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Access to Public Terminals by Disabled and Elderly People

John Gill

Summary
This paper examines methods for making public access terminals more accessible to all potential users, including disabled and elderly people.  To make significant progress in this area will require terminal manufacturers and service providers to adopt a 'design for all' policy.  In addition there will be a need to standardise a number of aspects of the user interface of such terminals.

 

Introduction
To fully participate in society, individuals will need to be able to use self-service terminals.  Many government departments in the UK have plans for using public access terminals for providing information, collecting taxes, granting licences, administering regulations, paying grants and benefits, collecting and analysing statistics, and procuring goods and services.  Some of these services may also be available through direct contact with a human, but there may be an additional charge for using this facility.

To make significant progress in the accessibility of public access terminals by disabled and elderly people will require terminal manufacturers and service providers to adopt a “design for all” policy.  In addition there will need to be agreement to standardise a number of aspects of the user interface of such terminals.

Design for All Principles
It is hoped that public access terminal manufacturers and service providers will adopt the following principles:
1.         The organisation will provide equipment and/or services that can reasonably accommodate a broad range of diverse users, including individuals with disabilities.
2.         The organisation will review its existing equipment and services to determine which ones need to be made more accessible.
3.         The organisation will design and develop equipment and services, to the extent readily achievable, so as to be accessible to a broad range of diverse users.
4.         The organisation will market its equipment and/or services in a manner consistent with accessibility by a broad range of diverse users.
5.         The organisation will employ these principles in its relationships with customers, employees, shareholders and suppliers.

The Americans with Disabilities Act in the USA requires terminals such as cash dispensers to be accessible to people with disabilities.  Although current disability discrimination legislation in Europe imposes few requirements on designers of public access terminals, this could change in the next few years.  The high cost of retrofits and the increasingly large number of people with disabilities means that it would be wise to consider their needs from the outset.

 

The Numbers of People with Disabilities
In geographic Europe (with a population of about 800 million), the estimated number of people with impairments (such that they have problems in using public access terminals) is:

Mobility Impairment
Reduced function of legs and feet leads to users depending on a wheelchair or artificial aid to walking.  In addition to people who are born with a disability, this group includes a large number of people whose condition is caused by age or accidents:
Wheelchair user                                 3 million
Cannot walk without aid                45 million

Dexterity Impairment
Reduced function of arms and hands makes activities related to moving, turning or pressing objects difficult or impossible.  This does not influence speech communication itself but makes it hard to make a phone call or use a wide range of other telecommunication equipment.
Cannot use fingers                            1 million
Cannot use one arm                          1 million
Reduced strength                            22 million
Reduced co-ordination                   11 million

Speech and Language Impairment
Speech impairment may influence speech in a general way, or only certain aspects of it, such as fluency or voice volume.  Language impairment may be associated with a more general intellectual impairment.
Speech impaired                                2 million
Language impaired                           5 million

Cognitive Impairment
Dyslexia can cause significant problems in remembering numbers in the correct order (such as a personal identification number).  People with an intellectual impairment can often function well in familiar environments, but can be easily confused when required to respond to instructions quickly.
Dyslexia                                          25 million
Intellectually impaired                    30 million

Hearing Impairment
Hearing impairment can affect the whole range or only part of the auditory spectrum which, for speech perception, the important region is between 250 and 4,000 Hz.  The term deaf is used to describe people with profound hearing loss such that they cannot benefit from amplification, while hard of hearing is used for those with mild to severe hearing loss but who can benefit from amplification.
Deaf                                                  1 million
Hard of hearing                               80 million

Visual Impairment
Blindness implies a total or near total loss of the ability to perceive form.  Low vision implies an ability to utilise some aspects of visual perception, but with a greater dependency on information received from other sources. 
Blind                                                 1 million
Low vision                                      11 million

Elderly
Older people tend to be slower to learn new skills, have difficulty in memorising and reacting quickly to instructions.  Also many elderly people prefer human assistance to using self-service terminals; however, this is not insuperable with suitable user interfaces and appropriate training.  Many elderly people use the telephone or video cassette recorder even though they may not be familiar with all of its facilities.
Elderly                                            80 million

 

It is not uncommon for an individual to have more than one disability; this is particularly common among older people.  The number of people over retirement age in Europe is likely to increase by over 1% per year for the next two decades, and as a result the number of people with disabilities will also increase

 

The Problems with Public Access Terminals
The solutions to some of the problems of many 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 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 but not implemented.  The table shows the problems with a cash dispenser for different groups of people with disabilities.


