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Inclusive Design of Interactive Television

Dr John Gill
Jim N. Slater
March 2000


There have been various European Union initiatives to promote 'inclusive design', whereby good design for disabled and elderly people is frequently good design for everyone. However, the first generation of digital set-top boxes and their associated remote controls have not been designed to suit the needs of elderly people and those with disabilities. The remote control handsets have numerous small buttons with legends that are difficult to see, making correct operation difficult for those with poor eyesight or dexterity problems, and the indicators and controls on the set-top boxes are difficult to see and to reach, especially when the so-called set-top box is mounted in its more usual position, underneath the television display.


Knowing your television audience

When it is known that a very large percentage of the television audience, especially during the daytime and non-peak viewing hours, is made up of disabled and elderly people, it seems surprising that broadcasters and equipment manufacturers have not given more thought to providing access to this group of people.

Unfortunately, the very word 'disabled' often conjures up completely wrong images of a small niche group of people who don't have much money to spend, and it is fascinating to learn some of the real facts, including the one that at any particular time this group will include around 0.5% of the population who are temporarily 'disabled' because of illness or accidents. That effectively means that perhaps 300,000 people in the UK who usually lead normal working lives could be at home watching television for a period of 'sick leave' on any given day - an ideal captive audience for the TV home shopping channels.


Market restrictions

If television receiver controls are difficult to understand or to operate, it is likely that many elderly viewers will not feel confident enough to take advantage of the new features and facilities that digital television can bring. Most of us can recollect having punched in a wrong digit on a standard Teletext handset, and then having to wonder just what to do about it. The controls on digital television receivers are more complex than those on a standard Teletext handset, not because they are more numerous, but because some of them lead to sub menus, and it is easy for an inexperienced user to 'panic'.


Home shopping - a wider market

The imminent introduction of home shopping via the digital television receiver will bring enormous opportunities for everyone, and it is good to see a new technology which could instantly benefit so many elderly and disabled people. Home shopping could be a boon to such people, and those wishing to sell goods and services to them should need no reminding that today's 'older people' form a growing and extremely valuable potential market.


Encouraging the use of new technology

The potential ease of use of digital TV based home shopping could also provide the motivation for them to make this new technology form a regular part of their shopping lives, both for run of the mill purchases such as groceries from the supermarket and more considered purchases, from fashionable clothing to household goods and furniture. On-line shopping and banking are areas that could be particularly useful for elderly people, but if they are going to be encouraged to give the new systems a try the broadcasters will need to ensure that they can see, use and understand the remote controls, and that they can navigate their way around the system without having to call on other people for help.


The disadvantages of ageing

There is no question, however, that even the healthiest of older people will suffer some impairments, physical and mental, and it makes good sense for those who are designing television based equipment to take account of these if they want to maximise the potential market for digital services such as home shopping.

People over 50 years of age naturally have less good vision than when they were younger. Bi-focals are common, more light is needed to see fine details, and reflective glare is often more problematical than for younger people. These visual disadvantages apply to the vast majority of 'ordinary' people who wouldn't consider themselves as being blind or partially sighted, but it is worth noting that there are in addition to all these people some 11 million people throughout Europe who are classified as having 'low vision', defined as an ability to utilise some aspects of visual perception, but with a greater dependency on information received from other sources. If the controls and displays on digital TV systems could be designed to suit people who have difficulty in seeing clearly, the market for TV interactive type services would be much expanded, at little cost.


Controls - handsets

Remote controls need clear visual markings, buttons (as few as sensibly possible) large and well separated to be selected and operated by fingers that have lost the flexibility of youth. The keys can have distinct shapes to help users distinguish between their different functions, and any text or symbols should be clear and well contrasted to the colour of the actual keys. The option for sound (clicks) and tactile feedback from the buttons should be offered, since experiments have shown that giving the user confidence that a button has been pressed can prevent superfluous presses that can lead to mis-operation and confusion. Mobile phones offer this option, why not TV handsets too?

