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The Development of Information and Communication Technology Systems to Include People with a Visual Impairment


Dr. John Gill
December 2002


Increasingly people with a visual impairment need to be able to use equipment designed for the general public; this includes ticket selling machines at unmanned railway stations, cash dispensers, and public telephones. In the foreseeable future, inability to use such systems is likely to increase the divide between the visually impaired and fully sighted population; these systems could include next generation mobile phones, interactive television and electronic purses.

Therefore it is essential that equipment for use by the general public is designed to be accessible by as many people as is reasonably possible. With the increasing ageing population, this must include people with presbyopia as well as people with a combination of different impairments.


Inclusive design

Inclusive design is the design of mainstream products and/or services that are accessible to, and usable by, as many people as reasonably possible on a global basis, in a wide variety of situations and to the greatest extent possible without the need for special adaptation or specialized design. As yet, this 'inclusive design' message has had limited practical impact upon the area of information and communication systems and services.

In the case of cash dispensers, the companies manufacturing the equipment see their customers as the banks purchasing their equipment. Even though they may have incorporated inclusive design features in their range of terminals, it is to no avail if the bank is not interested in offering it to their customers. Within the bank it may be a technical department which is responsible for selecting equipment for the bank, but it will be the local branches who have direct contact with disabled customers and who may provide a modicum of training in the use of the cash dispenser. Unfortunately local branch staff are unlikely to be aware of the technological possibilities for improving the accessibility of the equipment.

At the policy level it may be sufficient to specify that the equipment and services must be accessible to as many people as is reasonably possible. However this leaves open many questions including what does 'accessible' mean? Also what is 'reasonable'? Also it does not cover the often crucial question as to who pays for any additional costs such as training.

The development of guidelines for inclusive design of systems and services in the area of information and communication technologies is seriously hampered by the sparcity of sound scientific data about the needs of people with disabilities. What data exists is all too often based on inadequate sample sizes or inappropriate methodology. This is an area which is perceived to be low on academic content. Industry wants guidelines to be pan-disability, but this will require greater collaboration between all the relevant organisations representing the different disability groups.

With new equipment and services which are only in the early stages of specification, such as third generation mobile communications, it is difficult to be precise. However if the influencing is left to the stage when it is clear what features will be incorporated, it is often too late to get anything significant changed.

Information for product designers may be detailed design guidelines (eg the maximum height and angle of a display so that it can be read by a wheelchair user). However this approach is only possible for established technology for which detailed design guidelines exist. In other cases it will be necessary to provide generic guidelines backed up by recommendations on how to test prototypes with a cross-section of potential users. For telecommunication designers the problems are shortage of time and lack of an established system for evaluating with disabled users. This is an area where user organisations could take a more active role in providing speedy evaluation of prototype systems and services.


Standardisation

Standards are crucial in the telecommunications industry where there is a rigorous, but sometimes slow, process for developing standards. In the television industry, the process is somewhat different in that the technical standards are frequently determined by bodies made up of only industry representatives and there is no policy for involving consumers. The situation is different again in computer software where the commercially dominant players set the de facto standards with apparently no consultative process. This means that convergence is going to involve a clash of cultures as well as the more obvious problems of integrating three different groups of technology.
Standardisation is slow, time consuming, lacks academic content and sometimes has limited direct commercial benefit. Academics shun the area since it does not produce research publications. Industry is hesitant about inclusive design standards work since they can see no short-term commercial benefit.

Standardisation has four phases:

  1. Deciding what needs to be standardised and finding experts to participate in the work.
  2. Writing the precise standard; this requires detailed technical knowledge as well as good understanding of the implications of various impairments.
  3. Implementing the standard (ie encouraging the key players to take it up).
  4. Publicity so that disabled people are aware of the facility or service.

Industry and many government departments feel it is the role of the organisations of disabled people to assist with the implementation and awareness phases. However the disability organisations have often taken the view that they should be paid to do this work.

Since governments now see the primary purpose of standards as facilitating trade, the role of the consumer has become somewhat uncomfortable. Therefore legislation or mandatory regulation would appear to be the only practical way of requiring commercial organisations to adopt inclusive design principles. However the current trend is towards minimising regulatory control, and European legislation does not appear likely in the near future.