 


 

 

 

 

 

 

 

 

 

 

 

 

 

 

Locate terminal

 

 

 

 

 

 

 

l

l

l

Access to terminal

l

l

 

 

 

 

 

 

 

 

Read instructions

 

 

 

 

 

 

l

l

l

l

Insert card

l

l

l

l

l

l

 

l

l

l

Read screen

l

 

 

 

 

 

l

l

l

l

Use keyboard

l

 

 

 

 

 

 

 

l

l

Use touchscreen

l

 

 

 

 

 

l

 

l

l

Retrieve money

 

l

 

 

 

 

 

 

 

 

Read receipt

 

 

 

 

 

 

 

 

 

l

Retrieve card

l

l

l

l

l

l

 

 

l

 

 

     Few problems

          Some problems

         Many problems

            l  Technology available to alleviate the problem

Design Considerations
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.  A prime example of this is the lack of a single standard relating to the layout of numeric keypads.  With public terminals, 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 draft European standard prEN1332-4), 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.

Many disabled users would like to be able to select and store their preferred interface whenever they use their card at a public access terminal.  It is essential that information is stored on a card only with the consent of the user.

Locate Terminal
For blind persons, it can be difficult to find the terminal if they are not very 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.

For low vision users, signs should be large and high contrast (preferably white or yellow characters on a dark background) and illuminated (preferably internally illuminated).

Access Terminal
Where possible, there should be a continuous clear accessible path of travel for a wheelchair from car parking places to the terminal.  The floor surface should be level in the direction parallel to the facia of the terminal.  The gradient of any crossfall should not exceed 1 in 20.  There should be a clear area of 1.5 metres radius directly in front of the terminal, which should not be obstructed by litter bins or other street furniture.

Ideally there should be space beneath the facia of the terminal to allow for the footrest of a wheelchair.  A notch adjacent to the facia would be useful for those needing to prop their walking sticks while using the terminal.

Where queuing is likely, consideration should be given to some non-obstructive method of queue control (eg variation in colour of flooring or pavement) that maintains privacy and security for the user.

It is recommended that a background illumination of at least 50 lux be provided at floor level so that dropped objects can be easily located.  The illumination on the interactive areas of the interface should be at least 200 lux.  Most persons with low vision would prefer much higher levels of illumination, but service providers can be very reluctant.  The lighting should not cause any direct glare to the eyes of the users, or reflections from the screen.

Instructions
Instructions should be written in simple clear language and presented at eye height in at least 16 point bold characters, preferably in white or yellow on a dark matt background.  It is important that the instructions are not worn away with use of the terminal (or they should be replaced periodically).  It is often useful to number the instructions and then associate by number with the physical parts of the interface (eg card reader) as well as showing the number on the visual display.  Ideally the user should be able to choose the language; frequently this is only viable if the instructions are displayed on the screen, and it would be preferable if the user’s card stored their preferred language and that the terminal automatically switches to this as soon as the card is inserted.

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.  Audio leadthrough can assist people with visual or cognitive impairments (and first time users).  Sentences should be concise and simple in structure, and only natural vocabulary should be used.  Informative messages which advise the user of the progress of the transaction and inform the user when or how to perform a step in the transaction, should be clear and to the point, and provide confirmation of task completion.  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. Many users with impaired hearing, who can only hear lower frequencies, can more easily hear a male voice than a female one.

If audio output is used to provide private information to the user, then it should be through a telephone handset located at the terminal or through a headset connected through a standard mini jack to the terminal; however, it is essential that the position of the jack socket is standardised.  If a handset is provided, inductive coupling and amplification should also be incorporated.

Braille instructions on outdoor terminals have limited value in cold weather since tactual sensitivity is dramatically reduced with decreasing temperature.  The estimated number of braille readers in Europe is less than 200,000 so although useful for some blind users, braille is not a total solution for visually impaired users.

Card Insertion
For a blind person, there is a problem in selecting the right card from their wallet; unfortunately there is no standard method for tactually marking cards to indicate the issuer or their use.  This problem will be exacerbated with the increasing use of cards which feel the same.  Therefore it is suggested that card providers use an embossed capital letter at least 10 mm high with an embossing of at least 0.7 mm; even then there will be problems with differentiating cards outdoors in cold weather.

For the naïve user, it is often far from obvious where to insert the card.  A flashing light around the card entry slot has been found beneficial.  For those with hand tremor, it is useful if the entrance to the card reader acts as a funnel to guide the card in correctly.

