations which are inevitable with any mechanical recording system and it created enormous interest from the broadcast industry. It is now in production and being evaluated by a number of TV news companies.

The convenience of simply taking the P2 card out of the camcorder and slotting it directly into a laptop computer for editing and downloading to the station server system, via the Internet if necessary, was instantly appreciated. The Achilles' heel of this otherwise ideal solution is the cost of the SD media, but as experience indicates, the cost per Gigabyte of flash memory is reducing by a factor of around 4 per annum. It will not be too long before individual SD cards reach 16 GB capacity at affordable prices. Each P2 card would then be capable of storing nearly five hours at 25 Mbps – more than enough capacity to handle HD [high definition] TV at 100 Mbps! It is also worth noting that Panasonic point out that, unlike tape, the SD cards are ‘non-consumables’ lasting the life of the camera. Therefore only a relatively small number of cards are required for each camera as the content should be downloaded into station servers soon after shooting, thus freeing up the cards and making the cost of the medium unimportant.

When either, or both, of these new acquisition technologies replace video tape based camcorders over the next couple of years the migration of the TV news industry to IT technology will be complete. It will have been an extraordinary revolution in terms of its implementation speed having taken less than 10 years from servers and hard disk editing systems first attracting TV news companies' attention. Remarkably it is only around 25 years since Electronic News Gathering ousted film and ushered in the all electronic era.

Taylor (2004)

Tape, DVD and memory cards use three different physical principles for storing data (Figure 11), and have different merits and limitations.

Figure 11 Storage media

Tape is a magnetic storage medium. In very general terms, data is stored by the orientation of the magnetic field in microscopic particles on the tape. The orientation is set when writing to the tape and detected when reading from it. Tape is cheap and can store large amounts of data, but has the significant disadvantage that it can only be written to and read from sequentially. It is not possible to jump to somewhere in the middle of the tape; you have to run through it to get there. Also, compared with DVDs and memory cards, tape is less robust. It can be quite easily damaged and wears out after repeated use.

A DVD is an optical storage medium. Data is written to it by putting microscopic marks on the surface of the disk. Data is read from it by detecting the presence of the marks, which is done by shining a laser onto the surface and measuring the amount of light reflected. Depending on the type of disk, writing to the disk may be permanent or reversible (for a DVD-RW, rewritable, disk). DVDs are now cheap and robust. Certainly data can be read from the disk any number of times with no significant degradation to the disk, and RW disks can be rewritten many times. DVDs do not need to be read serially like tape because it is possible to jump straight to anywhere on the disk – they are random access.

Memory cards use flash memory, which is an electrical storage medium, used in an increasing range of applications including digital (still) cameras. Microscopic cells in an integrated circuit can be set to a voltage and they remain at that voltage by holding electrical charge even when the power is disconnected, until deliberately changed. Some types of flash memory are random access, but others require sequential access. Writing to and reading from memory cards is faster than with a DVD.

Whereas a tape has to be moved physically through a VTR, and a DVD is spun around as the read/write ‘head’ moves across the disk, there are no moving parts involved in using a memory card. This is what Taylor is referring to when he says they are solid state. Generally speaking, moving parts are more prone to wear and tear and failure, so solid state components tend to be more reliable and last for longer. The equipment for reading and writing to flash memory is therefore more rugged than that for tapes and DVDs.

Activity 16

Using information from the above discussion, answer the following questions about tape, DVDs and flash memory.

Which allow random access when reading?
Which is solid state?

Discussion

DVD and some types of flash memory allow random access, but tape does not. Tape is written and read sequentially.
Flash memory is solid state. Tape and DVDs require moving parts to read and write data.

Taylor makes extensive use of approximate calculations on memory sizes, data rates and recording durations in the extract. It is instructive to ‘unpick’ some of his calculations.

Taylor says that the 27 GB (gigabyte) capacity of the blue disk DVD provides about two and a half hours of recording at 25 Mbps (mega bits per second). A gigabyte is about 1,074,000,000 bytes and there are eight bits in a byte, so 27 GB is about:

(to three significant figures).

One gigabyte is actually 2³⁰=1,073,741,824 bytes, but I don't need all the figures because I only want the answer to three significant figures.

At 25 Mbps this is enough storage for:

Dividing by 60 for the number of seconds in a minute gives 155 minutes, which is indeed ‘about two and a half hours’.

About the P2 cards Taylor says:

four of the consumer SD [secure data] flash memory cards [are] embedded in a standard PCMCIA package called the P2 card. Using 1 GB SD cards each P2 card supplies an initial 4 GB memory capacity.

Taylor (2004)

This is simply saying: 4×1 GB = 4 GB

Taylor then says:

The camcorder holds five P2 cards to give it a total recording duration at 25 Mbps video of about 90 minutes (allowing for audio channels and overheads).

Taylor (2004)

Five P2 cards will store 5×4 GB = 20 GB. That is 20 gigabytes which using a similar calculation to the one we did above, is about 1.72×10¹¹ bits. At 25 Mbps that is enough for:

Dividing by 60 for the number of seconds in a minute gives about 115 minutes. That is rather more than the 90 minutes that Taylor estimates, but we have not taken account of the audio coding or any overheads (Overheads are extra bits that are needed to manage the data – file names, bits to keep the video and audio synchronised, etc.) We don't have any information on how much should be allowed for these other factors, but it seems reasonable that they could account for the difference.

Later, Taylor says:

It will not be too long before individual SD cards reach 16 GB capacity at affordable prices. Each P2 card would then be capable of storing nearly five hours at 25 Mbps – more than enough capacity to handle HD TV at 100 Mbps!

Taylor (2004)

If an SD card stores 16 GB, then a P2 card (which holds four SD cards) can store 4×16 GB=64 GB. Using Taylor's claim that 20 GB is enough for about 90 minutes, 64 GB should be enough for about:

Dividing by 60 for the number of minutes in an hour, that is 4.8 hours, which is ‘nearly five hours’, as Taylor says.

Activity 17

Based on Taylor's statement:

Each P2 card would then be capable of storing nearly five hours at 25 Mbps – more than enough capacity to handle HD TV at 10 Mbps!
Taylor (2004)

approximately what duration of HD TV should a P2 card be capable of storing?

Discussion

We are told that a PCMCIA card can store five hours at 25 Mbps and that HD TV (high-definition television) runs at 100 Mbps, which is four times the data rate. This indicates that a PCMCIA card should be able to store 5/4 hours, which is 1 hour and 15 minutes, of HD TV.

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4.4 Batteries

The Open University — Mon, 18 Jul 2011 08:33:16 GMT

Though batteries are in some ways less glamorous than other components of ICT systems, advances in battery technology are every bit as important to the success of ICT as developments in other areas.

Before I can say anything useful about batteries, however, you need to know some basic ideas about electricity.

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4.4.1 Voltage, current and resistance

The Open University — Mon, 18 Jul 2011 08:33:16 GMT

Voltage (or, more correctly, electromotive force, emf – but I shall follow common practice and just say voltage) is a measure of the force with which electricity is ‘pushed’. Nothing happens, however, unless there is an electric circuit, which is a path from one terminal of a voltage source (the battery, in this case) to the other, along which the electricity can flow (Figure 12).

Figure 12 An electric circuit

If there is an electric circuit, the rate at which electricity flows is determined by the nature of the circuit and the value of the battery's voltage. To quantify the rate at which electricity flows we need to know how much the circuit allows or resists the flow of electricity, and this is determined by a measure known as resistance.

If a circuit has a high resistance, little electricity flows for a given voltage. If it has a low resistance, a lot of electricity flows. Resistance is measured in units called ohms, and the rate of flow of electricity is measured in units called amps. The rate of electricity flow, which we call the electric current, in amps is calculated by dividing the battery voltage in volts by the circuit resistance in ohms.

That is:

Qualitatively, you might be able to see that this is plausible. The bigger the voltage (the stronger the push), the more current will flow. The bigger the resistance, on the other hand, the smaller the current.

The convention is to use symbols, i for current, v for voltage and r for resistance, so we write:

For example, if a battery voltage is 3 volts and the circuit resistance is 10 ohms the current flowing is:

The symbol for amps is a capital A, so this is written as 0.3 A. The symbol for volts is a capital V and for ohms is the capital Greek letter omega, Ω.

One amp is a fairly large current flow for electronic equipment, and quite often it is easier to work in units of 1/1000 of an amp which is 1 milliamp, written as 1 mA. Similarly, a resistance of 1 ohm is very small for electronic equipment and often resistance will be expressed in units of kilohms, kΩ, which are thousands of ohms.

Activity 18

If the battery voltage is 1 V and the circuit resistance 1 kΩ, what is the current flow in mA?

Discussion

1 kΩ=1000 Ω, so the current is given by:

The formula triangle that I introduced earlier can be used with the equation for v, i, and r This time because v is on the top of the fraction, v goes at the top of the triangle, with i and r in the bottom corners (again it does not matter which way around), resulting in a formula triangle as shown in Figure 13. The relationship between voltage, current and resistance represented by this triangle has a special name: it is known as Ohm's law. (Georg Simon Ohm, 1789–1854, was the German physicist who first described this relationship.)

Figure 13 The formula triangle for Ohm's law

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4.4.2 Battery parameters

The Open University — Mon, 18 Jul 2011 08:33:16 GMT

Now that we have covered some background on electricity, I will return to discussing batteries.

Activity 19

What do you think would be the important characteristics of a battery for a portable ICT device such as a camcorder or a mobile telephone?

Discussion

The things that I thought of as the most important were:

Weight: if the device is to be portable it must not be too heavy
Size: for a portable device it needs to be kept small
Running time: the user does not want to have to replace or recharge the battery too frequently
Cost: it should not be too expensive.

I'd like to explore how these parameters are specified in more detail. To make the discussion more concrete I'll compare examples of some of the most widely available types of rechargeable battery. I shall look at two different sizes: AA and C. You are probably familiar with these sizes because AA is widely used in portable radios and CD players while the larger C size is used for torches, bicycle lights and portable stereos, among other things. Batteries described as LR6 and MN1500 are the same size as AAs, while R14 and MN1400 are the same size as Cs.

For each of the sizes I shall compare two battery technologies: nickel–cadmium (abbreviated to the chemical symbols NiCd, or called ‘NiCad’) and nickel–metal hydride (abbreviated to NiMH). At the time of writing, although both NiCd and NiMH batteries are widely available, NiCd batteries are declining rapidly in popularity. I shall have more to say about why this is later, but for the moment it is convenient for my purposes to compare the two technologies.

Batteries produce electricity by a chemical reaction, and nickel–cadmium or nickel–metal hydride refer to the chemicals used in the battery. All NiCd batteries will have some similar characteristics because they use the same chemistry, but different sizes and physical constructions will lead to some differences. Likewise for all NiMH batteries, or any other chemistry.

Some basic data on specific examples of each of these four batteries is given in Table 1.

Table 1: Data based on Ansmann batteries

Size	Chemistry	Voltage	Dimensions		Weight	Capacity	Price
			Height	Diameter
AA	NiCd	1.2 V	50 mm	15 mm	24 g	0.8 Ah	£1.40
AA	NiMH	1.2 V	50 mm	15 mm	24 g	2.1 Ah	£2.50
C	NiCd	1.2 V	60 mm	26 mm	75 g	1.7 Ah	£4.00
C	NiMH	1.2 V	60 mm	26 mm	80 g	3.5 Ah	£7.00

Source: Battery Force

Ah: amp-hours.

All four batteries in Table 1 provide 1.2 volts. This is a consequence of the chemistry used, and the fact that each one is a single ‘cell’. The cell is the basic building block of the battery, and to get higher voltages, cells can be connected together, as shown in Figure 14. This way of connecting cells or batteries, with the positive terminal of one connected to the negative terminal of the next, is know as connecting in series, and results in an output voltage that is the sum of the voltages of the individual batteries. The voltages just add together. You might be familiar with this way of connecting batteries from when you have put batteries in radios or torches, where they are nearly always connected in series.

Strictly the term ‘battery’ should only be used when there is a combination of cells used together, not for the single cells of an AA or C ‘battery’, but this is a distinction that is rarely adhered to.

Figure 14 Cells connected together to get a higher voltage

Batteries using a different chemistry produce different voltages from a single cell. A single cell of an alkaline battery (the technology used for the most common non-rechargable batteries) for example, produces 1.5 volts. The chemistry of NiCd and NiMH is similar, so they produce the same voltage as each other

The battery size, AA or C, characterises the dimensions, expressed as the battery height and diameter.

You can see that the weights of the two AA batteries are the same, and there is only a small difference between the weights of the two batteries. In fact it is only when we come to the battery capacity and the prices that there is a significant difference between the NiCd and the NiMH batteries.

The NiMH batteries are more expensive but have a greater capacity. The units of capacity, Ah, are ‘amp-hours’, amps multiplied by hours. The idea behind this is that you can't specify a single value for the length of time a battery can be used because it depends upon the current being drawn from it. If you draw a lower current the battery will last longer. However if you multiply the value of the current being drawn by the length of time it can be used, you get a constant value: the battery capacity.

For example, a battery with a capacity of 1 Ah could supply 1 A for 1 hour, or else it could supply 2 A for half an hour or 0.5 A for 2 hours. More generally, if a battery can run at a current i for t hours, then its capacity is:

If you know the capacity of a battery and want to know how long it can be used to supply a given current, then you divide the capacity by the current.

The time for which the battery can be used, t , is given by:

Activity 20

The form of these equations should be starting to be familiar by now. Again, the relationship between capacity, running time (t) and current(i) can be represented by a formula triangle. Draw one now.

Discussion

The relationship between capacity, and t was presented in two forms:

and

From either of these, and from what you were told previously, you can see that capacity is the quantity that should go at the top of the triangle, so that the triangle is in either of the forms shown in Figure 15.

Figure 15 Formula triangle relating battery capacity to current and running time

Activity 21

In a test, it is found that a battery can be used for 10 hours supplying a current of 0.4 A.

What is the capacity of the battery in Ah?
If a current of 0.3 A is flowing from the battery, how long can it be used for?

Discussion

capacity=i × t = 0.4 × 10 Ah = 4 Ah
time battery can be used at 0.3 A:

This is 13 hours and 20 minutes.

It is important to appreciate that the figures quoted for capacity and the length of time a battery can be used depend very strongly on the way it is being used and the temperature. Also, a battery does not just suddenly run out of electricity – it is not like a car running out of petrol where suddenly there is no more and it stops. Rather, while a battery is being used the voltage falls and as the battery runs out (goes ‘flat’) its voltage drops more quickly. When specifying a battery's capacity a lower limit to the acceptable voltage is specified, and the battery is defined as flat when that lower limit is reached.

Bearing all this in mind, the values for battery capacity are nevertheless useful for comparisons and estimates of battery performance.

Activity 22

How long could a device which uses 0.1 A be run from each of the four batteries in Table 1?

Discussion

AA, NiCd. Capacity of 0.8 Ah, so it can run for 0.8/0.1 h=8 hours.
AA NiMH. Capacity of 2.1 Ah, so it can run for 2.1/0.1 h=21 hours.
C NiCd. Capacity of 1.7 Ah, so it can run for 1.7/0.1 h=17 hours.
C NiMH. Capacity of 3.5 Ah, so it can run for 3.5/0.1 h=35 hours.

As you can see from Table 1, for the batteries considered here, an NiMH battery has a greater capacity than an NiCd battery of the same size and weight, but costs more. This is generally true for NiMH compared with NiCd batteries, although as NiMH become more widely used their prices are getting lower. These are not the only considerations when choosing batteries. For example, with rechargeable batteries such as these there are also issues as to how easy they are to recharge and how many times they can be recharged. On these considerations, broadly speaking NiMH batteries come out better than NiCd batteries. Another significant consideration is the fact that cadmium is highly toxic (poisonous) and so NiCd batteries should be handled carefully and should not be disposed of with other waste, but should be recycled so that the cadmium is extracted safely. For all these reasons, NiCd batteries are falling out of favour.

Activity 23

Have a look for any batteries that you have, especially rechargeable batteries, and see if they say what voltage they are and what capacity they have. Compare them with those in Table 1. Alternatively, if you don't have any rechargable batteries, you can look for adverts to see what information you can find. (Non-rechargeable batteries don't generally quote their capacity.)

Discussion

I had an AA NiCd battery. It was labelled as ‘1.2 V, 0.65 Ah’. This is lower capacity than the AA NiCd in Table 1. I weighed it on the kitchen scales (on a piece of paper as a precaution, remembering the toxicity of cadmium) and found it was about 55 g. Clearly mine is inferior to some NiCds – heavier and lower capacity – but I don't recall how much it cost (I bought it several years ago).

I also found both NiCds and NiMH batteries advertised in catalogues that I had at home. The catalogue listed NiCd and NiMH batteries with similar capacity to those in Table 1. Some of them quoted the capacity in mAh, which is milliamp-hours. The value in mAh needs to be divided by 1000 to get Ah so, for example, the capacity of a battery advertised as a ‘super high capacity’ NiMH AA battery was given as 2300 mAh. This is equal to 2.3 Ah.

Another important type of battery is based on chemical reactions involving lithium. ‘Lithium Ion’ (Li-ion) batteries are commonly used in laptop computers and other portable ICT equipment.

A complication when comparing Li-ion batteries with NiCd and NiMH batteries is that the voltage delivered by an Li-ion cell is around 3.6 volts, compared with the 1.2 volts of NiCd and NiMH cells. To make fair comparisons of capacity you need to be looking at supplies at the same voltage.

Activity 24

If some equipment requires a 3.6 volt power supply it can use a single Li-ion cell. How many NiCd or NiMH cells would it need, and how should they be connected?

Discussion

To get 3.6 volts from NiCd or NiMH cells, which are each 1.2 volts, three cells would need to be connected in series, as shown in Figure 16.

View larger image

Figure 16 Cells connected in series, for the answer to Activity 24

When the different voltages have been taken into account, the capacities of battery packs using Li-ion batteries are greater than packs using NiCd and NiMH batteries for a given size and weight.

There are other pros and cons to Li-ion batteries, and a particular disadvantage is the need to control more carefully the charging and discharging of the batteries, both to maximise the battery life and for safety reasons.

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5.1 Transmission of electrical signals on wires

The Open University — Mon, 18 Jul 2011 08:33:16 GMT

In the discussions of newsgathering in the Taylor and Higgins papers, you saw the significance of the development of systems that allowed long-distance transmission of electronic signals. Initially transmission used metallic wires (remember Taylor's reference to the importance of the ‘lines infrastructure’ and his mention of the ‘wire picture’) and later wireless transmission (terrestrial and satellite microwave) became important. In this section I shall look at some aspects of the transmission of digital signals, starting with a close look at the transmission of electrical signals on wires.

Using a wire to transmit a signal is simple in principle: you operate a switch at one place and observe the effect somewhere else. In Figure 17 I have shown this as a light coming on at a remote location. Notice in this diagram the standard symbol for a battery consisting of two parallel lines, one shorter than the other, and the symbol for a light bulb which is a circle with a cross in it. The standard symbol for a switch that can be ‘open’ or ‘closed’ consists of two dots and a line which either connects the dots (when the switch is closed as in Figure 17b) or misses one of the dots (when the switch is open, as in Figure 17a). To switch the light on you close the switch so that there is an electric circuit from the battery to the light bulb and back again. To switch the light off you open the switch to ‘break’ the circuit.

Figure 17 Switching a light on at a remote location: (a) light off; (b) light on

When you switch a light on, the light appears to come on immediately. There does not appear to be any delay between operating the switch and the effect at the light (although, depending on the type of light there might be a delay before it comes on fully – this is especially noticeable with fluorescent light tubes). In reality there is a delay – it is just very short indeed.

