Recommendations.
If electronic purses become as widely used as planned, they may become the only acceptable way of payment for some services. The current designs for electronic purses raise concerns about the way elderly and disabled persons will be able to use these systems. If the purse systems are not well designed they could exclude many potential users.
The following recommendations address some specific problems. Our aim is to encourage all designers to test their designs with a cross section of potential users, which will include disabled and elderly people. Good design for people with disabilities is frequently good design for everyone.
Numeric and command buttons.
A standard layout for keypads is recommended. There are two common layouts for numeric keys; the telephone layout and the calculator layout. It is recommended that the telephone layout be used, as shown.
Screen displays.
A high contrast display with larger characters will significantly improve legibility for most people with low vision.
A typeface with clear and easy to distinguish characters should be used, eg. 'Screenfont', see website www.eyecue.co.uk/tiresias.
Card Entry.
It is useful to have a funnel opening to guide the card into the reader; this is particularly helpful for users who have low vision or hand tremor.
Larger buttons and tactual feedback.
Larger buttons which have clear visual markings and tactual feedback should be used. Tactual indication 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 of cushioning.
To help blind people, there should be a single raised dot on the number 5 key. This should be positioned so as not to reduce legibility.
Card orientation.
Blind persons, and many elderly persons, have problems in inserting the card in the correct orientation. All electronic purse cards should include a tactile identifier for card orientation (in accordance with standard EN 1332-2).
Access to terminals.
At the retailer's premises, it is important that the visual display is positioned such that the customer can easily read it before agreeing to the completion of the transaction. For customers with low vision, this requires that they can get close to the high-contrast visual display.
Speech output.
The possibility of speech output for some devices should be considered. If this is not wanted for all customers, this requirement could be coded on the user's card (in accordance with standard prEN 1332-4, see Standards ).
Braille.
In outdoor conditions, Braille has 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 0.02% of the population; so although useful for some blind users, Braille is not a total solution for visually impaired users.
Screen phones.
For visually impaired persons, provision of adapted screen phones at affordable prices is likely to be crucial if they are not to be excluded from using electronic purses. These phones might offer other facilities such as caller line identification and access to home shopping services.
Training.
Serious consideration should be given to training in the use of the purses and the systems they link into; and who is responsible for providing this training. Training schemes should include production of clearly written instruction booklets in large print.
Keeping communications simple.
Given that retail or public transport environments tend to be bustling and distracting places to be in, all designs should aim to make electronic purse systems as simple to use as possible. Communication between the devices, terminals and the user should be direct and simple. For example, for intellectually impaired persons, it might be useful to have a simple balance reader which shows the balance pictorially or have that person's card specially coded to show pictoral information.
Further information.
The publication Access Prohibited? Information for Designers of Public Access Terminals gives detailed information on the design of public access terminals. This is available on the world wide web at www.tiresias.org/pats/index.htm