Blind persons, and many elderly persons, have problems in inserting the card in the correct orientation; this is a particular problem on cards which are not embossed.  However there is a draft European standard for an orientation notch (prEN1332-2) in the card.

For many wheelchair users, such as those with arthritis, it is not just a problem of reaching the card reader, but still having any useful grip as the arm is raised above the horizontal.  If only a forward approach in a wheelchair is possible, then the maximum height of any interactive element on the terminal should not exceed 1.2 metres.  For a parallel approach in a wheelchair, then the maximum is shown in the table:

Reach in cm

Maximum height in metres

30

1.3

45

1.2

60

1.1

 

The lowest height of any operable part of the user interface should not be less than 0.7 metres. Ideally the terminal, or user controls, should be adjustable in height; although this is done on some drive-in cash dispensers, it does significantly increase the cost of the terminal.  However the problems of accessing the card reader are greatly alleviated if contactless smart cards are used; for this type of application they typically have an operating range of 10 to 20 cm.

Reading the Screen
People who wear bifocals find it difficult to read the screen of most public access terminals, since neither lens is in focus at 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”, who constitute about 1.5% of the population.

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.

Total colour blindness is rare (less than 0.0025% of the population) but problems with discriminating red and green are common (over 6% of the male population).

Moving text on a screen can be very difficult to read for someone with even a mild sight impairment, so it should be avoided whenever possible.

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.  If there is an inductive loop for hearing aid users, there should be a clear visual indication that this is the case (NB not all hearing aids have facilities for loop connection).

One technological possibility would be for a disabled user to have a hand control unit with an infra-red link to the terminal.  This would require all terminals to use the same interface protocol, and care would be needed to ensure confidentiality of sensitive information.  This approach is attracting interest in the USA, but is seen as too expensive a solution by many European organisations.

Sunlight can degrade the viewability of the display for all users. The site should be one where direct or reflected sunlight or other glare is prevented from striking the visual display.  The display should be viewable from an eye level of a person sitting in a wheelchair.

Display angle
degrees from vertical

Maximum height from ground
metres

0o - 30 o

1.3 metres

30 o - 60 o

1.1 metres

60 o - 90 o

0.9 metres

The conflicting requirements from tall pedestrian users and short wheelchair users can lead to a significant group of users having parallax problems when lining up the function keys with the displayed option.  Lines on the user-interface leading from the key to the surface of the display can alleviate this problem.

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.

Keyboard
Personal identification numbers (PINs) are a particular problem for many dyslexic and intellectually impaired people.  In Europe over 25 million people have dyslexia to the extent that they cannot reliably remember and use a four digit PIN, unless they can choose their own number.  The main problem for people with an intellectual impairment is to keep the number secret.  Therefore both groups would find it advantageous to have the option of using a biometric method for identification (eg fingerprint).

With biometric methods of identification it is essential that users have a choice between the biometric method and some other method (eg PIN); the reason being that for every biometric system there is some group of disabled people who cannot use it (eg fingerprint identification requires the user to have fingers).

The user’s PIN should not be displayed, printed or broadcast by any means.  However it would be useful to have both an audible feedback and a visual one (eg an X on the screen) to show that a digit has been input.  Many people with even slight memory problems find it difficult to remember and input their PIN quickly, so it would be helpful to allow a generous amount of time before they are timed out.

Information, which is sensitive and private to the cardholder, should not be visible to any other person; screen filters improve privacy but often at the expense of visual quality.  However the user may wish to display information with large character size, but they should be made aware of the privacy problem.

Standard layout of keypads is essential for visually disabled 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.

All keys or buttons should be tactually discernible; keys should be raised or recessed by a minimum of 2 mm.  The edges of the keys should be at least 2.5 mm apart.  Function keys should be clearly separated from the numeric keys.

Visual markings on the keys should be characters of at least 4 mm high and should have good contrast with the colour of the key (eg white characters on matt black keys). Where text keys are colour coded, they should be coloured as follows:

  Key meaning

  Colour

  Enter or proceed

  Green

  Clear or correct

  Yellow

  Cancel

  Red

Colour should not be the only distinguishing feature between keys, since red/green colour blindness is not uncommon; if possible, the keys should have different shapes and be marked with symbols.

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.

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.

Speech input for commands is an option in some situations.  If this is adopted then the user should have the choice of keyboard or speech input.  It is likely that speech input would be preferred by people without hands and those with intellectual impairments, but the keyboard is easier for those with a speech impediment.