Public terminals

The solutions to some of the problems of people with disabilities may appear trivial to a non-disabled person, but they can nevertheless have a major effect on the usability of a piece of equipment or access to a service. For instance many people would like a notch in the facia of the terminal, such as a cash dispenser, so that they can lean their walking stick against the terminal without the stick falling over. Other problems require more complex modifications, but often solutions are available yet not implemented.

For many disabled and elderly users, the most important aspect is consistency in the user interface of public terminals; this is particularly important for visually, intellectually and cognitively impaired users. With a public terminal, the user may only use it occasionally and has probably been provided with minimal training in the use of the terminal. What is 'logical' to the average user may be different from what is 'logical' to the designer, so it is essential to test any new user interface with a cross-section of potential users (including disabled and elderly people).

To select a preferred interface such as audio instructions or large characters on the screen, the user could simply press a button or otherwise select from a menu on the screen; this is likely to increase the time taken to undertake a transaction if there are more than a few options. Another possibility is to store the user's preferences on a central computer and implement them as soon as the PIN (personal identification number) has been entered.

For card-operated terminals, it is possible to store the information on the user's card (the coding of user requirements is specified in the European standard EN1332-4), and this is in many ways more desirable than storing private information about a user on a central database. With a magnetic stripe card there is very limited spare capacity for storing this information (but this method has been used for storing the user's preference for displayed language), but a smart card (containing an electronic chip) has fewer restrictions on storage capacity so appears to be ideal for this purpose.

For blind persons, it can be difficult to find the terminal if they are not familiar with the environment. One possibility is to use a contactless smart card, carried by the blind person, to trigger an audible signal from the terminal at a distance of a few metres.

Public access terminals can incorporate audio prompts in the form of 'beeps', to indicate an action. It is recommended that new equipment should provide a more sophisticated solution of using audio leadthrough in the form of a verbal set of instructions. Message content should be chosen very carefully since a message that might be acceptable to the users for the first few times they hear it may become unacceptable when they hear it for the hundredth time.

People who wear bifocals find it difficult to read the screen of most public access terminals, since neither lens gives a focussed image for the distance between their eyes and the screen. In addition many people leave their spectacles in the car or do not wear them in public. So the number of people who have problems in reading the screen is much more than those considered 'blind' or 'low vision'.
People with low vision should not be prevented from getting their faces close to the screen. However it is possible to increase the size of the characters on the screen for individual customers who require this facility. This can be done by selecting this option from a menu or preferably by storing this information on the customer's card. With touchscreen systems, it could be arranged that holding one's finger in the top left corner for at least two seconds indicates that one would like double size characters on the screen. Ambient light, such as from an illuminated sign above the terminal, can cause problems if it results in glare or reflections from the screen.

Digitally stored speech can give very good audio quality, but it is effectively limited to pre-stored messages. Full vocabulary synthetic speech is often difficult to understand for the naïve user, particularly if they have a hearing impairment. Non-confidential information can be output on a loudspeaker, but the volume should be a function of the current ambient noise level; this is less of a problem with handsets or headphones. One technological possibility would be for a disabled user to have a hand control unit with an infra-red or radio link to the terminal. It may be that Bluetooth becomes the standard interface, but still there is a problem in persuading service providers to fit it to all terminals (which would include retrofitting to existing terminals).

Displayed text should use simple, large, bold fonts in upper and lower case characters. Displayed messages should be simple in sentence structure, use natural language, and any graphical symbols (such as icons) should be accompanied by text. Information, which is sensitive and private to the cardholder, should not be visible to any other person; screen filters, which act like a slatted blind and restrict the user to be directly in front of the screen, improve privacy but often at the expense of visual quality. However users may wish to display information with a large character size, but they should be made aware of the privacy problem.


Keypads

Standard layout of keypads is essential for visually impaired people and highly desirable for other users. To help blind persons, there should be a single raised dot on the number five key. However this does not solve the problem of there being two common layouts for the numeric keys (ie the telephone and the calculator layouts); it is recommended that the telephone layout is used exclusively on public access terminals. Ideally keys should be internally illuminated when the terminal is waiting for input from that keypad. There should be some form of feedback on key input (eg a beep and/or tactual indication). Tactile feedback can be provided by a gradual increase in the force, followed by a sharp decrease in the force required to actuate the key, and a subsequent increase in force beyond this point for cushioning.