Synthesised speech output from the control unit, confirming the action of each button, (e.g. 'Teletext, page 3-3-2' or 'channel 19 - home shopping' ) has been demonstrated to be very practicable, and needn't add too much expense to the controller. All these 'usability' features help a wide range of people, not just those who are elderly or disabled.

The shape of the control box should be designed for ease of holding whilst the buttons are pressed, and navigation buttons with arrows clearly indicating which part of a menu is to be moved to next are a great help. The infra-red beam transmission should cover a wide area so that the unit does not have to be precisely aimed at the infra-red receptor on the receiver.

Pre-programmed buttons for regularly used functions, the initial programming perhaps being done with outside help, could make the system much faster to use, and would make it easier to select and record wanted programmes, services, or text pages.

Future generations of digital receiver could work with voice control, which is becoming more and more practicable on computers, but requires more processing power than current designs of TV receiver can economically incorporate.


Displays

The RNIB Tiresias font, which was designed to ensure that individual characters are easy to discriminate, has been included in the subtitling specification, and has given rise to much interest throughout the world. Many practical tests have shown that the Tiresias Screenfont typeface is significantly easier to read than what went before, and already the designers are working to adapt the font for other purposes, from signage to bank cash machine displays.

The foreground and background colours chosen for the text and the transparency of the background are very important, especially for 'open' captions designed to be read by everybody; no programme producer will wish to see part of his carefully crafted picture area obscured by text on an ugly opaque background, and the choice of colours will determine whether or not the text is readable to a wide range of visually impaired viewers, as well as determining whether normally sighted viewers find the textual information easy and pleasant to read. In spite of the inevitable time and budget constraints of programme making, it could make sense for production staff to listen to experts in these areas of ergonomics and usability as they make programmes, if the resulting programmes can be meaningful and understandable to a far greater proportion of the viewers that they are trying to reach.

Character size ideally needs to be under the control of the user, with users being able to set their preferred size as the default setting for their receiver, and already researchers have shown how a smart card can be pre-programmed with the user's personal preferences so as to ensure that bank cashpoint machines automatically display large, appropriately coloured characters whenever the user makes use of the machine. Similar facilities could be applied to digital TV receivers, perhaps via 'technical set-up menus' which are only made available to those who need to adjust this type of feature. Choice of colours for foreground and background could also be under user control, which would aid people with various forms of colour-blindness, but it may well be that if the whole subject of achieving maximum readability and visibility with minimum disruption to the visual content of the programme has been considered as part of the production process, the need for local control could be eliminated.


Maximising the digital audience

It is in the interests of all those involved with the production of TV programmes and electronic information services such as Email, Tele-banking and home-shopping to ensure that their various services are available to as large an audience as possible. Demographic statistics clearly show that there will be an increasing population of elderly people over the next few decades, and designers of equipment, TV programmes, and the multiplicity of new digital services could maximise the take up of their services at modest cost in terms of both time and finance by thinking about how 'inclusive design' techniques might be simply applied to their particular areas of expertise.


A proposal for a study

The potential for the early and widescale adoption of electronic shopping techniques is vast, and their proper application could provide benefits to a wide range of people with disabilities. At a time when the roll out of such systems is just beginning, it is apt and important to take all possible steps to ensure that the systems that are developed are as ‘all-inclusive’ as possible, being designed in such a way that as many people as possible, of the whole range of abilities, can make beneficial use of the systems. Some initial research work has already been done by the RNIB on the subject of how electronic retailing will affect people with low vision, and this has highlighted a number of areas where detailed studies are required if we are to ensure that disabled people are not further disadvantaged by the introduction of electronic shopping systems. This type of research project would need to begin with a careful user needs and requirements study, would move on to examine in detail the multiple aspects of how the introduction of electronic shopping might affect people with many different types of disability, and could even consider the longer term implications of such changes in shopping patterns.

 

 



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