Factors to be taken into account when designing 'walk up and use' systems are:
- System users may be infirm, or disabled so will not be able to respond quickly to requests.
- Users may not be able to speak the native language of the country where the machine is installed.
- System users may be completely unfamiliar with technology and may make almost any kind of error in using the machine. The interface must minimise the number of possible errors and must be resilient to any possible error.
- Some system users are likely to be intimidated by many options. On the other hand, as users gain familiarity with the system, they may expect to use it for a wider range of banking services.
- Different people may understand the meaning of icons in different ways. • If the system has navigation options, users are almost certain to become lost.
- Most users will want to use the system for very simple functions (e.g. withdraw cash from an ATM) and will want to do this as quickly as possible.
There are many different ATM interfaces so each must be considered separately. Problems that I have found are:
- When is it possible to cancel a transaction?
- What happens when I do so?
- What will I have to re-input if I restart the transaction?
- There is not usually any way of saying give me the maximum amount of money I may withdraw today.
- Some machines only support single transactions - there is no way of saying I will be making several transactions and the same validation process is applicable to all of them.