Illustration of different keypad layouts

With a keypad, the spacing of the raised keys is as important as the size of the keys; the keys should be a contrasting colour to the background. A concave shape to the keytop helps visually impaired people as well as those with poor hand coordination. Membrane keypads pose particular difficulties, which can be alleviated by clear tactual markings (eg raised lines between the active areas).

Many elderly people and those with a cognitive impairment do not like to be rushed or to think that they are likely to be 'timed out' by the machine, so it is necessary to allow for such people to use the terminal at their own pace; this requirement could be stored on the user's card.


Touchscreens

Most visually impaired people would prefer to use buttons instead of a touchscreen, but this is not always practicable. To help elderly people and those with hand tremors, key fields should be as large as possible and separated by a 'dead area'. There should be high contrast between touch areas, text and background colour. Using a pretty picture as background is problematic for anyone with poor vision or someone reading the screen under difficult conditions (eg in bright sunlight).

For blind users, one possibility is to arrange that holding one's finger in a specified corner of the screen for at least two seconds initiates speech output (NB this must be a different corner than the one used to request large characters on the display), or tapping twice in the corner. Another method would be to store this requirement on the user's card.

Touch screens can either be triggered by insertion or withdrawal of the fingertip. With the latter system, it is technically possible for the user to pass their fingertip over the screen and get speech output describing the active area they are touching at the time. Then the system is only triggered by withdrawing the fingertip from over an active area.


Fonts

To aid visually impaired users, receipts should have a minimum font size of 12 point with a clear typeface with upper and lower case text, but 16 point would be preferable if space permits. It is important that the print has good contrast on opaque paper with a minimum of background pattern. A common complaint is poor print quality on receipts which can be a result of the printer ribbon not being replaced regularly.

For people with low vision some numerals such as 6, 8, and 9 can look very similar in typefaces such as Arial or Helvetica. Therefore it is advantageous to use a typeface with open shapes, designed to make each character as clear as possible. Characters such as the lower case 'l' should be designed to ensure they are different from the numeral '1' or an upper case 'I' when confusion would cause problems such as in email addresses.

Example of an email address and numerals  in Arial font

Example of an email address and numerals in Times Roman font

The optimal font for legibility will vary from individual to individual. However a font has been designed specifically for those with lack of central vision, as is common with macular degeneration, who want to read large print publications (further information www.tiresias.org/fonts).


Telecommunications

There has been much speculation about the impact of the coming together of computing, telecommunications and broadcasting, but as yet it has had little practical effect. However this will change over the next few years, and it will open up new possibilities for services to help visually impaired people. It is difficult to predict what new services will be available since the limitations will be mainly commercial viability rather than technical feasibility.

Mobile telephones increasingly require the user to read a small liquid crystal screen to operate many of the functions in the phone. Although the phones incorporate increasingly powerful microprocessors, manufacturers have not seen a commercial opportunity in providing models which incorporate speech output of the messages normally displayed on the screen. However there are some indications that this may change because car drivers are seen as a significant market segment.

WAP (wireless application protocol) is a system for accessing a number of special websites; unfortunately the system is very slow and there are few compatible websites. It can be used for financial transactions such as reloading an electronic purse. Extra functionality to suit visually impaired users could be built into the terminals, but this in itself is unlikely to provide full access to services. Therefore it will be necessary to modify the server or proxy server. The WAP User Agent Profile Specification covers aspects of the technical interface and the User Preference Profile concerns content selection (eg the user is interested in receiving sports scores); neither of these profiles covers the needs of people with disabilities.

This could be done in the form of a user profile which is stored on the smart card in the user's phone. There is a European standard for coding the user's preferred interface, but this will need to be extended to allow for the facilities needed by mobile phone users who have disabilities. This standard already incorporates facilities for specifying preferred text size, screen colour and speech output of the contents of the visual display.

GPRS (general packet radio service) is a high speed packet data technology which permits data transmission speeds of up to 100 kbit/s over the GSM (global system for mobile communications) network. This is well suited for frequent transmission of small amounts of data such as access to the internet. However it could be overtaken by UMTS (universal mobile telecommunications system).