To get a better insight into what is happening, imagine measuring the voltage between the wires. This can be done with something called a voltmeter (Figure 18). A voltmeter has two wires and a display. When you touch the ends of the wires to the terminals of a power source like a battery, the display on the meter tells you what the voltage is between the terminals.

View larger image

Figure 18 A voltmeter

Imagine using the voltmeter to measure the voltage between the two wires at some point between the switch and the light, as in Figure 19. When the switch is open (off) the reading on the meter will be zero. When the switch is closed (on), the reading will (ideally) be equal to the voltage of the battery – which I shall assume is 1.2 volts. Now imagine having the voltmeter touching the wires while the switch is changed from open to closed. In this case you will see the voltage change from 0 to 1.2 V.

Figure 19 Measuring the voltage across a pair of wires

Now, if the voltmeter is touching the wires right next to the switch, you would see the voltage rise from 0 to 1.2 V at the same instant as the switch is closed. If, on the other hand, the voltmeter is touching the wires further away from the switch there will be a delay between the switch closing and the voltage rising. We can display this by plotting graphs as shown in Figure 20.

Figure 20 The voltage across wires when a switch is closed: (a) voltage across the wires as measured at the switch; (b) voltage across the wires as measured 200 m away from the switch

These graphs show how the reading on the voltmeter changes with time. Along the horizontal axis from left to right corresponds to time passing, and up the vertical axis corresponds to increasing voltage, as measured by the voltmeter.

By convention, the axis that goes across the page is the ‘horizontal’ axis, and the axis that goes up and down the page is the ‘vertical’ axis. Sometimes they are called the x and y axes, for horizontal and vertical respectively.

The time axis is labelled in units of microseconds, where one microsecond is one-millionth of a second. Notice also that the time axis is relative to some time origin which is labelled 0. The actual time corresponding to 0 as shown on the axis might have been, say, Thursday 20 May 2004, 2.17 pm and 35.031233 seconds, but labelling the axis with that level of detail would be confusing and irrelevant.

Figure 20(a) shows what the voltmeter would do when connected to the wires next to the switch, while Figure 20(b) shows what it would do when connected to the wires 200 m along towards the light bulb. The switch was closed at time 1, on this scale, so the voltage measured next to the switch rises at time 1.

There is a delay before the voltage rises at the voltmeter when it is 200 m along the wire.

Activity 25

How much of a delay?

Discussion

The voltage rises when the time is equal to 2 microseconds. The switch was closed at a time equal to 1 microsecond, so there is one-microsecond delay between the switch being closed and the voltage changing 200 m along the wire.

We can think of the change in voltage moving along the wires. This idea of the change in voltage moving along the wire becomes clear if we think about turning the light on and then off again afterwards. This is illustrated in Figure 21.

Figure 21 A voltage pulse travelling along a pair of wires: (a) voltage across the wires as measured at the switch; (b) voltage across the wires as measured 200 m away from the switch

Here, the switch is closed at time 1 microsecond and opened again at time 3 microseconds. We now have a voltage pulse. Looking at the voltage across the wires 200 m from the switch, both the rise and fall in voltage happen 1 microsecond later, and the voltage pulse has taken 1 microsecond to travel the 200 m along the wires.

I now say ‘look at the voltage’ rather than ‘the value on the voltmeter’. I only introduced the idea of the (idealised) voltmeter to set up the concept of the voltage having a value at some place on the wires.

Activity 26

How fast is the pulse travelling, measured in metres per second?

Discussion

The pulse travels 200 metres in 1 microsecond. 1 microsecond is one-millionth of a second, so in 1 second it would travel 200×1 million metres=200 million metres or 2×10⁸ metres. The speed is therefore 2×10⁸ m/s.

This is two-thirds of the speed of light, which is typical of the speed that electric signals travel along wires.

Activity 27

Assuming that the pulse continues to travel at the same speed, draw a graph of voltage against time for measurements taken 600 metres from the switch.

Discussion

The pulse travels 200 m in 1 microsecond, so it takes 3 microseconds to travel 600 m. The pulse will be as in Figure 22.

Figure 22 A pulse 600 metres along the wires, for the answer to Activity 27

Figures 20 and 21 (and my answer to Activity 27) are simplifications because they have not shown attenuation or distortion. Figure 23 shows the sort of effects that attenuation and distortion might have on a pulse.

Figure 23 Voltage across the wires as measured 200 m away from the switch, showing the effects of attenuation and distortion

Attenuation reduces the height of the pulse, so that it does not reach 1.2 volts any more. Some of the voltage has been ‘lost’ as it travels the 200 metres because some energy from the electricity is absorbed by (very slightly) heating the wires and some energy is radiated into the air as the wires act as a (very inefficient) aerial.

Distortion alters the pulse, rounding the corners and generally changing the shape. Qualitatively, the smoothing of the corners is because the wires do not allow the voltage to change instantaneously – there is a sort of electrical drag as the pulse travels along the wires. More random distortion effects are caused by what is referred to as noise. By analogy with the common meaning of noise as unwanted, meaningless sounds, noise in the context of electrical signals is the unavoidable effect where signals develop unwanted, meaningless distortions.

Attenuation and distortion become worse as the pulse travels further. Amplifiers can be used to compensate for attenuation, but that still leaves distortion, which ultimately limits how far signals can be transmitted along a wire – or indeed any transmission medium. With digital signals, however, regenerators can be used instead of (or as well as) amplifiers to overcome both attenuation and distortion.

The concept of regeneration is that when a pulse has become badly attenuated or distorted, it can be regenerated to produce a new, perfect pulse for onward transmission. This is illustrated in Figure 24. Note that to simplify the diagram I have drawn a single line to represent a pair of wires. The pulses drawn next to the line represent pulses across the pair of wires at that location.

Figure 24 The concept of regeneration

You do not need to know how regeneration is done in detail; you just need to understand that it is possible. The reason it is possible is that with digital signals there is a restricted range of possibilities of what the signal could be. For example, with a binary signal, 1s and 0s might be transmitted on wire by using, say, 5 V to represent a 1 and 0 V to represent a 0. The regenerator ‘knows’ that the only signal it is expecting is something which started out either as a pulse of 5 V or as 0 V. The regenerator decides which of the two possibilities is most likely, and produces a new 5 V pulse or 0 V accordingly. Although there are practical complications, in principle this decision can be very simple. An electrical circuit compares the received voltage with a threshold value (say 2.5 V) and if the received voltage is greater than the threshold the output is a new 5 V pulse, otherwise the output is 0 V.

Ideally, regeneration can be repeated indefinitely allowing transmission over unlimited distances (Figure 25).

Figure 25 Successive regeneration for long-distance transmission

The boxes labelled ‘regenerator’ in Figure 25 are electronic circuits, but interestingly the very first ‘regenerators’ were human beings! Earl electric telegraph systems operated by the opening and closing of a switch at the transmitter having the effect of a pen putting marks on a piece of paper at the receiver. These were digital systems, with ‘marks’ and ‘spaces’ on the paper performing a similar role to 0s and 1s in modern digital systems. In telegraph relay stations, telegraph operators (people) would look at the marks and spaces on an incoming telegraph line and duplicate them on an outgoing telegraph to send the message on the next leg of its journey.

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5.2 Other transmission media

The Open University — Mon, 18 Jul 2011 08:33:16 GMT

Wires are still used to carry electrical signals over short distances. At the time of writing, for example, most connections between telephones in private houses and the local telephone exchange still use wires. The telephone networks within office buildings are mostly connected with wires, and so are many computer networks (local area networks, LANs) within single buildings. However, all longer-distance communication, between towns, cities or countries, uses either optical fibre or microwave systems. Increasingly, even shorter distances use either optical fibres or wireless links of one sort or another.

Many of the concepts described in the previous section for signal transmission on electrical wires also apply to wireless systems (such as microwave) or optical fibres. Pulses are still attenuated and distorted, for example. It is worth, however, briefly looking at some of the characteristics particular to these other transmission media.

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5.2.1 Microwave

The Open University — Mon, 18 Jul 2011 08:33:16 GMT

You saw the importance of microwave transmission for newsgathering in the Higgins extract. The term ‘microwave’ identifies a particular range of frequencies used for radio communications. The range of frequencies that are referred to as ‘microwave’ is not exactly defined (or, rather, slightly different ranges are used in different contexts), but roughly speaking it is from about 200 MHz to 50 GHz. [Remember that MHz stands for megahertz, which is 1,000,000 Hz (10⁶ Hz) and GHz is gigahertz, which is 1,000,000,000 Hz (10⁹ Hz).]

It is possible to transmit digital signals over microwave by using pulses of microwave power to represent 1s, and the absence of microwave power to represent 0s. This type of transmission is known as on-off keying. In practice this is not generally the best way to use microwave for transmission, and more sophisticated ways of putting the data on the radio signal (different modulation schemes) are normally used.

Regeneration is used in microwave transmission systems, but surprisingly long distances are possible without regeneration. In satellite communications, the satellite performs regeneration (as well as some other functions), but that still means that the signal has to travel the distance from the ground to the satellite in one go (and the same distance back). For geostationary satellites this is 36,000 km each way.

Even more remarkable is the microwave transmission that was used to send data back from the Cassini–Huygens space exploration mission to Saturn and its moon, Titan, in 2004/05. The distance between the Earth and Saturn was at that time 1,517,000,000 km! The reduction in the signal strength over that distance is very great, so the power of the signal received back on the Earth is small. In practice this means that the data rate (bandwidth) is small, because there is a trade-off between signal power and data rate. For high data rates higher power is needed. If the power is low, only low data rates are possible. (It is the same if you are having difficulty hearing someone speaking, when you might ask them to speak more slowly.

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5.2.2 Optical fibre

The Open University — Mon, 18 Jul 2011 08:33:16 GMT

In all developed countries, long-distance communication links (which used to be called ‘trunks’, by analogy to ‘trunk road’) nearly always use optical fibre. It is only where the terrain makes it difficult to lay a cable (such as in mountains or, sometimes, between islands) or when a new link is needed quickly and there isn't time to lay a cable that microwave links are used instead.

An optical fibre is a strand of glass or plastic, not much thicker than a human hair, which guides light from one end to the other (Figure 26). The guidance comes about because of an effect known as total internal reflection. This means that light shone in one end of the fibre doesn't come out from the sides of the fibre even if the fibre is bent around corners. The light just travels inside the fibre until it comes to the far end. Because the fibre is so thin it is flexible and, from the outside of a cable with protective plastic coverings, looks and feels much the same as an electrical wire. Signals are conveyed by changing the ‘brightness’ of the light injected into the fibre and measuring it at the far end. Bits are sent by ‘on-off keying’: 1s are represented by light on and 0s by light off.

Figure 26 Optical fibre of the type used for communications. The bare glass fibre is vulnerable to scratches and will break if bent too tightly, so the cable shown has several layers of protective coverings, shown here stripped off layer by layer.

The attraction of optical fibre is that it can be used for very high data rates over long distances. It is this combination – high data rates and long distances – that distiguishes it from wires.

When electrical signals are transmitted over wires the attenuation increases with increasing data rate, so the higher the data rate, the greater the attenuation and therefore the shorter the distance that can be used. So, for example, although signals at 1 gigabit/s can be carried around on wires inside a computer, it is difficult to transmit electrical signals even a few metres at data rates that high. With optical fibre the attenuation is not dependent on the data rate, and the attenuation is anyway very low, so that signals at tens or even hundreds of gigabit/s can be sent for tens of kilometres with the right sort of fibre.

There are other factors to consider, including, as mentioned above, that higher data rates require higher power (which is the case whatever the medium used to carry the signal). Nevertheless, even though optical fibre is generally more expensive to use than wires, optical fibre is the transmission medium to use for high data rates over long distances.

Activity 28

When optical fibre was first developed as a communications medium, it was initially used only for long-distance transmission between cities. More recently it has been used for shorter distances, including many new local area networks (LANs) within office buildings. There is also a debate about how and when it should be used in the links between private homes and the local telephone exchange. From the discussion above, can you suggest why it is now finding applications for shorter distances, where metallic wires were previously used?

Discussion

In recent years the data rates required of many communication links have been increasing. Since the attenuation of wires increases with increasing data rates, many links which previously could use wires cannot do so any more, because the data rates are too high. Where data rates have got too high to use wires, optical fibre is often used instead.

Also, although this was not discussed in the text, the equipment needed for optical fibre transmission has been getting cheaper, making its use more economical in a variety of applications.

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5.3 Signal speeds, propagation times and distance: the formula triangle

The Open University — Mon, 18 Jul 2011 08:33:16 GMT

When signals travel along a wire or optical fibre, or through space, the relationship between the speed, propagation time and distance can be written in three ways, depending upon which one you want to calculate.

If you know the speed and the propagation time and want to know how far the signal will travel, you use:

You should recall that this is the calculation used for the active autofocusing discussed in Section 4.2.5.

I shall use d for the distance and t for the time, as I did earlier. For speed I shall follow the common convention of using v , which comes from ‘velocity’ – but you have to be careful not to get confused with v for voltage, as used in Section 4.4.

So we have

Technically the value for the velocity of something includes both its speed and the direction it is moving in. For our purposes there is no need to distinguish between speed and velocity. I shall just use the word speed and the symbol v.

If you know the distance travelled and speed but want to calculate the propagation time you use:

which can be written:

Finally, if you know the distance travelled and the propagation time, and want to calculate the speed, you use:

These are of course quite general relationships between distance travelled, time taken and speed. We used the same relationship when doing the calculations for autofocusing in a camcorder, and it applies equally for the journey time driving along a motorway or cycling to work, assuming constant speed (or using average speed in the calculation). The relationship between these three terms is displayed on a formula triangle as shown in Figure 27. You can swap the ‘time’ t and ‘speed’ (v) in the lower corners – it doesn't matter which way round these are.

Figure 27 The formula triangle

Earlier I explained how you draw the formula triangle given one of the equations, but what is useful about the triangle is that you can get back to any of the equations from the triangle.

You do this by covering the quantity you want to calculate, and looking at the position of the other two (Figure 28). So if you want to calculate the time, you cover ‘time’ and observe that distance appears above speed, so you calculate time from distance divided by speed. Similarly, to calculate speed, you cover ‘speed’ and observe that distance appears above time so you divide distance by time. For calculating distance, you cover ‘distance’ and note that time is alongside speed, so you multiply the two together.

Figure 28 Using the formula triangle

Activity 29

In Activity 20 you drew a formula triangle for the relationship between battery capacity, current (i) and the length of time a battery can be used (t).

Suppose you know the battery capacity and the time you want to use the battery for. Write down the formula which will allow you to calculate the current. Use the formula triangle to help you.
Suppose a battery has a capacity of 1.8 Ah and is to be used for 20 hours. What is the maximum current that can be drawn from it?

Discussion

You need to use the formula triangle from the answer to Activity 20. If you know time and capacity, you can see by covering i (current) that current will be given by:
If the capacity is 1.8 Ah and the time is 20 hours, the maximum current is:

It is important when doing the calculations that you use consistent units. You could use the standard units known as SI units (see box below), but you don't have to, so long as the units are consistent. For example, if you have speed in kilometres per hour and time in hours, then distance will be in kilometres.

SI units

One way of ensuring that you are working with consistent units is to use the international standard units known as ‘SI’ units, where SI stands for the French words Système International. The SI unit for length is the metre and for time is the second. In SI units, therefore, speed is expressed as metres per second. There is more about SI units in The Sciences Good Study Guide (Northedge et al., 1997).

Activity 30

For a communications satellite to be in a geostationary orbit it has to be about 36,000 km above the Earth. How much delay will be introduced to a radio signal by having to go up to and back down from the satellite? Radio signals travel at the speed of light (3×10⁸ m/s), and you should assume that the signals go straight up and straight down. Note that this assumption – straight up and straight down – simplifies the calculation, and means that you get a value that would be an underestimate to the delay, for all cases except where the communication really is straight up and down (see Figure 29). In practice, communication via the satellite will often use an angled path and therefore have a larger delay.

Figure 29 Path lengths in satellite communications

Discussion

We need the time, so we use:

We first write the distance and speed in consistent units. The speed is in units of metres per second (3×10⁸ m/s) but the distance is in kilometres (36,000 km). The multiplier ‘kilo’ is ×1000, so in metres the distance is 36,000×1000 m=36,000,000 m=3.6×10⁷ m. This is the distance to or from the satellite. One ‘hop’ – up and down – is twice this distance, 7.2×10⁷m.

So we have:

You might think that 0.24 seconds (about a quarter of a second) is not very long, but in fact if you were having a conversation with someone and there was a delay this long, it would be quite noticeable – and something of a nuisance. When you say something then stop to wait for a reply, it takes a quarter of a second for what you say to reach the other person, then there is another quarter of a second delay before the reply reaches you. So, in total, there is half a second delay (in addition to the recipient deciding what to say) between you finishing what you say and hearing the reply.

Activity 31

Satellites are frequently used for transatlantic communication, but the alternative is to use undersea cables. These days undersea cables would invariably use optical fibre. Light in fibre travels at about 2/3 of the speed of light in the air (light travels more slowly in glass than in the air) and therefore the signal speed is about 2×10⁸ m/s. The distance across the Atlantic (depending upon where you start and finish) is about 4000 km. How long does it take for a signal to cross the Atlantic travelling through optical fibre?

Discussion

We need the time, so we use:

We first write the distance and speed in consistent units. The speed is in metres per second, m/s. The distance is in kilometres, so we need to change it to metres. 1 kilometre is 1000 metres, so 4000 km is 4000 × 10³ m=4×10⁶ m.

So,

You will have seen from the last activity that the delay when using optical fibre is very much less than when using a geostationary satellite. This is not the whole story, because there may be further delays when signals are manipulated (which can happen both with satellites and optical fibre links), but nevertheless it remains true that in speech telephony there is a noticeable delay when the communication uses a geostationary satellite, but not, usually, when it uses a fibre link. Delays used to be commonly encountered when you telephoned the USA from the UK, but that is rare these days because most transatlantic calls are via optical fibre links. It is important to appreciate that the large delay when using geostationary satellites comes about because geostationary satellites are so far from the Earth. Other satellites are also used whose orbits are much closer to the Earth. Communication via these non-geostationary satellites can have a smaller delay, but there are other complications because the satellite is moving relative to the Earth's surface.

As you saw in the Taylor extract in Section 2, news broadcasts often use geostationary satellites and therefore suffer from the larger delay. The processing (manipulation) used in MPEG encoding, especially motion compensation, adds yet more delay. The combined delays of transmission and processing can cause problems for live news broadcasts, as Higgins discusses later in his book:

The interaction in a ‘live’ two-way interview requires that both the questions and answers are delivered as smoothly as possible, but the delay of the compression process which is then added to the fixed satellite delay means that these interviews often have an awkward hesitancy about them.

This can be masked to a degree by imaginative techniques used both in the studio and out in the field, but there is always the evident hesitation between interviewer and interviewee. These compression delays (‘latency’) have reduced as the computational advances in processing speed have increased.

The viewer is also growing more tolerant of these delays to the point where they are hardly noticed, and so the problems are diminishing as time passes.

Some coders also offer a facility to improve the latency at the expense of movement compensation [motion compensation] – the so-called interview or low-delay mode. This is selected via the front panel menu of the MPEG-2 coder, reducing the overall processing time of the signal.

Changing production techniques is by far the best way to try to overcome these awkward pauses. It is common for the studio to cue the reporter a fraction of a second earlier than normal, so that by the time they respond, the delay has passed unnoticed.

