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CS-1Q: Class test (HCI Solution 1)

There will be one HCI question and one Information management question. You must answer BOTH questions in 1 hour and 15 minutes. This is an example of an HCI question.

These sample solutions provide some idea of what might be achieved in the time available. Other solutions are possible. They are not `ideal' solutions because more could be said about each of the issues that are explored. They are, however, sufficient to obtain a high mark in the class test and exam.


a) Briefly explain what is meant by the terms perception, physiology and cognition.

[Bookwork 3 marks]

b) Identify three different ways in which `functional ageing' can affect interface development.

[Seen problem 6 marks]

Functional ageing relates to the way in which a user's cognitive, perceptual and physiological capabilites may degrade at a rate that is faster than might otherwise be expected for their age. This form of ageing can be a particular problem for certain industries. For example, some commercial aviation pilots suffer significant sinus problems that ultimately may lead to hearing loss. Functional ageing can affect interface development in the following ways:

  1. it can affect an entire workforce and so additional cues and prompts may be introduced for all users who suffer from this problem;
  2. it may only affect certain individuals within a population and so studies will have to be conducted to determine whether initial assumptions about user capabilites hold for the entire group;
  3. the rate of functional aging may vary from individual to individual and so further studies may be needed to determine the extent of the additional support that may be necessary. Ultimately, it may not be possible for some people to use the system even with significant enhancements to the interface, for example in safety-critical applications.

c) Environmental factors can impair users' ability to recall information that is necessary to ooperate complex, computer systems. Brielfy explain how such disruptions can impair both short-term AND long-term memory.

[Seen problem 6 marks]

Short-term memory, typically, requires concentrated effort on the part of the individual concerned. If they become distracted by environmental factors then that concentration can be broken and the content of short-term memory may be lost. For instance, even a momentary distraction can cause a user to forget the name of a file or of a password that they havent used before.

The impact of disruptions on long term memory is less easy to explain. Typically, it is less easier to remember information that has passed from short-term to long-term memory. In consequence, a greater source of distraction or disruption would be required to impair their memory. A, typicaly, example is that even expert computer users may make mistakes if they attempt to perform two familliar tasks in parallel. Both may draw upon long-term memory but there can be interference effects.

c) You have been asked to help in the development of a new computerised call centre. Customers from a national Bank will ring up if they wish to change the details of their account. For instance, they might want to open a new account, close an old account, they might want to change the address of the person who owns the account and so on. Briefly explain how you might use two different requirements elicitation techniques to identify the potential usability problems that might arise for people working with this new system. Identify the principle strenghts and weaknesses of each technique.

[Unseen problem 10 marks]

There are many possible answers to this questions. You could propose questionnaires, interviews, focus groups. You could also use a summative evaluation technique, wlakthroughs and usage diaries to find out the weaknesses of the existing systems. These are techniques that can be applied simply and cheaply given the details that are provided in the question. Alternatively, you could propose the use of a more process-oriented approach such as rapid prototyping and participatory design. These techniques can build on an initial requirements elicitation by trying to identify additional problems and opportunities as the development progresses. In the course we also mentioned markey survey techniques, such as photo diaries. I'm not sure how these techniques might be applied to this question given that the client is alredy identified in some detail. However, you could propose more general; studies of the intended user population. In any event, the ideal solution should pick two complimentary techniques. For instance, questonnaires can provide a rough and ready impression of existing usability problems. These might be backed up with more detailed summative evaluations of the exisitng system etc.

Back to the Class test page.

Chris Johnson,
Dept. of Computing Science, Univ. of Glasgow, Glasgow, G12 8QQ, Scotland.
Tel: +44 141 330 6053, Fax: +44 141 330 4913,