UMTS is the next generation of mobile telecommunications system which will have seamless operation between terrestrial and satellite links. It will provide high speed access to the internet with data rates of up to 2 Mbit/s for a stationary terminal, less when on the move. It will include packet data transmission with the potential to adjust bandwidth on demand for asymmetric traffic. In the UK the network licenses have been sold by the government for vast sums (the first five licenses sold for over £22.5 billion) which will have to be recouped from the users.

UMTS will permit the transmission of video. For instance a blind person might send a picture to a service centre where a sighted person could give instructions on how to reach the desired destination. Another possible use for UMTS would be to download talking books during the night; a typical novel would take about 20 minutes to download using MP3.


Electronic purses

For some time pre-payment cards have been in general use for applications such as public telephones. These disposable cards are loaded with a fixed amount of value, which are then decremented during use. The next development was to make the cards reloadable which can be done at specialised terminals or automated teller machines (cash dispensers). Then it was only a small step for the cards to be used for more than a single application; these cards are called electronic purses.

However these systems vary significantly depending on the type of organisation operating the service. Historically the banking organisations have placed great importance on security, whereas public transport operators have been more concerned to minimise the time taken to complete the transaction.

Some electronic purse systems offer the facility to transfer funds between the card and the customer's bank account using a screen phone. Screen phones can be modified to be accessible by blind people, so this method of loading a card could be the preferred mode for many blind and partially sighted users.

For visually impaired persons, the main problems with electronic purse systems relate to the user interface. In particular many of the devices, such as balance readers and electronic wallets, have poor contrast visual displays which also pose problems for many elderly persons. One possibility would be to have special versions of the balance readers and wallets for those who cannot read the standard versions. Such a special wallet / balance reader might include:
High contrast display with larger characters (or speech output).
Larger buttons which have clear visual markings and tactual feedback.
A funnel opening to help guide the card into the reader.

A significant aspect of electronic purses is that the user does not need to have a bank account or even be credit worthy. This is likely to make electronic purses the preferred method of remotely paying for shopping by many older visually impaired persons. Another attraction for this group of customers is that as soon as the transaction has taken place, they can check the remaining balance on their electronic purse; unlike credit or debit cards, there is no risk of an unexplained item appearing on a future statement.


Interactive digital television

Interactive television is attracting considerable investment as it is seen as a significant step in selling new services to customers who may not be computer users. The UK government envisages that it will be a major method of interaction between the public and the government within five years. Traditional television can be characterized as one-to-many whereas the internet would be characterized as many-to-one. As yet interactive television is frequently just an enhanced one-to-many system with uncertainty as to how to satisfactorily also be a many-to-one system.

Some systems offer email: which is proving popular in the UK among those who do not have access to a computer or have no inclination to use one. Currently there are no facilities for enlarging the text or changing colours which gives problems for many visually impaired users.

In the future, the remote control for the television might be a mobile phone, connected by Bluetooth, into which is inserted the electronic purse to pay for goods and services.


Conclusion

New information and communication technology systems offer the possibility of greater usability by people with a visual impairment, but these opportunities will be lost if the needs of the consumer are not communicated to the relevant organisations. This will require collaboration between those undertaking research in this area, the organisations representing the consumer, the standardisation organisations, the regulators, the terminal manufacturers and the service providers.


Further Information
Gill, J. M. (1998) Access prohibited? information for designers of public access terminals. [accessed 22/10/07].

Gill, J. M. & Shipley A, D, C, (1999) Telephones: What Features do Disabled People Need? [accessed 22/10/07].

Gill, J. M. (2000) Which button? designing user interfaces for people with visual impairments. [accessed 22/10/07].

Gill, J. M. (2001) Keeping step? scientific and technological research for visually impaired people. [accessed 22/10/07].

Shipley, A. D. C. & Gill, J. M. (2000) Call barred? inclusive design of wireless systems. [accessed 22/10/07].

Vanderheiden, G. C. & Vanderheiden, K. R. (1992) Guidelines for the design of consumer products to increase their accessibility to persons with disabilities or who are aging. Wisconsin: Trace R&D Center.


 



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