Often you will see reporters in the field looking thoughtful or slowly nodding after they have replied to a question, so that it makes their eventual answer to the next question look as if it is very carefully considered reply! Like many other things in TV, much can be achieved by using ‘smoke and mirrors’!

These techniques of course do not work if it is a straight ‘down the line’ interview with a member of the public, who naturally is unaware of these tricks of the trade.

However, you can often see this all going horribly wrong even with a seasoned reporter if there is a studio presenter asking questions who does not appreciate the subtle techniques required to cope with satellite and compression delay.

Classically this happens when part way through the answer from a reporter in the field, the presenter interjects with a supplementary question or comment. The field reporter carries on for a second or so, then halts in their tracks, meanwhile the studio presenter realises their mistake and urges the reporter in the field to continue – and you get a cycle of each end saying ‘Sorry, please go on’.

This was a lesson that had to be learnt in the early days of satellite broadcasting which became more acute when digital processing and encoding was introduced – yet you still see these problems occurring today.

Higgins (2004)

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6.1 Reliable information

The Open University — Mon, 18 Jul 2011 08:33:16 GMT

Information is worthless if you have no trust in it. This has always been the case, but there are issues of trust that arise specifically in the context of modern information and communication technologies. Think about the following:

You do a search on the Web and get results from several different sites. Do you trust the information in them all? How do you decide which are the most trustworthy?
You get an email, a letter or a phone call purporting to come from your bank, recommending a change to your account. Do you follow the advice that you are given?
You read a story in a newspaper, hear it on the radio or see it on TV. Do you believe it? Does it make any difference if it is accompanied by a photograph?
In each of these cases there are two elements to your trust:
1. The authority of the information source. Do you trust the BBC, ITN or someone you've never met writing a weblog? The Guardian or the Daily Mail? Your bank?
2. Authentication of the message – does it really come from whom you think it does? Is it really the BBC's website you are looking at? Does this person writing a weblog really live in Iraq? Is the email, phone call or letter really from your bank?

Authority of OU teaching material

It may be dangerous to raise this question … but do you trust what you read in OU courses? What grounds are there for trusting us?

I hope that you do trust the OU – but not unquestioningly because we do get things wrong sometimes. The Open University ‘brand’ comes with some authority, and there are mechanisms within the University procedures to ensure the quality of OU material. These procedures include:

Team working. This unit, for example, has emerged from course team discussions, and drafts which have been read and criticised by the whole course team.
External consultants. Experts from outside the University are asked for advice and contribute in various ways.
External assessors and examiners. OU regulations require that senior academics from other universities approve courses both during the production phase and annually during the course's presentation.

Further procedures operate at higher levels within the OU structure and formally the quality of all university education in the UK is monitored by the QAA: Quality Assurance Authority for Higher Education.

It must also not be forgotten that when the course is in presentation large numbers of Associate Lecturers and students read the material and provide feedback if they identify problems.

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6.2 Authority and the variety of information sources

The Open University — Mon, 18 Jul 2011 08:33:16 GMT

Technology has massively increased the number and variety of news sources that we have access to. We still have printed books, magazines and newspapers, while digital techniques have increased the number of broadcast radio and TV channels that we can get. On the Web we have access to online versions of many of these. This allows us access to media that previously would have been inaccessible.

With traditional news sources such as these, we have some understanding of the authority that they bring with them. Newspapers, for example, rely to some extent on their reputation. This may be damaged – they might lose readers – if their stories are found to be wrong or misleading, so it is in their own interests to maintain standards. Also, in the UK, newspapers and magazines are regulated by the Press Complaints Commission, the PCC. There are similar considerations that apply to radio and TV to maintain standards. In all these cases there will be some degree of editorial control over the content, and one of the responsibilities of the editors is to maintain standards of honesty appropriate to their publication or channel.

The PCC is a form of self-regulation rather than statutory regulation (regulation by law), and some people argue that this is inadequate.

On the internet, however, there are sources of news and information that are completely unregulated. The technology is such that with a minimum of knowledge and little expense, virtually anyone (in the developed world anyway) can say almost anything they like on a personal web page or a weblog, and, in principle at least, their words are instantly available to millions of people all over the world. The absence of any regulation or external editorial control might be thought to devalue personal web pages or weblogs as sources of news, but there are other considerations. To what extent do websites gain authority by the number of other sites that link to them, and by who links to them? Can personal recommendations replace recognised authorisation? And anyway, perhaps regulation sometimes becomes censorship, and who has the right to determine the editorial ‘line’?

I raise these questions because they highlight issues that arise from the development of the Web, but there are no simple answers. We can gain some insight into the issues involved, however, by looking at one particular example where a weblog was able to provide news that was simply not available through any other source.

The example that I shall use is that of the ‘Baghdad Blogger’, Salam Pax, who was posting reports from Baghdad in the run-up to, and all through, the 2003 war in Iraq. As the US and British troops advanced on Iraq, news was coming from several sources, most of which might be suspected to be censored in some way. Salam was a resident of Baghdad who did not set out to be a reporter, but whose interest in the Web led him to create a weblog that became seen by many as providing a valuable insight into life in Baghdad at this time.

In the article below (itself taken from one of the traditional news sources: the Guardian newspaper), Salam Pax (2003) writes about his experiences. As you read it, think about some of the questions that I asked earlier, but also notice the role of the technology.

‘I Became The Profane Pervert Arab Blogger’

S. Pax, 9 September, 2003, The Guardian

My name is Salam Pax and I am addicted to blogs. Some people watch daytime soaps, I follow blogs. I follow the hyperlinks on the blogs I read. I travel through the web guided by bloggers. I get wrapped up in the plot narrated by them. […]

We [the Iraqi people] had no access to satellite TV, and magazines had to be smuggled into the country. Through blogs I could take a peek at a different world. Satellite TV and the web were on Saddam's list of things that will corrupt you. Having a satellite dish was punishable with jail and a hefty fine […]

While the world was moving on to high-speed internet, we were being told it was overrated. So when in 2000 the first state-operated internet centre was opened, everybody was a bit suspicious, no one knew if browsing news sites would get you in trouble. When, another year later, you were able to get access from home, life changed. We had internet and we were able to browse without the minders at the internet centres watching over our shoulder asking you what that site you are browsing is.

Of course things were not that easy, there was a firewall. A black page with big orange letters: access denied. They made you sign a paper which said you would not try to get to sites which were of an ‘unfriendly’ nature and that you would report these sites to the administrator. They blocked certain search terms and they did actually have a bunch of people looking at URL requests going through their servers. It sounds absurd but believe me, they did that. I had a friend who worked at the ISP and he would tell me about the latest trouble in the Mukhabarat [secret police] room.

[…] With blogs the web started talking to me in a much more personal way. Bits of news started having texture and most amazingly, these blogs talked with each other. That hyperlink to the next blog – I just couldn't stop clicking. […]

To tell you the truth, sharing with the world wasn't really that high on my top five reasons to start a blog. It was more about sharing with Raed, my Jordanian friend who went to Amman after we finished architecture school in Baghdad. He is a lousy email writer; you just don't expect any answers from him. […]. So instead of writing emails and then having to dig them up later it would all be there on the blog. So Where is Raed? started. […]

The first reckless thing I did was to put the blog address in a blog indexing site under Iraq. I did this after I spent a couple of days searching for Arabs blogging and finding mostly religious blogs. I thought the Arab world deserved a fair representation in the blogsphere, and decided that I would be the profane pervert Arab blogger just in case someone was looking.

Putting my site at that portal (eatonweb) was the beginning of the changing of my blog's nature. I got linked by the Legendary Monkey and then Instapundit – a blog that can drive a stampede of traffic to your site. I saw my site counter jump from the usual 20 hits a day to 3,000, all coming from Instapundit – we call it experiencing an Insta-lanche (from avalanche) […]

What really worried me was the people writing those emails were doing so as if I was a spokesman for the Iraqi people. There are 25 million Iraqis and I am just one. With the attention came the fear that someone in Iraq might actually read the blog, since by now it had entered warblog territory. But Mr Site Killer still didn't block it. I preferred to believe they were not watching. They were never patient. If they knew about it I would already have been hanging from a ceiling being asked about anti-governmental activities. Real trouble comes when big media takes notice and this happened when there was a mention of the blog and its URL in a Reuters piece […]

By the end of January war felt very close and the blog was being read by a huge number of people. There were big doubts that I was writing from Baghdad, the main argument being there was no way such a thing could stay under the radar for so long in a police state. I really have no idea how that happened. I have no idea whether they knew about it or not. I just felt that it was important that among all the weblogs about Iraq and the war there should be at least one Iraqi blog, one single voice: no matter how you view my politics, there was at least someone talking.

I was sometimes really angry at the various articles in the press telling the world about how Iraqis feel and what they were doing when they were living in an isolated world. The journalists could not talk to people in the street without a Mukhabarat man standing beside them. As the war came closer, my blog started getting mentioned more and more. There were people quoting it even after I told them not to, because I feared it would attract too much attention. I talked to as few people as possible and did not answer any interview requests, but my blog was popping up in all sorts of publications. The questions people were asking me became more difficult and the amount of angry mail I was getting became unbelievable. Raed thought I should start panicking. People wanted coherence and a clear stand for or against war. All I had was doubt and uncertainty.

[…]

Activity 32

One issue with weblogs as a source of news is that they present just one individual's perception of events, arguably with no more authority to speak than anyone else. Salam makes two apparently contradictory statements about this issue in the article. Pick out these two statements.
What was it that led to a sudden increase in the number of people looking at Salam's website?
What might lead you to trust the content of Salam Pax's blog?

Discussion

The two statements that I picked out are:

‘What really worried me was the people writing those emails were doing so as if I was a spokesman for the Iraqi people. There are 25 million Iraqis and I am just one.’

and

‘I just felt that it was important that among all the weblogs about Iraq and the war there should be at least one Iraqi blog, one single voice: no matter how you view my politics, there was at least someone talking.’

These seem to be contradictory, but maybe there just isn't a simple answer.
Salam says that the number of ‘hits’ on his blog – the number of times someone looked at his site – rose from 20 per day to 3000 following his site being linked by ‘Legendary Monkey and then Instapundit’. Specifically, he says that the 3000 were all coming from Instapundit.
The fact that other people and organisations, whom you already trust, are implicitly or explicitly endorsing Salam Pax's blog might give you confidence in it. It seems that ‘Instapundit’ already had the confidence of many people when it provided a link to ‘Where is Raed?’, and its being mentioned by Reuters would have given it some authority. Personally, it was when it appeared in the Guardian that I first came across it, and I assumed that the Guardian would have made some checks on its authenticity.

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6.3 Authentication of information

The Open University — Mon, 18 Jul 2011 08:33:16 GMT

When I watch TV news, listen to the radio or buy a newspaper I never think to question whether I really am watching ITV, listening to Radio Five Live or getting the Guardian. In each of these cases it is theoretically possible that they are not who they say they are, but the practicalities of performing the masquerade are so complicated that the possibility can be discarded.

With emails and websites it is a very different matter. Indeed, in recent months I have received several emails apparently coming from organisations, such as Microsoft and NatWest bank, which I know were fake. They looked entirely authentic, with the correct graphics, and the first time I received one of these – apparently from Microsoft – at first sight I was taken in. However, from other sources of information I learned that ‘scams’ such as these were in circulation and Microsoft and the major banks have said that they will never use emails to ask for personal information.

The authentic appearance of the emails was meaningless, since it is almost trivially easy to copy images from websites and paste them elsewhere, such as into emails. Incoming telephone calls are equally suspect, and again there have been cases of scams whereby a caller claims to be from somewhere they are not.

Letters with official documents have in the past been more reliable, since it was difficult to reproduce headed notepaper accurately. It is still possible to generate official documents that are hard to imitate (through the use of watermarks or embossing, for example) but the availability of high-quality colour printers has made it easier to produce official-looking documents.

Activity 33

Suppose you are contacted by email, telephone or letter and you want to check whether the communication is authentic. What could you do?

Discussion

If you already have a contact number for the organisation that has contacted you, you could call them and ask about it. This only works, of course, if you already have the number which you know is correct. Email scams often contain a phone number, but that number is, of course, bogus.

A personal signature on a letter changes the situation, provided you know the signature, can recognise it and it isn't a photocopy. The signature is the authentication of the letter. Similarly, recognising the voice of someone on the telephone authenticates the call. Authentication of emails is also possible by the use of digital signatures. A digital signature is a special piece of data which is added to a message. Software on the recipient's computer can analyse the message and the signature and determine whether the message is authentic. Digital signatures only work if your computer already ‘knows’ about the sender.

The technology of digital signatures can be used to authenticate websites as well as emails. In this case, your web browser checks the certificate of the site. This is usually done automatically, with your browser reporting to you if there is a problem.

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6.4 Pictures

The Open University — Mon, 18 Jul 2011 08:33:16 GMT

It used to be thought that a photograph could provide proof of an event – someone could be caught red-handed by a photograph, as proof of their guilt. ‘The camera never lies’, it was said. If you have a digital camera and have been ‘touching up’ photographs on your home computer you will know that this is far from true now. It is easy to lie with a digital photograph.

The idea that the camera never lies has always been a myth, however. As far back as 1917 the photographs of the Cottingley Fairies ‘proved’ the existence of fairies. Two girls, Elsie Wright (age 16) and Frances Griffiths (age 9), took photographs of themselves apparently in the company of fairies (Figure 30). Eventually, in 1981, the girls admitted that they had faked most of the pictures – although they always maintained that one of them was genuine.

Figure 30 The Cottingley Fairies

The difference today is the ease with which digital photographs can be manipulated. It is argued that because of this, digital photography is qualitatively different from analogue photography.

One of the benefits that Taylor claimed for digital techniques is the improved options for editing, and he contrasted digital techniques with analogue techniques where ‘stories cannot easily be altered’. The counterpoint to this is that digital stories can be easily altered – which makes them all the more unreliable.

This has sparked a debate about the changing nature of photography. The artist David Hockney, who has used photography in his work, has argued that the ease of editing digital images has made photography a dying art. Hockney's views were discussed in a newspaper article in 2004.

Hockney says he believes modern photography is now so extensively and easily altered that it can no longer be seen to be true or factual. He also describes art photography as ‘dull’.

Even war photography, once seen as objectively ‘true’, has now been cast in doubt by the ubiquitous use of digital cameras which produce images that can be easily enhanced or twisted.

Hockney points to the case during the Iraq war when the Los Angeles Times sacked a photographer for having superimposed two images to make them more powerful.

Not everyone entirely agrees.

Russell Roberts, head of photography at the National Museum of Photography, Film and Television, said Hockney's argument was ‘simplistic’.

Mr Roberts said manipulation of images was as old as photography. He could cite numerous examples from the 1840s, the first decade of photography, of images which claimed to be accurate depictions of events but were in fact highly stage managed.
[…]
Eamonn McCabe, a former picture editor of the Guardian, said it had become increasingly difficult for picture editors to tell whether a picture had been manipulated and a growing number of digitally manipulated pictures were being published.
‘I think there was perhaps a point where there was a general perception that photography was truth, but we have lost that,’ he said.
But McCabe said this did not detract from the value of good photography. ‘To say that photography is dead is faintly ludicrous. It would be better to say that you should be wary of everything.’

Jones and Seenan (2004)

McCabe's measured response to the consequences of digital photography, in contrast to Hockney's more sensational reaction, echos contemporary discussions comparing ICTs with telegraphy, films and electricity. It is suggested that you should be wary of exaggerated, utopian claims about the power of technologies. Likewise you should watch out for exaggeration in claims of the negative consequences of technology. Certainly ICTs have made significant changes in many areas of our lives. I hope, however, that your study of this unit puts you in a more powerful position to think critically about ICTs, and make informed judgements on the consequences of new information and communication technologies.

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7 Summary

The Open University — Mon, 18 Jul 2011 08:33:16 GMT

The theme of this unit has been the impact that information and communication technologies have had on the news industry. I introduced this theme with a short historical overview of technology in the news industry followed by a look at how technology is used for newsgathering.

We have been looking in some detail at aspects of the underlying technologies used in newsgathering, including the basic components of digital camcorders and the methods of signal transmission over wires. We have used some mathematical methods, with a particular emphasis on equations that can be represented with a formula triangle. We have also explored some basic ideas about electricity in the context of the batteries that are needed to supply the power for portable ICT equipment.

Finally we have considered the issue of trust in information, and the way in which recent ICTs have required us to think again about what enables us to trust information.

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Next steps

The Open University — Mon, 18 Jul 2011 08:33:16 GMT

After completing this unit you may wish to study another OpenLearn Study Unit or find out more about this topic. Here are some suggestions:

If you wish to study formally at The Open University, you may wish to explore the courses we offer in this curriculum area:

Or find out about studying and developing your skills with The Open University:

Or you might like to:

Post a message to the unit forum, to share your thoughts about the unit or talk to other OpenLearners
Review or add to your Learning Journal
Rate this unit

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References

The Open University — Mon, 18 Jul 2011 08:33:16 GMT

Higgins, J. (2004) Introduction to SNG and ENG Microwave, Elsevier Focal Press, Oxford.

ITN (2005) About ITN Independent Television News Limited

Jones, J. and Seenan, G. (2004) ‘The camera today? You can't trust it. Hockney sparks a debate’, The Guardian, 4 March 2004.

Northedge, A., Thomas, J., Lane, A. and Peasgood, A. (1997) The Sciences Good Study Guide, Milton Keynes, The Open University.

Pax, S. (2003) ‘I became the profane pervert Arab blogger’, The Guardian, 9 September 2003.

Taylor, E. V. (1995) ‘From newsreels to real news’, paper presented at a colloquium entitled Capturing the Action: Changes in Newsgathering, Institution of Electrical Engineers, London.

Taylor, E. V. (2004) ‘Real news meets IT’, [online] T175, http://students.open.ac.uk/technology/courses/t175, The Open University.

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Acknowledgements

The Open University — Mon, 18 Jul 2011 08:33:16 GMT

The content acknowledged below is Proprietary (see terms and conditions) and is used under licence.

Grateful acknowledgement is made to the following sources for permission to reproduce material within this unit.

Figures

Figure 6 NanoElectronics Japan

Figure 30 The Cottingley Fairies © Science and Society Picture Library

Text

Higgins J., (2004) ‘Introduction to SNG and ENG Microwave’ Elsevier Science.

Pax S., (2003) ‘I Became The Profane Pervert Arab Blogger’, © The Guardian Newspapers Limited.

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Introduction

The Open University — Mon, 18 Jul 2011 08:33:16 GMT

This unit is from our archive and it is an adapted extract from Networked living: exploring information and communication technologies (T175) which is no longer in presentation. If you wish to study formally at The Open University, you may wish to explore the courses we offer in this curriculum area.

Many governments across the world are moving towards the use of information communication technologies (ICTs) to allow citizens to access information and services. This unit introduces you to e-government. You will look at the scope of e-government, the databases that are necessary, the use of biometrics in identification and verification of identity and assess the useability and accessibility of websites.

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Learning outcomes

The Open University — Mon, 18 Jul 2011 08:33:16 GMT

This is what you should have achieved when you have completed your study of this unit:

Understand the concept of e-government, and the associated benefits and drawbacks.
Understand how a relational database differs from a flat database, including the function and construction of a joining table.
Understand some of the basic principles of XML.
Understand the basic principles of biometric identification and verification systems
For a simple database design, identify suitable entities, attributes and database keys.
Explain the significance of false matches and false non-matches in verification and identification, and their role in false positive and false negative identification.
For a given authentication context, identify whether verification or identification is used.
Recognise social, ethical and political issues relating to the use of ICTs.
Analyse a web interface or application for usability and accessibility issues.