Touchscreens
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.  Avoid using a pretty picture as background - it is a menace to 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.

Money Retrieval
Cash, receipt, or any other document issued from the terminal for withdrawal by the user should protrude at least 3 cm beyond the slot surround.

For someone with poor manual dexterity, such as with arthritis, taking a card from a terminal and then taking the money may be difficult to do in the allowed time.  Increasing the time for everybody, increases the security risk.  However it would be possible to let users decide if they want more time than the standard time permitted, and store this requirement on their card.

Security at cash dispensers is a major concern for many elderly people, and is often given as a reason for not using such terminals.  Therefore anything which improves the user’s perception of safety is to be welcomed.

Receipts
To aid visually impaired users, receipts should have a minimum font size of 12 point with a sans serif 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 is often a result of the printer ribbon not being replaced regularly.

Card Retrieval
Many people with arthritis have difficulty in gripping and pulling the card from the reader, particularly when the arm is extended above the horizontal.  The card should protrude at least 2 cm from the slot surround.  Therefore it is recommended that the force necessary for the user to retrieve the card from the terminal should be not any greater than that needed to stop the card from falling out of the reader.

Conclusions
Some suggestions would cost little to implement (eg the notch for the walking stick) and have no adverse effects on others.  Other suggestions are associated with a significant cost (eg contactless cards) but the cost can be partly justified by the new features being of use to more than just people with disabilities.  But there are some recommendations (eg levels of illumination) which might have an adverse effect on security for external terminals after dark; then it is up to society, through legislation or regulation, to determine an appropriate compromise.  Before this can happen there needs to be more research on possible adaptations and the number of users who benefit in practice from these modifications.

 

Publications
Ballabio E, Placencia-Porrero I & Puig de la Bellacasa R (Eds)   Rehabilitation Technology: Strategies for the European Union.   Studies in Health Technology and Informatics, Vol 9, ISBN 90 5199 131 2, ISSN 0926 9630, IOS Press, Amsterdam, 1993.

Brandt Å   Telephones for All.   Nordic Design Guidelines (NNH/3/95), The Nordic Committee on Disability, Stockholm, ISBN 87 89501 46 2, 1995. 

Copies free of charge, except for postage, from Danish Centre, Department of Technology, Communication and Special Education, Graham Bells Vej 1a, DK 8000 Aarhus N, Denmark (Tel +45 86 78 37 00;  fax +45 86 78 37 30;  Email daniscen@inet.uni-c.dk).

Clarke A   Human Factors Guidelines for Designers of Telecommunication Services for Non-expert Users.  Loughborough University, 1996. Primarily written for designers of telecommunication services and terminals for non-expert users, such as the general public. Available on CD-ROM from Anne Clarke, Husat Research Institute, The Elms, Elms Grove, Loughborough LE11 3BN, England (Tel +44 1509 611088;  Fax +44 1509 234651;  Email a.m.clarke@lboro.ac.uk).

Porreiro P & Puig de la Bellacasa R (Eds)   The European Context for Assistive Technology.  Proceedings of the 2nd TIDE Congress, Assistive Technology Research Series, IOS Press, Amsterdam, ISBN 90 5199 220 3, 1995.

Roe P R W (ed)  Telecommunications for All.  COST 219, The European Commission, CD 90 95 712 EN C, 1995.
This book gives a general overview of issues related to accessibility and usability of telecommunications equipment and services for disabled and elderly people.  The social, demographic and marketing aspects are also discussed while highlighting the significant role that can be played by standardisation and legislation.  The second part of the book looks more specifically at some of the available and forthcoming telecommunications equipment and services, identifying some of the existing accessibility problems and potential solutions. Out of print, but accessible on http://www.nta.no/cost219/cost95/indeks.html

Silver J H, Gill J M & Wolffsohn J S W   Text Display Preferences on Self-Service Terminals by Visually Disabled People.  Optometry Today, Vol 35:2, 30 January 1995, pp 24-27. This paper includes guidance on character size and colours for use on public access terminals.

Thorén C (Ed)   Nordic Guidelines for Computer Accessibility.   Nordiska Nämnden för Handikappfrågor NNH 4/93, 1993.
Copies available free of charge from Nordic Committee on Disability, Box 510, S-162 15 Vällingby, Sweden (Tel +46 8 620 18 90;  Fax +46 8 739 24 00).

 

 



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