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1 E-government

The Open University — Mon, 18 Jul 2011 08:33:16 GMT

In many countries, e-government has become part of government policy. The UK government has a large e-government project under way, as do the governments of the USA, Australia and Japan, to name just a few. The ‘e’ at the start of ‘e-government’ stands for ‘electronic’, and e-government usually refers to the use by governments of ICTs. In many ways e-government is not a single activity but many activities. However, in the UK and many other countries, there is a degree of central coordination of these activities, and this is my justification for referring to e-government as though it were one project.

E-government has many aspects. For instance:

it is an exercise in large-scale ICT project management;
it is designed to modernise the inner workings of government;
it is a large technical undertaking;
it is expensive.

Any of these could be taken as a starting point for an investigation of e-government, however, I wish to focus on one fairly universal aim of e-government projects:

the use of ICTs to transform the delivery of information and services to the public, and to transform how the public accesses that information.

Making information and services available on a large scale requires the extensive use of databases. I will therefore spend quite a lot of time looking at some fundamental ideas about databases. There are three reasons for devoting so much space to databases. The first reason is the importance of databases to e-government projects. Secondly, creating a database is, among other things, an analytical process. The people who specify and design a database have to think carefully about information and how it is used. In that sense, a database represents a way of thinking about information. This sort of analytical approach to information underlies almost any organised use of ICT aimed at making information available. My third reason relates to legacy systems. These are already installed systems, sometimes quite old, that are not designed to work together in the way their modern replacements would. In this context I shall look briefly at XML, which is a coding system widely used in e-government and elsewhere as part of the solution to legacy problems.

I shall also spend quite a lot of time on biometric methods of identification. These are identification methods based on fingerprints, iris patterns in the eye, and other physical characteristics. In digital form, biometric data is increasingly incorporated in, for instance, passports, driving licences and other identity documents. Identification systems, particularly ones based on biometrics, present a number of ethical, social and political issues, and I shall briefly discuss these.

E-government can hardly be successful if the public does not use it. That raises questions of usability and accessibility of the new services. I shall also be looking at some of the factors that affect usability and accessibility.

Finally, I shall look at some critical views about e-government and at proposals for using ICTs to change radically the relationship of government and public.

Throughout this unit I draw on the writings of others. Sometimes I do this because the material I quote is authoritative or official; sometimes I do it because I think the author's view is interesting. In your own written work you will often want to draw on other sources, and it is important to reference your sources when you do so. The examples of referenced works in this unit will show you how to incorporate referenced material into a piece of writing.

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2.1 Modernising government

The Open University — Mon, 18 Jul 2011 08:33:16 GMT

Before we start to look at e-government itself, I would like you to read some quotations. During the 1980s and 1990s, the potential of ICT systems for government was discussed by many commentators, but in the UK the official argument for e-government was set out in 1999 in the document Modernising Government. This document, however, is not specifically about e-government. Rather, it is about the much broader issue of how government should be modernised. Here is an extract:

Earlier this year, a number of ‘Integrated Service Teams’ were set up to identify the practical problems facing people when they use public services. The teams looked at seven of the most common ‘life episodes': leaving school; having a baby; becoming unemployed; changing address; retiring; needing long-term care at home; and bereavement. Some of the most common problems were:

People had to give the same information more than once to different – or even the same – organisations. A mother of a boy with physical disabilities said: ‘I have lost count of the times I have had to recount my son's case history to professionals involved in his care.’
There is often no obvious person to help those most in need to find their way around the system.
There is a lack of integrated information to enable service providers to give a full picture of what help might be available.
There is minimal use of new technology. Most government departments have a website, but few allow people to fill in forms on line. And government websites are not well linked to other relevant sites.

Cabinet Office (1999), p. 23

Referencing: authors and page numbers

The referencing system used here is the author–date system, sometimes called the Harvard system. The author and date are given with the quotation, or near it. This is called the author–date citation, or just the citation. The citation is the link to the reference in the references list at the end. The reference supplies the full bibliographic information for the work cited. You can see my references list at the end of this Unit. (Sometimes the references list is called the bibliography, though strictly speaking a bibliography is not the same as a references list because it can include any relevant publication, whether cited or not.) Turn to the references list and find the reference for the quotation above.

It is not always clear who is the author of a source you are quoting from. This is often the case with official documents, so you have to decide as best you can whom to cite as author. When you are faced with this problem, it is sometimes helpful to look at online library catalogues, such as that of the Open University Library or the British Library, to see what name they give as the author. Enter the title of the document in the catalogue’s search engine, and you should find details of the document. Another possibility is just to put the title in an internet search engine. This will sometimes produce a library catalogue record card.

Where does the page number go? If you only refer to the source once, the page number (or numbers) goes with the information in the references list. If there are multiple references to the same source, the best place is with the quotation, as here

The use of capital letters, italics, quotation marks, brackets, etc., in references varies from publisher to publisher. However, it is usual to italicise book and journal titles.

Activity 1: (self-assessment)

Construct an author–date citation and a reference to accompany a quotation from page 35 of the following book: The Rise of the Network Society, by Manuel Castells, published in 2000 by Blackwell in Oxford. This is the sole reference to this book. You will probably find it helpful to look through the references at the end of this unit.

Answer

The author-date citation is like this:

(Castells, 2000) or Castells (2000) if the author's name is part of a sentence.

The reference is like this:

Castells, M. (2000) The Rise of the Network Society, Oxford, Blackwell, p. 35.

Not all publishers include a place of publication in book references. Sometimes the order of publisher and place is reversed.

This book is actually the second edition of a book first published in 1996, as you may have spotted if you checked it in a library catalogue. The edition number is incorporated as follows.

Castells, M. (2000) The Rise of the Network Society, 2nd ed., Oxford, Blackwell, p. 35.

The extract from Modernising Government identifies typical problems ordinary people can have in dealing with government. The remedy for these and countless other problems, as far as this UK government document is concerned, is ‘modernisation’ of government, and part of this modernisation is the provision of services online. Typical online services would include: making tax payments, viewing a record of payments, contacting government departments and making appointments, finding information about entitlements, and so on. The first and last two bulleted points in the quotation are especially relevant. They point to deficiencies in information and services, and to a lack of integration in what is available. This takes us to the heart of what many governments (not just the UK) view as the essential features of e-government:

Making most, or even all, of the government's services available online.
Bringing online services together, so that the user does not have to go to different departmental websites for different services.

In many countries, putting government services online did not begin with the launching of e-government projects. Individual departments had started to put their services online, both for their own use and for public use, well before these highly publicised e-government ventures were launched. However, a piecemeal approach has led to inconsistent systems, and one of the goals of e-government projects is to bring order and consistency to what would otherwise be chaotic.

Although making government services available online might be modernisation, would it necessarily be an improvement?

Activity 2 (exploratory)

Try to think of some clear advantages of electronic delivery of government services. You might like to look back to the bullet points in the extract above from Cabinet Office (1999) for some ideas.

Discussion

These are my thoughts. Yours might be different.

Services would be available ‘at a distance’ – the user would not have to travel to them.

Services would be available round the clock.

Services might be cheaper, and might be better.

Official documents (white papers, bills, Acts of Parliament, etc.) could be more easily available as downloads from government websites.

Activity 3 (exploratory)

Can you think of any disadvantages that might follow from making these services available electronically?

Discussion

Again, these are my thoughts. Yours might have been different.

People without access to online facilities might find that conventional services are less well supported than before, for instance by being poorly staffed or more awkward to use.

If government cost saving is a reason for introducing electronic services, this saving might be achieved by making the user do work that was formerly done by government staff (for instance, finding information, filling in forms, etc.).

The last two activities have raised the issue of cost saving, or potential cost saving. Some commentators have tried to gauge some of the cost savings from e-government. The following activity asks you to complete one writer's estimate of potential savings.

Activity 4 (self-assessment)

Rachel Silcock (2001) writes:

[…] the Department of Social Security (DSS) handles around 160 million telephone calls each year (with mostly paper-based administrative systems), at an approximate cost of £2.40 per call (based on one of its most efficient call centres). If only 2% of these calls could be shifted to people looking up material on DSS web sites, then an annual saving of […] might be achievable.

Fill in the missing figure in the last sentence of the Silcock quotation by doing the calculation. Hint: you will need to find 2 per cent of 160 million and proceed from there.

Answer

2% of 160 million calls is:

At £2.40 per call, this number of saved calls amounts to a saving of:

As the data on which this calculation is based is only approximate, it is misleading to give such a precise answer. It would be better to round the answer to £8 million.

There would, of course, be the cost of setting up and maintaining the website to set against this, but the setting-up cost should be a ‘one-off cost’ rather than a recurring cost to pay each year. The maintenance cost would be an annual cost, but should be well below £8 million.

Referencing: mentioning the author

If the author is mentioned in the sentence leading up to a quotation, as with the Silcock quotation in the last activity, putting the date in brackets after the author is usually the neatest way of giving the date. (If necessary, the page number can be included with the date.)

Note that by ‘date’ I mean just the year. If the publication were a monthly, weekly or daily (for instance) I would still give only the year. The precise date would be given in the references list.

Activity 4 showed that, in principle, substantial savings could be made if transactions with the government were done online.

The Modernising Government document initially set a deadline of 2008 for making ‘all’ UK government services available online. The ‘all’ was not meant literally. It excluded services which could not be delivered electronically or those for which ‘there is genuinely unlikely to be demand’ (Cabinet Office, 1999, p. 62). A few years after Modernising Government was published, the 2008 deadline was brought forward to the end of 2005, and then relaxed somewhat to allow more exclusions. Nevertheless, the number of government services available online in the UK has expanded greatly, and the same is true of many other countries.

In 2005, Ian Watmore, the head of the UK e-Government Unit, was reported by Say (2005) as having said:

[…] IT in government is as difficult as it gets. Government does things in IT which are more complicated than anywhere in the private sector.

Whatever the truth of this claim, it is not difficult to imagine that implementing e-government is particularly complex. Several issues occurred to me, and I have given them below. You can probably think of others.

Technical issues. How are services to be made available online? Which services cannot be adapted to online delivery? For instance, can voting be done online in a way that everyone will trust? (At the time of writing, systems have been used in the USA that do not allow votes to be recounted, and lack many of the safeguards of paper-based balloting.) Can existing online services be made to work together? (We shall look at some of the issues with so-called legacy services later.)
Cost. All large-scale ICT enterprises cost a lot. Will the benefits of introducing e-government justify the expenditure?
Expertise. Large-scale ICT projects require a great deal of expertise to set them up, and a lot of expertise to keep them running. Is sufficient expertise available?
Management. How do you manage a project such as this, both in the setting-up phase and the running phase?
The user interface is what the user sees (and maybe hears) and interacts with. In an online environment where no one is available to help the user, how easy will it be to use government services?
Usage. Will people want to use online e-government systems?

Issues raised by questions such as these are part of what makes e-government such a complex undertaking. In the UK, an idea of the scale of the e-government project can be gauged from the level and type of government support it has received. Rather than being supervised directly by a government minister, the project has been run by a specially appointed manager, a so-called e-Envoy, with considerable powers and access to high levels of government.

When thinking of services being made available electronically, it is natural to suppose that this means via computers. However, in the UK e-government project other methods of delivery are envisaged too:

The strategy envisages that services will be accessed by multiple technologies, including web sites accessible from PCs, kiosks, mobile phones and digital TV, and call and contact centres.
Cabinet Office (2000), p. 16

A couple of footnotes in the same document clarify what some of these terms mean:

Kiosks are a means of providing access to electronic services in public places. Initially, kiosks tended to use touch-screen technology. More recently, keyboard input and web browsing have greatly improved their capability. […]
Contact centres combine the handling of e-mail, video and telephone calls.

There is no doubt, however, that access to government services via the Web has dominated thinking about e-government, and not just in the UK. This is what I shall concentrate on here.

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2.2 Central and local government

The Open University — Mon, 18 Jul 2011 08:33:16 GMT

In many countries, government can be thought of as having a central component and a local or regional component. In the UK, central government is based in London, although some functions are devolved to the Scottish Executive in Edinburgh, the National Assembly for Wales in Cardiff, and the Northern Ireland Assembly in Belfast (suspended at the time of writing). These devolved assemblies in Scotland, Wales and Northern Ireland are nevertheless forms of central government. Central government is generally concerned with such things as making laws, collecting national taxes (e.g. income tax, VAT), administering the armed services, national transport policy, determining policy on foreign relations, health, social security, and so on.

Local government is concerned with running local services, such as schools, health centres, public libraries, refuse collection, planning permission for buildings, etc. Funding for local services tends to come from a mixture of local taxes (for example, the council tax in the UK) and central government money. According to one UK newspaper, 80 per cent of the public services that people are most concerned with are run by local government rather than central government (Cross, 2005).

Referencing without quoting

Referencing is needed sometimes even when you do not give a quotation. Drawing on data from another source generally needs a reference. In the Cross (2005) example above, no text is quoted, but there is a reference. This is because the statistic about 80 per cent of public services is important, and possibly open to challenge. That is why there is a reference.

When the information you use is common knowledge, or can be found in dictionaries, encyclopedias and other reference works, you do not need to give a reference unless the information is contentious. Very particular information, such as statistical information, however, nearly always needs a reference.

In the UK, e-government is a matter for both central government and local government working collaboratively. However, Musgrave (2005) refers to:

[…] gaps in understanding, and lack of collaboration, between officers in Local and Central Government Services. These findings are symptomatic of a cultural divide between Local and Central Government Services. The culture of non-cooperation across UK government is seen as the most substantial obstacle to sharing services, more so than legal or IT issues.

It is important to appreciate, therefore, that making e-government work successfully is not simply a technical matter. It depends as much on overcoming organisational and cultural differences between central and local government.

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2.3 Styles of presentation

The Open University — Mon, 18 Jul 2011 08:33:16 GMT

One commodity that is dispensed in vast amounts both by central and local government is information, and so this is one of the more obvious candidates for electronic delivery. Online government services are typically approached via a portal site, which is a kind of entry site from which other sites can be reached. The websites of large organisations, such as Microsoft, the BBC and the Open University, are usually portals.

Going into a portal site is a bit like going into a large office building via the main door. Once inside, you have access to all the offices and departments inside the building, which are usually listed on a notice board. Similarly, portals list what is available, but in the form of a set of links. However, portal sites often have links to the sites of other organisations, as well as internal links to departments in the host institution.

An e-government portal site that only offered the user information would be a poor resource. The intention behind e-government is that sites should be transactional, that is, the user should be able to conduct a number of transactions at the site. Transactions involve such activities as paying, applying (for example, for a parking permit), consulting and booking. Transactions depend on the two-way flow of information between the user and the site. Transactional sites of any sophistication make extensive use of databases behind the scenes to hold data of many kinds. In fact, you can think of the site itself as an interface between the user and the many large databases that are needed to underpin the services offered.

In many e-government projects, online services are intended to become more personalised. Typically this involves either providing the user with a personal area on a portal, or providing something like a ‘personal portal’. In a personalised online service, the site appears to ‘know’ relevant information about the user. For example, where he or she lives, the schools attended by members of the user's family, the status of tax payments, etc. This kind of service is intended to be convenient to the user. All the same, it can be disquieting to log onto a website and to find that the system apparently knows a great deal about you. You may have had similar feelings with book-selling websites that know all about your recent purchases and suggest more for you to make.

A personalised portal, just like a transactional one, is underpinned by databases. Personalised portals should also allow the user to make transactions, which are similarly underpinned by databases. Thus, databases turn out to be a crucially important part of the substructure of an e-government system, as they are of many online systems. You will already be familiar with the essential idea of a database, but large-scale information systems such as e-government use more sophisticated databases. I shall discuss these in the next section.

Activity 6 (exploratory)

Find the official website of a local government authority in the UK. (If you live in the UK, you can use your own local authority or another.) A simple way to find a suitable website is to use the search terms ‘council tax’ (use double quotation marks) and the name of a town in a search engine. Not all the links produced will be to a local government website, but you should find one that is. Having found a suitable site, go to its home page and spend about five minutes exploring the facilities on offer. The purpose of this activity is just to familiarise yourself with some of the features of an e-government site.

Discussion

Different local authorities have different sites, so I cannot give an overall comment. You probably found, though, that there was a certain amount of local authority information available, together with facilities for some transactions.

Towards the end of this unit you will look at an e-government site in a more systematic way than you have done in this activity.

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3.1 Tables and flat databases

The Open University — Mon, 18 Jul 2011 08:33:16 GMT

Databases lie at the heart of many e-government systems, and at the heart of many other ICT systems. The local government websites you looked at in Activity 6, for instance, almost certainly used databases a great deal, as do the majority of central government sites. Away from e-government, the websites for Amazon or eBay, for example, use huge databases.

Constructing a database of any complexity requires careful thought about the way information is organised in any particular context. A database can therefore be regarded as the outcome of an analysis of the structure and use of information. The significance of this remark might not be clear at the moment, but should become clearer as you work through this section. Careful analysis of the structure and use of information is a vital part of all large-scale projects such as e-government.

For large, complex information systems, relational databases, which I will describe shortly, are generally used, although relational databases can be used for simpler projects too. It is not the size of a project that dictates the need for relational databases, but its complexity. More specifically, the complexity of the relationships between information in the database is what dictates the need for relational databases. I hope to give you a flavour of what I mean by this in the short example in the following pages.

Relational databases are contrasted with simpler databases known as flat databases. Some people, however, use the term ‘database’ to mean only relational databases, and flat databases are sometimes simply called tables.

To understand what relational databases are and why we use them, we need to appreciate some of the shortcomings of the simpler, flat database. Table 1 is an example of a flat database. It contains information about some fictional students and the local authority evening classes they are studying. As you will recall, in a table like this a column can be described as a field, and each row is a record.

Table 1 Students and evening classes

Name	Address	Postcode	Course1	Course1_Sessions	Course2	Course2_Sessions	Course3	Course3_Sessions
Lodhi, Mona	22 The Grove, Newport	AB12 3CD	Yoga	10	Holiday Spanish	15
Jones, Bob	2 High Street, Stratford	AB6 4PQ	IT for all	5	Oil painting	15
Cherry, Colin	59 Acacia Avenue, Brompton	AB2 12ZY	Digital photography	10	Sewing	15
Cherry, Colin	13 The Limes, Leighton	XY6 7LR	Creative writing	20
Edwards, Delia	40 Eldon Court, Hampton	XY12 4TK	Digital photography	10	Oil painting	15	Ballroom dancing	30
Roberts, Albert	18 Mount Pleasant, Greenhill	AB12 7UB	Drawing	15
Singh, Sara	7 Marina View, Sutton	ABM 8WQ	Woodwork	15
Chang, Patrick	21 Green Lane, Newport	AB12 9TU	Everyday maths	20
Evans, Mary	13 The Limes, Leighton	AB6 7LR	Oil painting	15

This table is quite short, but you could imagine it extending downwards to cover many more students.

Table 1 allows for up to three courses per student, and the fields for them are Course1, Course2 and Course3. Each course has an associated number of sessions, which is the number of classroom sessions in the course. This is shown in the fields Course1_Sessions, Course2_Sessions, Course3_Sessions. (I have avoided spaces in the field names because many database management systems do not permit them, but this is irrelevant to the principles I am outlining here.)

Table 1 could be set up as a spreadsheet. You can think of a spreadsheet as a flat database with a selection of built-in, simple database functions, such as searching and the ability to sort the data in various ways and to perform calculations on it (for example counting the number of students enrolled on each course). A spreadsheet also allows you to display the data as charts, graphs, lists and so on.

Something that databases and spreadsheets share is the concept of a data type. Typical data types are ‘text’ (that is, alphabetic characters), ‘number’ and ‘date’. Usually each field needs to be specified as holding a particular type of data. For example, in Table 1 the fields for course sessions would be defined as having the data type ‘number’. Defining these fields as having numerical data allows arithmetical operations to be performed on the data, such as adding the number of course sessions in each record to find the total number of sessions a student has enrolled for. Similarly, using the data type ‘date’ allows data to be sorted chronologically. So, for instance, if there were a field with the starting dates of the courses, the records could easily be sorted into date order. A further benefit of defining a data type for fields is that it can help prevent the wrong type of data being entered. If a field is defined as containing text data (for instance), the program can perform checks on any data entered to make sure it is the right kind.

Table 1 is a very simple table. Much more data would need to be recorded in a real example, for instance course fees, classroom allocated, course leader's name, course code, start date, and so on. However, Table 1 has other problems which are not due simply to its lack of typical data. These other problems arise because the organisation of the data has not been considered carefully enough. I will come back to this point shortly.

Much of the usefulness of databases as a way of holding data arises from the fact that the data is organised, and can be interrogated in various ways. By ‘interrogated’ I mean that a question can be framed whose answer can be drawn from the database. For instance, a question might be: ‘How many people with a postcode beginning “AB6” are enrolled on courses with 10 sessions or more?’ For a human reader of Table 1, that question is easy to answer, although tedious if the table is big. Getting a computer to answer the question is not so straightforward, because the processes a computer would have to go through are quite complicated. In essence, a small computer program needs to be written to work through the data and to apply appropriate tests. This is done by using what is referred to as a query language. A query language is not quite like a natural language, such as English or French, but has some of the features of a natural language mixed with some mathematical features. A very common query language is SQL, or structured query language. You will see an example of a query using SQL later.

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3.2 Problems with flat databases

The Open University — Mon, 18 Jul 2011 08:33:16 GMT

As a database, Table 1 is messy and inefficient, and does not really qualify as a properly constructed database. For instance, what happens if someone signs up to do four evening classes? To allow for this possibility we could incorporate further fields, such as Course4, Course5 and so on. But how many more fields should there be? If we choose an extravagant number, such as 20, we could be confident that no student would exceed that number of courses in a year, but the table would be wasteful as much of its content would be empty. (Even empty fields occupy space, because information about the structuring of the data must be stored whether the fields are empty or not.)

Another problem with Table 1 is the repetition of some items of data. For instance, the fact that ‘Oil painting’ has 15 sessions is recorded in three places in the table. A principle of good database design is to avoid repeated data such as this. When the same data is recorded in several places, there is always a possibility of clerical errors leading to inconsistency. What is more, changing the data or correcting errors means finding every repetition of that data in the table and changing it or correcting it. For instance, if the teacher on the Oil Painting course decided to add a few extra sessions, incorporating this amendment in Table 1 would mean updating several records. Ideally information about the number of sessions in a course would be recorded in just one place.

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3.3 Entities and attributes

The Open University — Mon, 18 Jul 2011 08:33:16 GMT

A well-designed relational database overcomes the problems outlined in Section 3.2 by using two or more tables, rather than a single table, such as Table 1. This means that the data has to be divided in some way between the tables. The construction of tables is done according to several rules. I will just look briefly at one rule to give you an idea of the underlying principles.

The rule I shall look at states that there must be one table per entity. An entity is an item for which we want to store information. It can be tangible – for example a person or an object – or intangible – for example an event. (Typical events might be a sale, registration or renewal.) An entity can be a concept – for example a bank account.

In Table 1 the most obvious entity is ‘student’. Any particular student, such as Colin Cherry, is an instance of this entity. Entities are the things we store data about in tables. Each piece of information we store is an attribute of that entity. An attribute is descriptive information about an entity. For the ‘student’ entity, attributes in Table 1 are name, address and postcode. In a properly constructed table there is one field per attribute.

You might argue that ‘Course1’, ‘Course2’ and ‘Course3’ are also attributes of ‘student’, and in some contexts that would be reasonable. In this case, though, there is descriptive information about courses, namely the number of sessions they run for. Courses therefore have attributes. In this context, then, ‘course’ is another entity. Whether something is regarded as an entity or not is dependent on the context.

Activity 7 (exploratory)

Does ‘postcode’ have any attributes in Table 1 (see screen 6)?

Discussion

No. There are no attributes of ‘postcode’. There is no descriptive information, or label or other qualifying information about postcodes.

I said above that in a properly constructed relational database we have one table per entity. Table 2 is the table for the student entity and Table 3 is the one for the course entity. I have added a few more fields to the tables to make them more realistic. For instance, Table 3 has a column for ‘Fee’ and a column for ‘Course_code’.

Table 2 Student entity table

Student_index	Family_name	Given_name	Address	Postcode
1	Lodhi	Mona	22 The Grove, Newport	AB12 3CD
2	Jones	Bob	2 High Street, Stratford	AB6 4PQ
3	Cherry	ColinI	59 Acacia Avenue, Brompton	AB2 12ZY
4	Cherry	Colin	13 The Limes, Leighton	XY6 7LR
5	Edwards	Delia	40 Eldon Court, Hampton	XY12 4TK
6	Roberts	Albert	18 Mount Pleasant, Greenhill	AB12 7UB
7	Singh	Sara	7 Marina View, Sutton	ABM 8WQ
8	Chang	Patrick	21 Green Lane, Newport	AB12 9TU
9	Evans	Mary	13 The Limes, Leighton	AB6 7LR

Table 3 Course entity table

Course-code	Course	Sessions	Fee
E01	Yoga	10	£20
E02	Digital photography	10	£20
E03	Everyday maths	20	£40
E04	Oil painting	15	£30
E05	Creative writing	20	£40
E06	Holiday Spanish	15	£30
E07	Woodwork	15	£30
E08	IT for all	5	£10
E09	Drawing	15	£30
E10	Sewing	15	£30
E11	Ballroom dancing	30	£60

The next step is to link the records in these two tables, which I will do shortly. Linking the records in separate tables requires the use of keys. A key uniquely identifies each record of a table. Table 1 did not have any keys. (‘Name’ cannot be a key because, as Colin Cherry shows, names might not be unique.) In Table 2 I have introduced a new column named ‘Student_index’. Each entry in this new column uniquely identifies a particular record. The ‘Student_index’ in fact consists of just the sequential numbering of the records. This is the simplest way to create a key when there is no other key readily available.

The ultimate intention is to link students to courses through the keys. By associating a particular student with a particular course we have a way of representing an enrolment. We need therefore to think about a suitable key for Table 3.

Activity 8 (self-assessment)

In Table 3 I have not numbered the records as a key, as I did in Table 2, because I would like to use the course code as a key. How valid is the course code as a key under the following circumstances?

Courses are presented only once, and never repeated.
Courses are run only once per year, and repeated the following year.
Some courses are run twice or more per year.

Answer

If the course is never repeated, then we can safely use the course code as a key, because the code identifies something unique.
If courses are repeated annually there is a problem with using the course code as a key because it no longer represents something unique. For instance, students enrolling for Yoga in successive years are enrolling for different instances of the course. Each instance of the course would need its own record in the database. However, if the database is made afresh each year, and just covers one year's worth of data, then the problem does not arise and the course code can be used as a key.
If courses are run twice or more per year, there is a problem with using the course code as a key for the same reasons as in (2). That is, each presentation of the course is a new instance (assuming the database has a lifetime of a year or more), and so the code does not represent something unique.

In the following I am going to assume that the course code can be used as a key in Table 3; that is, the conditions in (1) or (2) of Activity 8 apply, with the proviso in the case of (2) that the database holds only a year's worth of data.

Splitting Table 1 into Tables 2 and 3 has lost the relationship between the entities ‘student’ and ‘course’. We can no longer tell who is enrolled for what. The essence of the relational approach to database design is to relate entities to each other by relating their keys. In this example we would do this by constructing a joining table to capture the relationship between entities. Table 4 is my joining table. Student keys are on the left, and the keys from the courses table are on the right. To keep things simple, I am using the course code as the key although, as you saw in Activity 8, this is acceptable only under certain conditions.

I have annotated the table with names so that you can identify the records; but the annotations are not part of the table.

Table 4

Joining table for students and courses

You will notice in Table 4 that student keys can appear more than once on the left, and courses can appear more than once on the right. This follows from the fact that the relationship between the student entity and the course entity is many-to-many. That is to say, one student can enrol for many courses, and each course can be taken by many students.

The entity tables and joining table taken together constitute the relational database. A real example might have many entity tables and many joining tables. It might also have no joining tables – for reasons I will come back to.

Notice how the new relational database solves the problems I identified with Table 1. If someone enrols for several courses, we just add more records to Table 4, as required. Each record in Table 4, therefore, represents the enrolment of a student on a course. We do not need to have empty fields available to accommodate additional enrolments by a student, as we did in Table 1. Also, if there is an administrative change to a course, such as the number of sessions, we need make only a single change, in Table 3. (You will recall that in Table 1, the repetition of the same piece of data in several places meant that administrative changes would require hunting out every occurrence of the data and modifying it.)

The process of organising data efficiently into tables, so that unnecessary repetition is avoided and so that each table represents a single entity and its attributes, is known as normalisation. The process we have gone through with Tables 1, 2, 3 and 4 is a very simple example of part of the normalisation process.

In the light of the normalisation we have just done, we can criticise Table 1 in more appropriate language than before. The trouble with Table 1 is that:

it contains data about more than one entity;
it attempts to capture the relationship between entities.

It is therefore mixing different functions, and this is why it is unsatisfactory.

Activity 9: (self-assessment)

Table 5 is a flat database relating to some regular committee meetings. What are the entities and their associated attributes?

Table 5 Committee information

Committee	Meeting time	Member	Telephone number
Planning	Every Monday a.m.	Jones	1239
		Patel	4728
		Robinson	3589
Recreation	Every Friday p.m.	Jones	1239
		Smith	4633
Education	Final Wednesday of month, p.m.	Patel	4728
		Robinson	3589
		Smith	4633

Answer

One entity is ‘Committee’. The associated attribute is ‘Meeting time’.

Another entity is ‘Member’. The associated attribute is ‘Telephone number’.

I mentioned that some relational databases might have no joining tables. The following activity is designed to show how this might come about.

Activity 10: (exploratory)

What would happen to the joining table, Table 4, if this particular local authority allowed people to enrol for only one course at a time? Write the first few rows of a new joining table on the assumption that each student takes only their ‘Course1’ as shown in Table 1.

Discussion

Table 6 shows the first five rows of the new joining table. Notice that in Table 6 each student key appears only once, reflecting the fact that students are allowed only one enrolment at a time.

Table 6: Modified joining table: one course per student

Student_index	Course_code
1	E01
2	E08
3	E02
4	E05
5	E02

The relationship between the keys in Table 6 could be captured by a simple amendment to the student table, which would remove the need for a joining table. Table 7 shows the first few rows of the modified student table.

Table 7: Modified student entity table

Student_index	Family_name	Given_name	Address	Postcode	Course_key
1	Lodhi	Mona	22 The Grove, Newport	AB12 3CD	E01
2	Jones	Bob	2 High Street, Stratford	AB6 4PQ	E08
3	Cherry	Colin	59 Acacia Avenue, Brompton	AB2 12ZY	E02
4	Cherry	Colin	13 The Limes, Leighton	XY6 7LR	E05
5	Edwards	Delia	40 Eldon Court, Hampton	XY12 4TK	E02

You can see that Table 7 now has a new field, for the course key. This new field links records in Table 7 to those in Table 3, and lets us see enrolments at a glance. No joining table is needed.

The additional key in Table 7 (the course code) is known as a foreign key. Using a foreign key has enabled us to dispense with the joining table, but only because the relationship between students and courses is no longer many-to-many. When the relationship between entities is many-to-many, a joining table is needed.

Activity 11 (self-assessment)

Suppose Table 5 is to be normalised into separate tables for the ‘Committee’ entity and the ‘Member’ entity.

Why is a joining table needed?
Construct the joining table, using Committee as one key and Member as the other.

Answer

A joining table is required because the relationship between ‘Committee’ and ‘Member’ is many-to-many. (A committee has several members, and each member can be on more than one committee.)
See Table 8.

Table 8 Joining table for Activity 11

Committee	Member
Planning	Jones
Planning	Patel
Planning	Robinson
Recreation	Jones
Recreation	Smith
Education	Patel
Education	Robinson
Education	Smith

This is as far as we shall go in constructing relational databases. The important point to appreciate from this brief introduction to the topic is that even a fairly simple example has called for a careful analysis of the nature of the information and how it is related. Many large-scale information systems succeed or fail on the quality of the analysis, and the quality of the design that follows from the analysis.

Some of the processes of database construction can be done automatically. For instance, if you construct a table like Table 1 in Microsoft Access, the program itself can make a reasonable attempt at creating entity tables and joining tables for you. However, for large-scale information systems, such as those involved in e-government, there is no substitute for a careful study of the nature of the information, its relationships, and its uses.

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3.4 Using a query language

The Open University — Mon, 18 Jul 2011 08:33:16 GMT

When you search a large website for information, for instance when you search a large e-government site, very often, behind the scenes, a large relational database is being searched. I mentioned earlier the use of SQL as a way of extracting information from a database. Depending on the system being used, your enquiry may be converted into an SQL query, and this finds the information you need. For example, suppose we wanted to find the family names of all people enrolled on the digital photography course (E02) in the last section. Below is an SQL query to find this information. (There are other ways to construct this query using SQL.)

SELECT FAMILY_NAME

FROM TABLE_2 JOIN TABLE_4 ON TABLE_2.STUDENT_KEY=TABLE_4.STUDENT_KEY

WHERE COURSE_CODE=‘E02’

I will briefly explain how the query works. It is based on the idea of merging Tables 2 and 4 (‘Table_2 join Table_4’), subject to certain constraints. One constraint is that the student_keys must be equal (‘On Table_2.Student key=Table_4.Student_key’). In effect, the merged table is like Table 2, but with an extra column giving the course codes for each student. However, the only records included in this table are those for which the course code is E02, as specified in the condition ‘Where course_code=‘E02’’. The first instruction (‘select family_name’) retrieves the required information from this joint table.

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3.5 Other kinds of data

The Open University — Mon, 18 Jul 2011 08:33:16 GMT

All the data we have had so far in the database has been text or numbers. I have mentioned that another type of data might be dates. Modern databases, however, can store other kinds of data than text, numbers and dates. They can also store graphics, moving pictures and sounds.

Activity 12 (exploratory)

What complications might there be when incorporating pictures, sound clips and moving pictures in a database?

Discussion

The following three points occur to me:

Files for pictures, sound clips, etc., are often very big. This is not an insuperable problem, but often, rather than incorporate the file in the database, a link to it is incorporated. This is a pointer to where the file might be found.

Users of the database need to be able to view the data. This is not usually a problem if the data is text, numbers or dates, but needs special provision if it is not. Imaging and audio software might need to be incorporated, therefore, in the database software so that users can see graphics or hear sound.

Users of databases need to be able to search for data. With graphics, sound or video files it is usual to store associated descriptive text (or keywords) along with the file so that a search can find it.

A common example of a database that incorporates non-text and non-numerical data is the photograph-album software that comes with many digital cameras. This enables the user to archive their digital photographs, along with textual data, such as title, date, camera settings and so on. On a bigger scale, databases relating to large groups of individuals, such as library users, employees, criminals and so on, increasingly include such non-text items as photographs, vocal recordings, fingerprints and iris scans. These are examples of biometric data, which we shall look at in the next section. Biometric data is used to help identification – photographs being perhaps the most obvious example.

Activity 13 (self-assessment)

What are the two main types of database?
What is an entity?
What is the purpose of a joining table?

Answer

Flat databases and relational databases.
An entity is a distinct thing for which we wish to store information.
A joining table is a means of relating entities by relating the records of each table through their keys.

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3.6 Viewing the data

The Open University — Mon, 18 Jul 2011 08:33:16 GMT

Reverting to the relational database we constructed in Section 3.3, you might wonder what, from the user's point of view, has been gained by creating separate tables for the students and courses. With Table 1 you could see at a glance who was studying what. In the relational database it was hard to see the same information. However, with databases (relational and flat) the user does not normally view tables directly. Generally data is viewed in a ‘form’, which is a specially designed interface between the user and the database. Figure 1 is an example.

View larger image

Figure 1 Form view of a database

Long description

The rectangular boxes in Figure 1 show the field values of a particular record or set of records. The user can scroll or jump forwards and backwards though the records, or search on any field for a particular piece of data.

Not all the fields of a database need be shown in the form; and some of the displayed data might be extracted from the database through the use of a query language, such as SQL, though generally the user is insulated from the complexities of the query language. The fields in Figure 1 are labelled for ease of identification, for example ‘Course centre postcode’, ‘Start date’, and so on. These labels are design features of the form; they need not be the same as the entity names or attribute names. The arrangement of the fields in the form can easily be redesigned for ease of use without affecting the underlying data in the tables. In fact, there are few limits to the way data can be viewed in a form view.

Another way to view data is for it to be ‘rendered’ for viewing on a web browser. This is a bit like a form view, except that the form is created by HTML code. For example, when you look at your Open University personal web page, you are viewing data that is taken from large relational databases, but rendered for viewing on a web browser. The same goes for some of the interactive facilities you would have seen on some of the government websites.

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3.7 Databases and XML

The Open University — Mon, 18 Jul 2011 08:33:16 GMT

In Table 1, it was easy to see which pieces of data belonged to which fields, where the records began and ended, and so on. The tabular layout enabled us to see at a glance the salient features. If you wanted to find a particular name in a table, you ran your eye down the ‘name’ field. It is a different matter for a computer. How does a computer ‘know’ which pieces of data belong to which field? How does it look in the right places? The data on the hard drive or in the RAM is not even arranged in a tabular way.

For a human user, a tabular layout gives a structure to the data. When data is structured, it is clear where a piece of data begins and ends, and which record and field a piece of data belongs to. For the computer to be able to work in a similar way with data, the data needs to be structured in a way that the computer (or rather, the program) can interpret. Different database systems have different ways of recording where data begins and ends, and which fields the data belongs to. Often additional data is incorporated into the database for this kind of ‘housekeeping’, but it is hidden from the user. This extra data is used by the program to encode the structure of the data. Word-processor files similarly contain data that is hidden from the user – for instance, instructions to display certain pieces of text bold and other pieces as italic.

Different database programs demarcate the structure of data in different ways, and this has proved to be a major problem in the e-government projects of many countries. Consider, for instance, accessing a government portal in order to use a particular service. You might have to log on, supplying a username and password. Behind the scenes, verification processes will check these and either allow you to proceed or not. You might then move on to other parts of the system to investigate, for example, your entitlement to benefits or to check tax liability.

Although you may have entered the e-government website via a single portal, behind the scenes the data required for these activities will typically be held in several different proprietary database systems. This is because of the long history of piecemeal implementation of databases in entra and local government. Typically there will be no common standard for coding the data fields in these databases. For example, in one system addresses might have fields with names such as House umber, Streetname, Town, City, Postcode and so on. Another system might have Address1, Address2, Address3 instead. This is an example of the ‘legacy problem’. In many cases it is too expensive to replace these diverse systems with new, integrated systems operating to common standards. Somehow the older systems have to be incorporated into the newer e-government systems and have to be able to work together with them. A vital tool for enabling these diverse systems to work together has been XML, or extensible Markup Language, which I will briefly discuss.

The idea of marking up goes back to pre-computer printing technology The (human) printer would be supplied with a typescript of the document to be printed. The document would be ‘marked up’ with handwritten tags or labels (Figure 2).

View larger image

Figure 2 Use of tags for marking up

Long description

The tags were coded instructions for particular fonts and sizes, and an accompanying sheet explained what they represented. The meaning of the tags would change from typescript to typescript; the tags did not have fixed meanings that applied to all typescripts the printer would work on.

Tagging is a way of keeping appearance and content separate. In Figure 2, the typescript is the content, and the appearance (how the text should look on the page) is embodied in the tagging. XML uses this idea of tagging to indicate the form or structure. As with the print markup, XML tags have no fixed meaning, and so any particular XML document needs an accompanying definition of what the tags represent. This is usually done in a schema. Although to some extent XML resembles HTML, the need for a schema in connection with XML documents is a crucial difference. In HTML there is no schema, and the meanings of tags are set down in a standard.

One difference between XML coding and the old style of print mark-up is the embedding of XML tags within the content of the document itself, rather than their being in a reserved part of the document. (In the case of the print mark-up, the reserved area is the margins.)

Activity 14 (exploratory)

What safeguard is needed if tags are embedded in the text itself?

Discussion

The most important safeguard is that the tag should not be interpreted as part of the content of the document. This is usually done by surrounding the tags with special characters (or symbols). XML uses angle brackets, < and >, as HTML does. Notice that in the print mark-up, the tags are encircled as a further aid to keeping them separate from the content.

As an example of XML in practice, Figure 3 shows a small StarOffice spreadsheet. (StarOffice uses XML coding in all its files.)

Figure 3 StarOffice spreadsheet

Long description

Below is a small part of the XML file for this table. Don't worry about trying to understand it. I have picked out some of the data items from Figure 3 in bold. Notice how little of this extract is content, and this extract is just a small part of the entire file.

<table:table-row table:style-name=“ro1”>

<table:table-cell><text:p>Animal</text:p></table:table-cell>

<table:table-cell><text:p>Number</text:p></table:table-cell>

<table:table-cell table:style-name=“Default”><text:p>Date</text:p></table:table-cell>

</table:table-row>

<table:table-row table:style-name=“ro1”>

<table:table-cell><text:p>Cat</text:p></table:table-cell>

<table:table-cell table:value-type=“float” table:value=“21”><text:p>21</text:p></table:table-cell>

<table:table-cell table:value-type=“date” table:date-value=“1953-05-01”><text:p>01/05/53</text:p></table:table-cell>

</table:table-row>

<table:table-row table:style-name=“ro1”><table:table-cell><text:p>Dog</text:p></table:table-cell>

<table:table-cell table:value-type=“float” table:value=“75”><text:p>75</text:px/table:table-cell>

<table:table-cell table:value-type=“date” table:date-value=“1964-07-25”><text:p>25/07/64</text:p></table:table-cell>

From what you have learned about HTML you will recognise the use of symbols like < > and / to distinguish parts of the file that deal with layout from parts that deal with content. HTML and XML have both evolved from an earlier mark-up language called SGML (Standard Generalized Markup Language), devised for use with print documents.

Many proprietary ICT systems use coding to keep information about appearance and content separate. Two things make XML different from proprietary equivalents:

It is an open standard. Its openness means that it is not owned by any particular company.
It is extremely adaptable to new ways of distributing and presenting information.

These two factors make XML invaluable as a common language for exchanging structured data. However, by itself XML does not solve thel legacy problem. In addition, there need to be various types of middleware to translate legacy data into XML, and to translate in the opposite direction. (Middleware is a general name for software that canl enable separate systems to work together.) Middleware is specific tol particular systems, so solving the legacy problem also involves thel appropriate middleware. This might mean buying it, but in some casesl it means creating it specially.

XML is widely used where different systems need to operate together, and not just legacy systems. For instance, through the adoption of standard schemas for data exchange, banks can swap information easily among themselves, even though their information systems are very different. Many other types of business use XML to allow for standardised ways of transmitting information. XML has also been influential in the growth of web services. Web services are self-contained reusable programs that are components of online services. Examples are authentication of identity, currency conversion, shipping processing, etc. The programs that perform web services are self-contained units, and can be incorporated directly into a more complex online service.

These services need to be able to work on many different platforms, that is, in many different computing environments, with many different programming languages. The open nature of the XML standard has allowed this to happen. XML is also increasingly used ‘behind the scenes’ in word-processing documents, spreadsheets, databases and online documents and forms.

The impact of XML on information exchange and online provision of services has been enormous and will almost certainly continue to grow. Bisson (2005) wrote:

Tomorrow's XML will also be much more visible in the foreground of computing. Computer desktops will become canvases for active documents that mix XML data and formatting information – and include links to web services. Your online tax return will be a document that looks like the paper forms the Inland Revenue sends, but it will be able to work with online calculation services, before delivering XML data directly into the Inland Revenue systems (and automatically transferring your refund into your bank account).

The development of XML has been very timely for the e-government project because it has allowed incompatible systems to work together. However, XML is only part of a much bigger picture. In the UK, the government has set up an e-GIF (e-government interoperability framework) initiative, which is a set of compulsory standards for the public sector of the UK. These standards define the way that data should be structured and accessed. For instance, the e-Gif framework specifies the use of web browsers for viewing data, the use of XML for integrating data, the use of internet and Web protocols, and so on. Systems that are ‘e-Gif compliant’ (i.e. which conform to the e-Gif specifications) should be able to communicate between themselves. A European e-Gif system is under development at the time of writing.

The increasing ease of transfer of data is practical and convenient. But is it always in the best interest of the people whose data is held? People who have investigated the data held about them by, for instance, credit card companies, have often been surprised at the amount of data held, and questioned whether much of it was relevant to the business of credit card companies. In the context of e-government a particular concern is the ease of transfer of data from one government department to another, so that, for instance, a person's medical records or tax record might be viewable by other departments. Another concern is that personal information could be made available to private companies. With the contracting to private companies of work formerly done by government departments, private companies often need access to the information held in government databases.

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3.8 Data modelling and databases

The Open University — Mon, 18 Jul 2011 08:33:16 GMT

The subject of databases becomes very complex with deeper study. This is not so much because database software requires great skill to make it do what is needed, but because database design begins with a deep understanding and analysis of what the entities and attributes are, and the relationships between entities. This is data modelling, and very little of it has anything to do with computers; rather it is much more about studying carefully how organisations work, how information is acquired and used, who uses it and how, and so on.

Databases probably impinge on our lives more than we realise. As we have seen, they underlie many websites of any complexity, but they also underlie great swathes of the e-government project, as well as billing systems from utility companies, booking systems for holidays, personal records held by employers, banks, credit card companies, and so on. The list of applications of databases goes on and on. In addition, databases are essential components of modern telecommunications, for instance in the routing of data packets on the internet. They are also essential to electronic systems of personal identification, which is what I will look at next.

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4.1 Data and biometric data

The Open University — Mon, 18 Jul 2011 08:33:16 GMT

Developing alongside the various e-government projects around the world are many biometric systems for authenticating identity. Governments have traditionally had a stake in the authentication of a citizen's identity through issuing passports, driving licences and other so-called identity documents. However, this is yet another area where ICTs are having a transforming effect, perhaps not to everyone's liking:

At America's insistence, passports are about to get their biggest overhaul since they were introduced. They are to be fitted with computer chips that have been loaded with digital photographs of the bearer (so that the process of comparing the face on the passport with the face on the person can be automated), digitised fingerprints and even scans of the bearer's irises, which are as unique to people as their fingerprints.
A sensible precaution in a dangerous world, perhaps. But there is cause for concern. For one thing, the data on these chips will be readable remotely, without the bearer knowing. And – again at America's insistence – those data will not be encrypted, so anybody with a suitable reader, be they official, commercial, criminal or terrorist, will be able to check a passport holder's details. To make matters worse, biometric technology – as systems capable of recognising fingerprints, irises and faces are known – is still less than reliable, and so when it is supposed to work, at airports for example, it may not.
The Economist (2005)

In this section we shall look at some of the techniques and issues related to the authentication of identity using biometric data.

Biometric data is derived from distinctive bodily features. Examples are fingerprints, photographs, iris patterns, and so on. ‘Biometric data’ also covers data derived from characteristic behaviours or gestures, for example signatures or vocal characteristics. Converting this data to digital form allows it to be processed automatically by computers. This is a distinct change from older methods of identification which depended on a good deal of human inspection (for instance, visual inspection of fingerprints). Biometric data is increasingly incorporated into passports, driving licences and other identity documents.

Whatever method of identification is used, comparison of one piece of data with other data is involved. For instance, in criminal investigations, fingerprints collected from the scene of a crime are checked against records of fingerprints from known criminals.

For an identification system based on data comparison to work, there must be authoritative samples of data, from known individuals, to compare with. The bank of fingerprints held by the police is a collection of such data. But two specimens of data from the same person are hardly ever identical – for instance, the signature I write on a cheque is not identical to the one on my cheque card. Whether my cheque card confirms the signature on my cheque is a matter of judgement.

In the following pages, I would like you to keep in mind these two essential components of identification systems:

Authentic data, known to be associated uniquely with a particular individual, is required for comparison.
Reliable methods are required for comparing pieces of data and for deciding whether they are from the same person.

We shall look more closely at the implications of these requirements shortly, but first I should say a little more about what I mean by ‘data’ in the context of identification systems.

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4.2 Data for identification

The Open University — Mon, 18 Jul 2011 08:33:16 GMT

I have already mentioned signatures, photographs and fingerprints as examples of the kinds of data that have been used for authenticating a person's identity. Many other types of data have been used or suggested. DNA is widely used, but mostly in criminal investigations. Iris recognition, which relies on distinctive patterns in the coloured part of the eye, is another technique. Figure 4 shows a collage of iris patterns.

Figure 4 Iris patterns (courtesy of Dr John Daugman, Cambridge University)

Long description

Whatever type of personal data is used, it needs to be unique for each individual. The fingerprinting system depends on everyone having different fingerprints. Facial recognition depends on no two faces being the same. Iris patterns appear to be unique to each individual. In fact, the patterns in the left and right eyes of the same individual are different, and identical twins have different iris patterns.

Activity 15 (exploratory)

What advantages for identification does biometric data have over non-biometric data such as names and addresses, passwords, etc?

Discussion

Two advantages occur to me. The first is that everyone's biometric data is (or is believed to be) unique, whereas non-biometric data sometimes cannot be guaranteed to be unique. The second is that biometric data should be harder to steal than non-biometric data.

For many decades the only biometric data that was routinely used to authenticate someone's identity was photographic data. For instance, passports and membership cards have traditionally had photographs. However, the development of ICT has opened up possibilities for using other kinds of data. With biometric data in a digital form, comparison of data becomes a mathematical operation that can be computerised, rather than requiring human checking. I can illustrate this with a highly simplified example.

Suppose a piece of biometric data consists of a person's numerical scores on three different criteria (maybe eye separation, eye size and eye colour). One person's data might consist of the binary equivalent of the three numbers 24, 7 and 125, where each number represents the value of a different physical property. Another person's data might be 26, 6 and 122. Each number in the second set of data is close to the corresponding number in the first set. A computer could calculate how close this second set of data was to the first by comparing each of the three numbers in turn. A preset threshold can be applied such that if the two sets of data are closer than the threshold they are judged to be a match. If they are not closer than the threshold, they are not a match. Note that although the comparison can be computerised, the threshold itself is set by a human.

Biometric data is not immune from theft or forgery. There are cases of people making a cast of someone else's finger and using it to gain access to systems that use fingerprint recognition (Bowcott, 2004). A disadvantage of biometric data is the difficulty of restoring security once it has been breached. For instance, if a user's fingerprint has been copied, a replacement fingerprint cannot be offered, whereas a replacement password can easily be issued.

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4.3 Identification systems

The Open University — Mon, 18 Jul 2011 08:33:16 GMT

At the time of writing, biometric identification is not in widespread use. although that situation is likely to change. There are, however, a few schemes which have been used, and I would like to look at two of these now. The first is the experimental EyeTicket JetStream iris-recognition system that was used for passport-free immigration control at Heathrow airport in the UK in 2002. The scheme, which ran for about six months, was used only on travellers who had enrolled in it. To enrol, applicants had iris scans taken of their eyes. Figure 5 shows enrolment in a similar system at Schiphol airport.

Figure 5 Enrolment in the iris-recognition system at Schiphol airport, Amsterdam. The woman at the back is having her iris scanned. The woman at the front enters the data into a database (courtesy of Dr John Daugman, Cambridge University)

Long description

In the Heathrow scheme, and many others, the biometric data acquired during enrolment was stored as a template in a database of enrolled users. The template in this case was not a digital photograph of the eye, but a digital representation of data from the iris scan. An analogy would be a file that recorded eye colour, separation of eyes, diameter of iris, and so on. However, in the case of iris scans the data relates to the patterns of markings shown in Figure 4. The template can be quite small in data terms. In one system, the iris data in the template has a size of 256 bytes. In other systems, however, templates are digital photographs of the eyes.

Enrolment in the Heathrow scheme involved not just taking a scan from the applicant and entering it into the database, but also checking whether this person's scan matched any of the templates already in the database.

Activity 16 (Exploratory)

Why might the applicant's scan have matched a template already in the database? More than one answer is possible.

Discussion

There are two possibilities to account for the person's biometric data matching an already existing template.

The applicant's scan was similar enough to someone else's template to be within the threshold. This is always possible, although ideally it will be rare. (You will see why mismatching is possible shortly.)
The applicant was trying to enrol a second time, and matched their already existing template.

In the first comment on Activity 16, the applicant is innocent of any subterfuge. In the second case, the applicant might or might not be innocent. For instance, the applicant might have forgotten their earlier enrolment, or might be enrolling under a different name having legitimately changed their name (for example through a change of marital status). On the other hand, the applicant might be dishonestly trying to enrol a second time under a different name. This last possibility is a particular concern with the issuing of identity cards, which in the UK will also serve as entitlement cards for benefits and other services.

In the Heathrow experimental scheme, if the enrolment happened without complications, then on subsequent visits to Heathrow the traveller would look into a scanner at immigration control. This would take an iris scan, which would be compared with all the templates in the database. If there was a match with one of the templates, then the person was regarded as having been identified, and passed through without needing to show a passport.

Similar systems to the Heathrow one are used at several airports to ensure that only authorised staff can get to restricted parts of the airport. In Japan they are also used for access control in some residential apartment blocks. At the entrance, the resident looks into a scanner, and if their scan matches a template in a database they are allowed in. A common feature of all identification systems is this process of taking a sample of data when authentication is needed and comparing it with an entire database of templates.

A rather different type of identification system is used in the United Arab Emirates. All inward travellers to the country at all entry points have iris scans taken with machines like that shown in Figure 6.

Figure 6 Iris-recognition system in the United Arab Emirates. In the photograph, the scanner is obscured by the man's head

Long description

These scans are checked against templates for a ‘watchlist’ held on a central database. The watchlist consists of about 400 000 individuals who, for various reasons, are to be denied entry. If no match is found, then the traveller is allowed through and completes the normal immigration procedures.

Activity 17 (exploratory)

In the Heathrow and United Arab Emirates systems, a match between the traveller's data and a template in the database had different outcomes. How did the outcomes differ?

Discussion

In the Heathrow experimental system, a match with a template meant the traveller could proceed, whereas in the United Emirates System a match meant the traveller could not proceed.

The difference mentioned in the last activity indicates that identification systems can be used in two different ways. In the Heathrow system, the assumption was that most checks result in a match, whereas in the United Arab Emirates system the presumption is that most checks do not result in a match. This difference is sometimes expressed in terms of positive identification and negative identification Positive identification is a check on whether someone is a member of a particular set of people. Negative identification is a check on whether someone is not a member of a set of people.

What characterises an identification system is that it checks whether a particular individual is known to the system. This is the check that was made in both the Heathrow experimental system and the United Arab Emirates system. An identification system does not necessarily identify the person. However, it is not difficult in principle to extend identification systems so that they do establish a person's identity. Suppose you have templates for every citizen of a country in a database, together with personal data about the people the templates were taken from. This system could theoretically act as a national identification scheme. At any point where identification was required, the person could supply a sample of biometric data (perhaps by looking into a scanner), and this would be checked against the entire national database. If there was a match, then the person's name and address could be shown. Through links to other databases, other personal information could theoretically also be brought up, such as medical records, police records, employment and social security records, and so on. Such a scheme, if it could be made to work, takes us into ethical and political issues, which I will return to later. For the moment, there are questions of feasibility to consider, arising from the problem of so-called false matches.

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4.4 False matches and false non-matches

The Open University — Mon, 18 Jul 2011 08:33:16 GMT

I mentioned earlier that one of the essential components of an identification system was a reliable procedure for comparing data. Ideally, one person's biometric data would never be mistaken for another's, and one person's biometric data would always match another sample from the same person. Unfortunately such perfection cannot be achieved in practice. Errors happen because samples of biometric data taken from someone on different occasions are almost certain to be different, just as two specimens of my signature are different. This means that establishing someone's identity by looking for an exact match between biometric samples is not possible.

The practical solution is to look for a certain level of similarity rather than exact sameness. To count as a match, two samples of biometric data need to be sufficiently similar rather than identical. What are the implications of this fact? We can get an insight into their implications by thinking about Figure 7. The two faces represent samples of biometric data, and the arrow represents a comparison. Clearly the samples are different, but are they from the same person?

Let us suppose that these samples are from the same person. To be fairly sure of getting a ‘Yes’ verdict in the comparison, we should set the threshold of similarity at a fairly low level. That is, our comparison system should be quite tolerant of differences between samples of biometric data. That increases the likelihood of the right verdict: ‘Yes. These are from the same person.’

Figure 7 Comparison of biometric data

Long description

But suppose the two samples of data in Figure 7 are from different people. If the comparison is tolerant of differences, these samples will be judged to be from the same person, which is the wrong answer (in this case). To increase the likelihood of the correct verdict when the samples are from different people, the comparison needs to be less tolerant of differences.

As you can see, there are conflicting requirements here. To ensure that samples of data from the same person match we need a fairly relaxed criterion of similarity. But to ensure that difference is detected, we need a strict criterion.

These two types of error are known as false match and false non-match. They are illustrated in Figure 8.

A false match is when two pieces of biometric data from different people are judged to be from the same person, as in Figure 8(a). This type of error is sometimes called a false accept. It results from a comparison that is too tolerant of differences.

A false non-match is when two pieces of biometric data from the same person are judged to be from different people, as in Figure 8(b). This type of error is sometimes called a false reject. It results from a comparison that is too intolerant of differences.

Activity 18 (self-assessment)

Which type of error is increased by relaxing the matching criterion, and why?
Which type of error is increased by making the matching criterion stricter, and why?

Answer

False match. Relaxing the matching criterion means making the matching process more tolerant of difference. This increases the likelihood that biometric data from different people will be judged to be from the same person.
False non-match. Making the matching criterion stricter means that the comparison is less tolerant of difference. This means that we are more likely to decide that samples of data from the same person are from different people.

Figure 8 Two types of matching error

Long description

False matches and false non-matches are not caused by the use of ICT-based systems or by the use of biometric data. They can happen when any type of data is assessed for similarity by any type of inspector – human or otherwise.

The performance of biometric systems is gauged by various statistics. One of these statistics is the false match rate. The following section looks at some typical false match rates.

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4.5 Typical false match rates

The Open University — Mon, 18 Jul 2011 08:33:16 GMT

A false match rate is expressed as a statistic such as ‘1 in 1000’. A rate of 1 in 1000 means that if a sample of biometric data is compared with random selections of other data, a false match occurs, on average, once every 1000 comparisons. False match rates vary widely between different biometric systems. The following figures are taken from Mansfield and Rejman-Greene (2003).

Using good-quality fingerprints, a false match rate for single prints can be around 1 in 100,000. This rate can be improved by using more than one finger. Low-quality prints give worse rates.

Face recognition gives a false match rate of around 1 in 1000.

For single-eye iris recognition, Mansfield and Rejman-Greene (2003) quote a false-match rate of 1 in 1,000,000. Using two eyes improves the rate considerably.

These rates do not allow you to predict how many false matches there will be in any single small-scale test. For instance, a system with a false match rate of 1 in 1000 when tried on a group of 10 or 100 people might or might not produce false matches. The outcome is unpredictable. However, with a large group the result becomes more predictable. For instance, a system with a false match rate of 1 in 1000 when tried on a group of 1,000,000 people will produce about 1000 false matches. This figure comes from dividing the group size, 1,000,000, by 1000, which comes from the false match rate of 1 in 1000. However, this method is only an approximate one, and can be used only with large groups. What we mean by ‘large group’ or ‘small group’ depends on the false match statistic. For instance, if the false match rate is 1 in 100, a group size of 10 000 is quite large; but with a false match rate of 1 in 100,000, the same group size of 10,000 is small.

Activity 19 (self-assessment)

The false match rate of a particular biometric system is 1 in 100. A sample of data is compared against 1,000,000 other randomly chosen pieces of data. Approximately how many false matches can we expect?

Answer

Compared to the false match rate of 1 in 100, the group size of 1,000,000 qualifies as large, so we can use the approximate method described above. To find the answer we need to divide 1,000,000 by 100. This gives 10,000. This is approximately the number of false matches we can expect.

The lesson to draw from the last activity is that if the number of comparisons is sufficiently large, then a lot of false matches can result, even if the false match rate appears to be quite low. This needs to be borne in mind when thinking about identification systems for a whole population.

Deciding which biometric system to use is not just a matter of picking the one with the best false match statistics. The figures given above are laboratory figures, and whether the same performance can be obtained in practice, when conditions are not ideal and the participants may be impatient or uncooperative, is another question. Also, there is the question of how a system would work in practice. Would it require people to stop and do something, potentially causing bottlenecks at busy places such as airports, or could it operate on people while they were doing something else, without their being aware that an identity check was being carried out, as with face recognition? Considerations like these play a part in deciding which system to use.

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4.6 False identification

The Open University — Mon, 18 Jul 2011 08:33:16 GMT

If you think back to the Heathrow experimental system and the United Arab Emirates system described earlier, you can see that the false matches and false non-matches open up possibilities for these systems to malfunction. In the Heathrow scheme, a false match could mean that a person who was not enrolled might be allowed through. In the United Arab Emirates scheme, a false non-match might mean that a person who should be stopped is allowed through. These are examples of identification error.

Work through the animation below, then move on to the next Activity. (Click on the link below to view in a separate window.)

Interactive content appears here. Please visit the website to use it.

Activity 20

Work your way through the animation above called Identification and verification. It will take around 15 minutes. The animation reviews the material you have already studied on identifiation, and introduces the concept of verification which you will study shortly.

Discussion

Disc

The animation shows that the rate of false positive identification depends on two things: the false match rate and the size of the database. For example, if a system has a false match rate of 1 in 1000, when used on a database of 1000 (or bigger) it is virtually certain that there will be a false positive identification with someone in the database. Thus, the false positive identification rate in this case approaches 100 per cent (1 in 1), because of the large size of the database. A false positive identification rate of 100 per cent means that every time a sample is checked against an entire database, there is at least one false match somewhere in the comparisons.

Besides reviewing the idea of identification, this has introduced the concept of verification, which we shall come to shortly.

To summarise, false positive identification arises from a false match with a template belonging to someone enrolled in a database, as shown in Figure 9.

The rate at which this happens depends on both the false match rate and the size of the database.

Note that it is possible for a piece of biometric data to falsely match more than one template in the database. It is also possible for a piece of biometric data to correctly match one template, and to falsely match one or more other templates.

View larger image

Figure 9 False positive identification error. The subject's data is tested against the entire database and falsely matches one of the templates

Long description

We have probably all experienced false positive identification error when we see someone we think we know, say ‘Hello’ to them, and then realise it is not the person we thought it was. Something about them looked familiar, but the similarity was deceptive.

False negative identification error arises from failure to match the person with their own template in a database (Figure 10).

When there is false negative identification, it is conceivable that the person's data could falsely match someone else's template. However, this is irrelevant to the meaning of false negative identification, which is strictly about the failure of a person's data to match their own template.

We have probably all experienced false negative identification when we fail to recognise someone we already know, possibly because they have changed their appearance or because we meet them in an unfamiliar context.

View larger image

Figure 10 False negative identification error. The subject's data is tested against the entire database and fails to match the same person's template

Long description

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4.7 Identification errors and the national database

The Open University — Mon, 18 Jul 2011 08:33:16 GMT

The UK identity card scheme, and similar schemes in many other countries, is based on the idea of creating a national identification register. This is a database that will have templates of biometric data from all citizens. In the UK, the proposal is to have a photograph, some fingerprint data and iris scans from each citizen. There will also be other data in the register: name, address, national registration number, and much more besides. Identity cards will be issued only to people who are enrolled in the national identification register. This latter point is crucially important to the system envisaged for the UK.

Much of the controversy about identity cards relates more to this national database of personal data than to the cards themselves. In the next few activities, you will be looking at extracts from an article by Roger Dettmer that looks at the practicalities of creating a national identification register. As you will see, Dettmer is essentially concerned with identification errors, and his observations apply equally to any national-scale identification system.

Click on 'view document' below to read the first part of the article 'Safety in Numbers' (with thanks to R. Dettmer).

View document

Activity 21 (self-assessment)

Read the extract from Dettmer (2004). Note that in this and subsequent extracts you might not be able to understand all the details, but you will probably be able to follow the argument.

Briefly explain why Dettmer sees false negative identification as a security problem, whereas false positive identification is not. Remember that false negative identification is failure to recognise someone already enrolled. False positive identification is misidentifying one person as another.
Why does usability require a low probability of false positive identification?

Answer

False negative identification error enables someone to re-enrol in the system under a new identity, and thereby get a second identity card. This possibly enables fraudulent use of services and is a security problem. False positive identification means (in this context) that an applicant is wrongly thought to have already enrolled. A new identity document will not be issued until the applicant can prove his or her true identity by other means. False positive identification is not a security risk because no new documents are issued until the confusion is resolved.
False positive identification creates extra work for the operators of the system sorting out the misidentification. Therefore a usable system should have a low probability of false positive identification.

Reading technical articles

The Dettmer extract for the last activity was quite short, and perhaps did not cause you undue trouble. The extract in the next activity is longer and might not be so straightforward.

It is easy to get demoralised if you are reading a technical article and find it hard going. If that is how you feel, you are in good company. Very few people find technical articles easy to read, and few experts would expect to be able to understand everything in an article. In fact understanding an article is not an ‘all or nothing’ business. There are degrees of understanding, and for many experienced readers understanding is approached by stages. Very often the first read through is quick, to get a general impression. On the basis of that, there's a decision to be made: Do I persevere, or have I got everything from the article I want to get from it at the moment? If the decision is to persevere, then the next reading is more methodical. One of the jobs on subsequent readings is to isolate the parts that are hardest to understand. You might even need to go to other articles on the same subject to see if they have another approach that makes more sense to you. Alternatively, you might need to spend time thinking about what you have read and rephrasing it in your own words.

I am not expecting you to go looking for other articles on this subject, nor to spend a long time thinking about it. The important point to remember is that it is normal not to understand everything in an article like this. However, here are a few tips to help you.

Generally each paragraph is making one main point, or maybe just a few related points. Try noting these down.
The overall argument is usually carried by the main points, rather than the details, so try to see the story that the main points are telling.
The last one or two paragraphs often contain the major points the author wants to make. It is all right to read those first, and to use that information to fill in some of the parts you are struggling with.
Often if you reread an article after a gap of a day or two, parts that were difficult to understand turn out not to be so difficult after all.

For the next extract, you need to know the meanings of a couple of the terms Dettmer uses. A one-to-one comparison is when you compare one piece of data with another. In this context, those pieces of data are biometric data. A one-to-many comparison is when you compare one piece of data with many others. In this context that might be when you compare a piece of biometric data with all the templates in a database.

Click on 'view document' to read the next extract from the article (with thanks to R. Dettmer).

View document

Activity 22 (self-assessment)

Now read the second extract from Dettmer (2004), and answer the following question: Why does Dettmer say that a biometric identity system will need to be based on taking iris scans from both eyes, or fingerprints from eight fingers?

Answer

Iris scans from a single eye, or fingerprints from a few fingers, do not give a sufficiently low false match rate. Using both eyes, or more fingers, improves the false match rate to a suitable value for a practical system.

Before we look at a final extract from Dettmer, I want to make a short detour into verification. This is because documents such as identity cards, passports, driving licences and the like are, strictly speaking, for verification of identity rather than for identification. Increasingly these documents have biometric data in memory chips incorporated in the document.

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4.8 Verification

The Open University — Mon, 18 Jul 2011 08:33:16 GMT

You will, perhaps, by now be getting a sense of the challenge of setting up an identification system on a national scale. However, for many routine purposes, establishing who a person is from an entire population of possibilities is not what is required. Instead what is required is confirmation that the person is who they claim to be. This is verification. An example of verification happens when you collect a parcel from a depot. You are sometimes asked to show your driving licence, passport or other suitable document. This document verifies your identity.

Verification, like identification, involves a comparison of data, at least when done properly. If I sign for the parcel when I collect it, my signature should be checked against the one in the verification document. Alternatively, if the verification document has a photograph of me, the person issuing the parcel should check me against the photograph.

What distinguishes verification from identification is the number of checks made. In identification, data I supply (or which is taken from me) is checked against an entire database of templates. With verification, my data is checked only against data in the verification document. To use the terms you have already met, identification involves one-to-many checking, whereas verification involves one-to-one checking.

Because verification involves just a single comparison, it offers some advantages over identification. One advantage is that a biometric template can be stored in the verification document itself, in a machine-readable chip. The Schiphol airport system shown in Figure 5 uses this method. Travellers who enrol in the system receive a membership card containing a memory chip. The chip holds the member's biometric template. When passing through the airport, the traveller puts the card into a reader and stands in front of an iris scanner. If the scan matches the template on the card, the traveller passes through immigration control without further formalities.

Another advantage of verification over identification relates to false positive identification. In identification, biometric data has to be checked against every template in the database. The large size of a national database can make false identification quite likely. However, in verification there is only a single check – against the template in the verification document. In fact, in verification we are much more likely to be concerned with false non-matches than with false matches. For example, an enrolled traveller at Schiphol airport would be highly inconvenienced if his or her iris scan did not match the template on the chip. This is a false non-match.

Naturally verification is only as reliable as the document used for verification. As the extracts from Dettmer's article have shown, enrolling users in the proposed UK national identity card scheme requires that the applicant be checked against an entire database of previous applicants before the card can be issued. In other words, enrolment depends on an identification system. Only when an applicant has been successfully checked against the entire database is the verification document issued. This feature distinguishes the UK identity card system from those of some other countries.

Click on 'view document' to read the final extract from Dettmer's article (with thanks to R. Dettmer).

View document

Activity 23 (self-assessment)

Now read the final extract from Dettmer (2004), and answer the following question.

Dettmer foresees problems in setting up a national identity card scheme. Does he see these problems as relating to identification or to verification? Illustrate your answer with one or two short quotations. (There is no need to supply references for your quotations.)

Answer

The problems Dettmer mentions nearly all relate to setting up a national database for an identification system. For instance, he mentions uncertainty over ‘how long it will take to enrol users in a real system’ and ‘what percentage of the population will be unable to travel to their local biometric registration centre’. He says very little about the use of the card for verification.

Dettmer's anxieties, as revealed in the article, relate to the practicalities of the system. Will there be so many identification errors as to make it unworkable and undermine the public's trust? Can people be enrolled fast enough? And so on. However, for many other critics, anxiety is based much more on the principles than on the practicalities. I shall look at some of these concerns now.

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4.9 Ethical, social and political aspects

The Open University — Mon, 18 Jul 2011 08:33:16 GMT

The introduction of identity cards has proved controversial in several countries, for example France (where identity papers have long been a requirement) and Australia. Generally the issues have related to the questions like: ‘What are these cards actually for?’, ‘Whose interests do they serve?’ and ‘What use will be made of the underlying database of identity data?’ Opponents of identity schemes have pointed out that totalitarian regimes have always found identity systems very useful – Nazi Germany and South Africa under apartheid being frequently cited. Even if a present-day government is trustworthy, what assurance is there that a future government will not abuse an identification system? Debates in this field are thus as much ethical, political and social issues as they are technical.

Ethical, political and social issues

Ethical, political and social issues differ in many ways from purely scientific or technical ones. With purely scientific and technical disagreements, there is usually a route to a solution that is agreed on by the disagreeing parties. Thus, although all parties may be convinced of their rightness, they can usually agree on what would be required to settle the dispute. For instance, they might agree that performing a particular experiment or building a prototype device would settle the argument. Behind this ‘agreed route’ idea is the notion that accumulating more facts, or evidence or data will settle the dispute. (In the event, this new data might not settle the disagreement, but the parties will nevertheless agree that this is the way disagreements are settled.)

Ethical, political and social disputes, in contrast, have a different character. With them there is usually no agreed route to a resolution. Although the parties in the dispute may cite data and facts to support their positions, there is not likely to be any crucial evidence that will settle the dispute. In fact, the basis of the dispute often relates to the significance of factual evidence, for instance, whether a particular fact is more or less significant than another. In other words, the debate is about the value that should be attached to factual data.

In technology, issues often arise that inextricably mix science, ethics, politics and social questions. Biometric identification is a good example, but there are many more. As you have seen, there are concerns about gathering personal information about citizens and about the uses such information might be put to. These are ethical issues. Underlying them are questions of rightness or wrongness in a moral sense, rather than in a scientific or technical sense.

You have also seen that there are concerns about whether the state should be able to do certain things, such as compelling citizens to participate in an identification scheme. Questions such as these, which relate to the holding and exercising of power, are examples of political issues.

Finally, as you have seen, there are concerns about the type of society that might result from national (and international) identity schemes. Will some sections of society be disadvantaged relative to others, and will individual liberty be infringed unacceptably? These are examples of social questions, as they relate to thel organisation and running of society.

Distinguishing between the technical aspects and the ethical, political and social aspects of an issue is often not easy. To help to clarify the distinction, it can be useful to think how a dispute could be resolved. If there is a route based on factual data, then it is probably a technical matter. If there is no clear route involving factual data, then there are probably ethical, political and social aspects. For instance, deciding how many fingers need to be used to achieve a particular performance level in a fingerprint identification system looks like a technical matter; but deciding whether national fingerprint data should be made available to the police does not. Even purely technical matters, though, often need to be seen within a larger ethical, political or social context. For instance, a technical question about identification might have very different implications within a totalitarian regime compared with a tolerant regime.

In this section I am going to look briefly at some of the issues in a UK context, although they are not confined to the UK. I am drawing heavily on an article by Dempsey (2005) for this section although I am not quoting him.

Dempsey (2005) points out that in the UK, government arguments for an identification scheme have shifted. At one time identity cards were promoted as part of the campaign against terrorism. This argument has tended to be played down in favour of arguments about reducing benefits fraud. It is claimed that the careful checking of identity that precedes the issuing of a card will make it harder for fraudsters to make multiple claims with different identities. Commentators have questioned both of these arguments. Unless suspected terrorists are on a watch list, it is hard to see how identity cards can thwart them. Furthermore, many authorities have pointed out that benefit fraud usually results from dishonest declaration of income by the fraudster. The fraudster's identity is usually not false, so the usefulness of an identity card looks questionable in this case too. Other critics have pointed out that forged identity cards will almost certainly be available to anyone with the time and money to acquire them, so an identity card system could lead to a false sense of security.

There is certainly a case to be made for the practical usefulness of identity cards. For many low-level verification tasks, UK citizens currently have to use passports and driving licences in the absence of anything more suitable. This suggests a need for some sort of identity document. Many critics worry, however, that cards will come to be required for all sorts of activities that have not needed them traditionally, such as booking a hotel or buying travel tickets. This might seem no more than a nuisance, but many people who are not criminals nevertheless have good reasons to want their true identity kept secret (for instance, if they have fled from abusive domestic circumstances). Life for them would be more difficult. Criminals, on the other hand, who will always be able to get forged cards, will hardly be inconvenienced.

Although the controversy over identification schemes is usually expressed in terms of identity cards, what is at issue is often not so much the cards themselves as the national database, or national identity register, that would underpin the scheme. For many objectors, the creation of a large database containing everyone's photographs, fingerprints and other personal data looks like an erosion of traditional liberties. Hitherto, the only people who have had their fingerprints routinely collected have been criminals. Does collecting biometric data from everyone turn them, potentially, into suspects?

The creation of a national identity register could be argued to be consistent with ‘modernisation of government’ – the justification for so much of the e-government project. Almost any large business nowadays gathers information on its customers and stores it in a database. Compiling information on customers is part of the modern way of doing business. Why should it be different for a government? Managing a country could certainly be much simpler and more efficient if accurate, up-to-date information on the population was available all the time from a national database, rather than only intermittently via periodic censuses.

The convenience and usefulness provided by a national database, however, would not be confined to government. Many private organisations would find access to that kind of information attractive, and might be willing to pay for it. Critics of the identity card scheme suspect that information from the national identification register would find its way into private hands.

Other anxieties centre on the blurred distinction between identification and surveillance. It would, for instance, be possible for a facial-recognition system to be used in conjunction with surveillance cameras, so that a particular individual's movements could be automatically tracked in an area surveyed by cameras. Dempsey (2005) records that traffic cameras from the UK were used for surveillance of student demonstrations in Tiananmen Square in Beijing, China, in 1989.

Looking to the future, it looks likely that identification systems in different countries will require some degree of standardisation. Within Europe, for instance, some countries’ identity cards contain only a photograph of the owner and name and address. In some cases the cards are not backed up by a national database of biometric data.

My final point relates to cost. A national-scale identification system will be expensive. A UK identity card scheme, for instance, would be one of the largest IT projects ever undertaken. If the justification for the system is, say, crime reduction, could a better result be obtained by spending the money in other ways? Many critics of an identity system argue that it could, although the UK scheme is intended to be largely self-financed from the cost of enrolment.

This section has given only a brief coverage of some of the ethical, political and social issues involved with an identity system. However, there is plenty of further material on the Web.

Activity 24 (self-assessment)

Which of the following questions clearly raise ethical, political or social issues, and why?

Which biometric system has the best false match rate?
What information should be held on an identity card?
How much should citizens be charged for their identity cards in order to cover the cost of setting it up?
Which type of data chip on an identity document is most easily read remotely?
During enrolment, how should cases of false positive identification best be handled?
On what occasions should citizens be required to identify themselves, and who should have the right to demand identification?

Answer

This can be resolved experimentally, so looks like a technical matter.
It is hard to answer this without asking further questions about what the information will be used for and why. These look like ethical, social and political questions.
This looks like a technical matter. However, if differential pricing is used, deciding how much different categories of people should be charged takes on ethical, political and social aspects.
This looks as though it could be settled by experiment, so it looks like a technical matter.
This does not look as though it could be resolved with a purely factual input, so it has ethical, political and social aspects.
Again, these do not look as though they could be resolved with a purely factual input, so ethical, political and social issues are raised.

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5.1 Introduction

The Open University — Mon, 18 Jul 2011 08:33:16 GMT

The word usability has cropped up a few times already in this unit. In the context of biometric identification, usability referred to the smoothness of enrolment and other tasks associated with setting up an identification system. A system that produced few false matches during enrolment of applicants was described as usable.

Another meaning of usability is related to the ease of use of an interface. Although this meaning of the term is often used in the context of computer interfaces, there is no reason to confine it to computers. The concept of usability applies equally well to the design of tools and implements, or to noticeboards, for example Figure 11.

Figure 11 Noticeboard in a park

Long description

Activity 25 (exploratory)

How would you rate the usability of the noticeboard in Figure 11? If you think it would not be easy to use, what is the cause of the problem or problems?

Discussion

When I came across this sign, I was puzzled for a while, so I did not rate its usability very highly.

All the distances are on the right of the board and aligned. It makes for a consistent style of presentation, so that distances can always be found on the same part of the board (there were other noticeboards like this one in the park). From that point of view the board conforms to generally accepted principles of ‘good design’. However, as a user, my first impression was that the right-hand side of the board related to things to the right of the sign, and the left-hand side of the board related to things to the left of the sign. The arrows seemed to support this view (especially the puzzling second line of the board, which has arrows in both directions).

In the context of e-government, usability is of particular concern because the public is unlikely to adopt the new systems of delivery of services if they are difficult to use.

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5.2 Usability principles

The Open University — Mon, 18 Jul 2011 08:33:16 GMT

Usability as a field of study has grown rapidly with the spread of computers, the Web, mobile phones and other portable ICT devices. Although there are some basic principles of good, usable design, there are no rules that guarantee a good design. In this respect design for usability is like other branches of design, such as industrial design, book design or interior design.

Usability design draws on ideas from psychology, ergonomics, typography and so on, and makes extensive use of feedback from users. Feedback is gathered using various techniques, such as questionnaires, observation of users, interviews and recordings of users in action. Recordings of users can take many forms also, for example timing, video recording, recording users’ spoken commentaries, and tracking software that records all the key strokes made by a user.

Like virtually all areas of design, usability design is (or should be) iterative. That is, a prototype is tried, evaluated, modified in the light of evaluation, tried again, and so on. It is especially important to try a prototype with the kind of people who will use the finished product. Sara Bly, who designs and evaluates interfaces, says:

Recently I was asked to design and evaluate an application for setting up personal preferences and purchasing services on the web. I was told it would be hard to test the interface ‘in the field’ because it was difficult to get a 45–60 minute test period when the user wasn't being interrupted. When I pointed out that interruptions were normal in the environment in which the product would be used and therefore should occur in the evaluation too, the client looked aghast. There was a moment of silence as he realised, for the first time, that this hadn't been taken into account in the design and that the interface timed out [that is, closed down after a period of inactivity, with loss of data already entered] after 60 seconds. It was unusable because the user would have to start all over again after each timeout.
Bly (1997)

This focus on the users of the system is an example of the human-centred design (HCD) approach. The HCD approach is intended to ensure that aims of the interface or service are fulfilled for real users. The term ‘users’ is understood to mean not just the customers or members of the public who use the interface for a particular service (sometimes referred to as end users), but also the people who have to operate and maintain the system.

The principles of good design for e-government systems are not significantly different from those for other systems. For instance, Cabinet Office (2003), Quality Framework for UK Government Website Design, offers these pieces of advice (among others):

A good government website should have some content that has been specifically written for the Web […][and] should not simply repeat printed brochures […]
Writing for the Web is a specific skill.
Cabinet Office (2003), p. 30.

Jakob Nielsen, who has written extensively about usability, similarly says that writing for the Web is very different from writing for the page:

People rarely read Web pages word by word; instead, they scan the page, picking out individual words and sentences. […] As a result, Web pages have to employ scannable text […]
Nielsen (1997)

Activity 26 (self-assessment)

The following two pieces of text are directed at managers of an e-government project, and offer advice on dealing with web designers. Which would be better suited for online presentation, and why?

‘A web designer should make it clear from the start what they will need you to do to quickly and effectively build your website. Content will be the major requirement. Indeed, it is often this aspect of putting together a website that takes the greatest amount of time, as the content must be collated and optimised for the Web. Ensure you have your content completed to the deadline you have agreed. This will ensure the designer/agency has no excuse concerning the completion of the project on time.’ (Cabinet Office, 2003, p. 44)
A web designer should make it clear what you need to do. Content will be your major contribution to the site.

Assembling content often takes longer than anything else. This isl because it needs to be:
- collated
- optimised for the Web.
Be sure to observe your deadlines, so that the designer/agency cannot blame you if the project runs late.

Answer

Text 2 is much more scannable (to use Nielsen's term) than 1. It is easier to take in text 2 at a glance than text 1. This is because the paragraphs are shorter, the sentences are shorter (and simpler), and important sequences of ideas are listed (‘collated’ and ‘optimised for the Web’).

Nielsen's reason for advocating scannable text is not just because it is easier to read, but because it helps the viewer decide whether the text is worth reading. This is important because Web use is as much about deciding whether a page looks useful as it is about reading what is on the page. As further aids to scannability, Nielsen advises the use of:

highlighted keywords (hypertext links serve as one form of highlighting; typeface variations and colour are others)
meaningful sub-headings (not ‘clever’ ones)
bulleted lists
one idea per paragraph (users will skip over any additional ideas if they are not caught by the first few words in the paragraph)
the inverted pyramid style, starting with the conclusion
half the word count (or less) than conventional writing
Nielsen (1997)

The price paid for concise web pages is loss of context and detail, but these can sometimes be supplied in other ways, for instance by headings, clear links and highlighted keywords, all of which Nielsen advocates.

The authors of Quality Framework for UK Government Website Design point to the importance of a search engine:

[A]n effective site-specific search engine is crucial to most good government websites.
Cabinet Office (2003), p. 33

Once again, this advice agrees with Nielsen's view of good practice:

Search is the user's lifeline when navigation fails. Even though advanced search can sometimes help, simple search usually works best, and search should be presented as a simple box, since that's what users are looking for.
Nielsen (1998)

In fact, for many users a search facility is not a second choice, to use when navigation fails, but a first choice that is often quicker and simpler than the navigation facilities.

Nielsen has at various times summarised his thoughts on usability in a list of principles. Here is one such list, slightly simplified by Preece et al. (2002).

Visibility of system status. Always keep users informed about what is going on, through providing appropriate feedback within reasonable time.
Match between system and the real world. Speak the users' language, using words, phrases and concepts familiar to the user, rather than system-oriented terms.
User control and freedom. Provide ways of allowing users to easily escape from places they unexpectedly find themselves, by using clearly marked ‘emergency exits’.
Consistency and standards. Avoid making users wonder whether different words, situations, or actions mean the same thing.
Help users recognise, diagnose, and recover from errors. Use plain language to describe the nature of the problem and suggest a way of solving it.
Error prevention. Where possible prevent errors occurring in the first place.
Recognition rather than recall. Make objects, actions, and options visible.
Flexibility and efficiency of use. Provide accelerators [for example, keyboard shortcuts] that are invisible to novice users, but allow more experienced users to carry out tasks more quickly.
Aesthetic and minimalist design. Avoid using information that is irrelevant or rarely needed.
Help and documentation. Provide information that can be easily searched and provides help in a set of concrete steps that can easily be followed.

Nielsen's principles apply to all types of computer interface, for example the interfaces to operating systems, word processors, calculators and so on, not just web interfaces.

Principles like these give you an evaluative framework, but they are not in themselves a quick tool for evaluating an interface. For instance, an interface that falls short on two of these principles is not automatically better than one that falls short on three. The evaluation has to take into account the way the interface is used, which will probably (among other things) lead to some principles counting for more than others.

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5.3 Accessibility

The Open University — Mon, 18 Jul 2011 08:33:16 GMT

In Section 5.1 you assessed the usability of Figure 11, the noticeboard in a public park. For a visually impaired person, that noticeboard might not be usable at all, as you may have commented. This raises the issue of accessibility. Accessibility relates to how well a service is adapted to the diverse abilities of all potential users. Disabled people and people with various kinds of impairment have an interest in accessibility, but accessibility is not exclusively concerned with their needs. For example, users of online services might be using mobile phones or PDAs (personal digital assistants) to access the services, or might have slow connection speeds. If people have difficulties using the services because of their equipment, then they have accessibility problems. Accessibility therefore overlaps to some degree with usability.

Activity 27 (Exploratory)

How might a web designer cater for users with slow connections?

Discussion

One of the most useful ways of catering for users with slow connections is minimising the total size of files that are downloaded when web pages are accessed. Large files take a long time to download and therefore cause delay. The solution is usually to avoid large graphics files, sound files or video files. Sometimes a text-only version should be offered.

Generally designers want their sites to be usable and accessible by all users, in so far as that is feasible. In the UK, at the time of writing, there is also a legal dimension: disabled people have a strong legal case if they can show that failure to take account of their needs has disadvantaged them.

Some of the features required for good accessibility are easy to envisage. For instance, some users need to be able to adjust font sizes, screen resolution, and so on. Other users might find particular combinations of foreground and background colour make text hard to read. However, the accessibility implications of other features of interfaces are not so readily apparent. Some users, for instance, have a screen reader, which uses a synthesised voice to read on-screen text aloud. Other users have a speech-driven web browser, in which commands are spoken into a microphone. These are examples of adaptive technology or assistive technology, and the design of a website can considerably help or hinder their use. For example, many web pages have a panel on the left or at the top with links to other parts of the site. The sighted user can easily ignore these if they are of no interest. Screen readers, however, often begin by reading out these links. This can be useful on the first visit to a site, but on subsequent visits it can be frustrating for the user to have to endure the same recitation of links. A ‘skip navigation’ link or button right at the start of the page allows the user of a screen reader to skip this part of the page. In an accessible design, this ‘skip navigation’ facility can be invisible to a sighted user, but so placed that it is the first thing read by a screen reader.

For people who use a keyboard rather than a mouse, navigation is made easier if there are access keys. These are more-or-less standard keyboard shortcuts that can be incorporated into web pages. For instance, Alt 1 generally jumps to the homepage, Alt 4 jumps to a search facility. Alt 2 is generally a ‘skip navigation’ link, taking the user straight to the main content of a page.

Activity 28 (exploratory)

There are some optional accessibility features built into Windows, and you should spend a few minutes investigating them. If you go to the Control Panel (reached from the Start button, and possibly then via ‘Settings’), you should see an icon labelled ‘Accessibility Options’. These give you options relating mainly to your mouse and keyboard. If there is an option ‘Configure Windows to work for your vision, hearing and mobility needs’, note this will launch a ‘wizard’ that allows you to change your settings. If you are concerned that you might not be able to undo any changes, be sure not to select any modifications that are offered.

Depending on your version of Windows, you may find further accessibility tools if you go to the Windows Start button, choose ‘Programs’, select ‘Accessories’, and then select ‘Accessibility’.

Discussion

When I looked at these I was struck that the options available were quite modest: changes in text size in menus and dialogue boxes, the option to drive the cursor using the keypad rather than a mouse, and so on. I was interested to see that ‘sticky keys’ allows keys that sometimes have to be pressed simultaneously with other keys (mainly shift-, control- and alt-) to be pressed in sequence. I was very surprised that no single action can be used as a substitute for double-clicking.

Figures 12 and 13 show an example of an accessibility tool, developed in New Zealand. The Lomak (‘light operated Mouse and Keyboard’) replaces a standard computer keyboard and mouse. The user directs a light source at the keyboard to get standard keyboard and mouse functions. The light source can be worn on the head or be hand-held.

View larger image

Figure 12 The Lomak keyboard. Standard keyboard and mouse functions are obtained by directing a light source at the keyboard

Long description

Figure 13 Lomak keyboard in use. The user is wearing the light source on her head, and directing it with head movements

Long description

Further information on accessibility aids can be found by searching the Web with terms such as ‘adaptive technology’, ‘accessibility aids’ and ‘accessibility software’.

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6 E-government: other views

The Open University — Mon, 18 Jul 2011 08:33:16 GMT

As you come to the end of this unit, I would like to offer some alternative views of what e-government could or should be. What these views have in common is the notion that ICTs have the power to transform radically the way things are done.

We saw at the start of unit that in the UK the e-government project grew out of ideas about modernising government. This is true of many other countries’ e-government projects also. What ‘modernisation’ means is not entirely clear, although it presumably involves managerial and organisational changes as well as the use of ICTs. But, whatever it involves, for many critics of e-government there is a feeling that the institutions of government will remain in control of the way ICTs are used by government.

There are other views of what e-government should be like. Implicit in many of these views is the idea that democratic e-government is not just about government services being put online. Instead, there is a view that democracy involves critical scrutiny of government. From this point of view, ICTs are seen to offer new tools for this critical scrutiny, and new ways of interacting with government. ICTs therefore open the way for a different kind of e-government. The following extract, from the Guardian newspaper, gives a flavour of this other view:

Tom Steinberg, director of mySociety and a former adviser to No 10, wants the project to show off the success of the people he calls ‘civic coders’. Their grassroots projects typically run queries on data already published by the state, returning relevant information which is fed onto elegant, minimalist websites. Simple social software tools – email, blogs, message boards, wikis – add the crucial layer of interactivity, and in one swift hack, citizen is brought closer to state.
FaxYourMP is the canonical example. Stefan Magdalinski, one of the site's volunteers, says the site came about because, ‘we don't see why people should have to jump through hoops to contact their elected MP’. The site runs a postcode query to establish who your MP is, then presents you with a simple email form that quickly becomes a fax appearing in the MP's office. Run completely by volunteers, the site won the 2004 Future UK Internet Hero award and recently sent its 100,000th fax.
FaxYourMP and the websites that followed it picked up tricks the government had missed. The sites have seen ways to recycle data the government already publishes, increasing the usefulness of that data, without incurring much further cost.
Hogge (2004)

mySociety is an umbrella organisation of 'grassroots' e-government projects. No. 10 refers to 10 Downing Street, the official home of the British Prime Minister.

These ‘grassroots’ e-government organisations often criticise governments for not presenting information in a useful way:

One thing he [Stefan Magdalinski, responsible for www.theyworkforyou.com] himself wants is for the Government to get out of the business of creating portals that the public is supposed to use as a gateway – […]. ‘They should get good at search-engine optimisation and which service-delivery points they want to optimise. If they want serious uptake, promote the places where you can actually pay your road tax above all the other areas.’
More than that, says Magdalinski, they need to do a lot more to make data feeds available in formats that third parties can use. His own website is a case in point. ‘The e-government framework has been going on for some years, but they still publish everything in PDF.’ PDF, Adobe's portable document format that preserves formatting and can be read on almost any computing device, is good for forms and material that is going to be printed. But why produce the recent listing of MPs’ expenses in that way, which makes it impossible to search them and to sort them meaningfully?
For the kinds of services Magdalinski builds, PDF is a hindrance. He wants data published in standard machine-readable formats designed to allow re-use by third parties. By the next general election, theyworkforyou.com should be able to provide a detailed scorecard on every MP: voting record, speeches made in Parliament, expenses claims. And why shouldn't charities like the Royal National Institute for the Blind be able to scrape all relevant government information – legislation, direct links to benefits – into a website that is designed to make life easier for its members?
Grossman (2004)

You can perhaps see here the emergence of a different view of the role of ICT in relation to government. In the ‘conventional’ view, ICT does not fundamentally change the relationship between government and the public, but allows government to do more efficiently and cheaply the kind of thing that it has always done, such as supplying information, collecting taxes, and so on. In the other, more subversive view, ICT has the potential to change the relationship between government and public, and to lead to different kinds of democratic process.

It seems particularly appropriate to end this block, by thinking about ICT's capacity for transformation. Like many new technologies, ICTs at first offer quicker or cheaper or more efficient ways of doing what is already done in other ways. But the cheapness, speed and accessibility of these technologies have a way of encouraging novel applications, by new groups of users – as demonstrated by the grassroots organisations mentioned in this section. ICTs can thus transform the world in ways that could not have been predicted at the outset. The early proponents of e-government would almost certainly not have viewed e-activism as part of their agenda.

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The Open University — Mon, 18 Jul 2011 08:33:16 GMT

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References

The Open University — Mon, 18 Jul 2011 08:33:16 GMT

Bisson, S. (2005) ‘Mark of success’, Guardian 'Life’ supplement. 10 February, p. 16.

Bly, S. (1997) ‘Field work: Is it Product Work?’, ACM Interactions Magazine, January and February, pp. 25–30; quoted in Preece et al. (2002), p. 387.

Bowcott, O. (2004) ‘Top security jails install fingerprint scan at gates’, Guardian, 5 August, 2004.

Cabinet Office (1999) Modernising Government, London, Cabinet Office. (The Cabinet Office documents are available online and can be downloaded as PDF documents from http://www.cabinetoffice.gov.uk/publications/ [accessed 11 September 2006]. Use the search facility to find a document by title.)

Cabinet Office (2000) e-Government: a Strategic Framework for Public Services in the Information Age, London, Cabinet Office.

Cabinet Office (2003) Quality Framework for UK Government Website Design: Usability Issues for Government Websites, London, Cabinet Office.

Cross, M. (2005) ‘Local solution to the Identity Crisis’, Guardian, Online supplement, 31 March 2005, p. 16.

Dempsey, P. (2005) ‘Knowing me, knowing you’, IFF Information Professional, Institution of Electrical Engineers, February/March 2005, pp. 14–18.

Dettmer, R. (2004) ‘Safety in Numbers’, IEE Review, vol. 50, no.ll, November, pp. 28–9.

The Economist (2005) ‘New Look Passports’, 19 February, p. 83.

Grossman, W. (2004) ‘Are We E-fficient?’, The Independent, Science & Technology, 24 November, p. 11.

Hogge, B. (2004) ‘Closer to the state’, Guardian Online supplement, 2 December, p. 19.

Mansfield, A. and Rejman-Greene, M., (2003) Feasibility Study on the Use of Biometrics in An Entitlement Scheme, National Physical Laboratory, Teddington, version 3. Available online at http://www.npl.co.uk/scientific_software/research/biometrics/ [accessed 11 September 2006]

Musgrave, S. (2005) ‘Community portals – the UK experience’, Journal of Community Informatics, vol. 1, no. 2, p. 35.

Nielsen, J. (1997) ‘How users read on the Web’ [online] http://www.useit.com/alertbox/9710a.html [accessed 11 September 2006].

Nielsen, J. (1998) ‘Top Ten Mistakes in Web Design’ [online] http://www.useit.com/alertbox/9605.html [accessed 11 September 2006].

Preece, J., Rogers, Y. and Sharp, H. (2002), Interaction Design, Hoboken, Wiley & Sons, p. 27.

Say, M. (2005) ‘The Information Man’, Government Computing, Vol. 19, No. 2, February 2005, p. 16.

Silcock, R. (2001) ‘What is e-government?’, Parliamentary Affairs, Vol. 54, No. 1, January, p. 97.

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Acknowledgements

The Open University — Mon, 18 Jul 2011 08:33:16 GMT

Except for third party materials and otherwise stated (see terms and conditions), this content is made available under a Creative Commons Attribution-NonCommercial-ShareAlike 2.0 Licence

Grateful acknowledgement is made to the following sources for permission to reproduce material within this book.

Text

Roger Dettmer, ‘Safety in Numbers’, IEE Review, vol. 50, no. 11, Nov 2004.

Hogge B., (2004) ‘Closer to the State’. The Guardian Newspaper issued 2 December 2004.

Figures

Figure 12 By permission of Lomak International

Figure 13 By permission of Lomak International

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