a) Please provide BRIEF answers to the following questions:

1. Name three different dialogue styles?

   Text-based, form-based, direct manipulation. Solutions might also refer to less common techniques including speech-based interaction or immersive virtual reality systems.

2. Give two reasons why formative evaluation must be low cost.

   Formative evaluation must be low cost because it is intended to provide feedback on the potential usability of a product while there are still sufficient resources to rectify any potential problems. It is also intended to guide numerous development decisions and so may be repeated many times during the early stages of a project.

3. What is haptic interaction?

   Haptic interaction is based around the sense of touch, in contrast to auditory or visual interaction. It makes use of force feedback devices, such as the Phantom, and gloves etc. There are more sophisticated systems based on kinesthetics and mass-market systems, such as the Sidewinder.

4. Briefly explain why predictive text-entry may not reduce errors with mobile telephones.

   Predictive text entry relies upon the accuracy of the algorithm that is used. If the system continually makes a wrong guess then the user can become engaged in lengthy repair actions that may distract them from their main task. Ultimately this may lead to more errors than might otherwise have been the case without the additional facility of the text predictions.

5. What is external consistency?

   External consistency refers to the way in which similar actions are performed on different systems. This helps users to transfer skills learnt on one system to other applications that they may use in the future and hence is important between different versions of the same product. This is in contrast to internal consistency which can ensure that similar actions are performed in similar ways throughout the same system.

[2 marks per answer, 10 marks in total]

b) Briefly explain why it is important to choose an appropriate font and point size when designing interactive software and any associated documentation.

[3 marks]

[Seen problem/bookwork]

Fonts determine the shape of different characters that are used in on-line and paper-based documentation. These shapes have different properties. For instance, sans-serif fonts lack the glyphs that help to create lines of running text. In contrast, they help words to stand out as discrete units and hence are more appropriate for on-line menus or printed headings. In contrast, serif fonts are better used for condensed prose in printed manuals. They can be used for sustained text in on-line documentation but the reproduction of the glyphs can depend upon screen resolution.

c) Minimal manuals have been proposed as a means of helping users to get started with interactive systems. Instead of relying on large documents with hundreds of pages of detailed references, users are given a short summary of the initial functionality. Briefly describe how you would design an interface so that users could gradually learn more about a system once they had become familiar with the content in the minimal manual.

[5 marks]

[Seen/unseen problem, 5 marks]

There must be some means of moving from the minimal manual to the more sustained documentation. One way of doing this is to use the minimal manual as an index into other on-line and printed documentation. For example, a brief summary on `how to enter customer details' might refer the user to a page in the main manual to `learn more about customer details'. An alternative approach is to get rid of paper-based documentation entirely, except for the initial getting started document. This implies that any remaining electronic manuals must be carefully designed. One common approach is to provide an on-line help facility that is problem based. Each section is indexed by a `how do I?' question. This is not a panacea. Instead of learning about `how do I save a file' users might need more specific information about a particular file format. The task directed indices can, therefore, be backed-up with free-text query facilities. A range of other techniques can be used to prompt the user to move beyond the minimal manual. These include daily `tips' to encourage users to learn about new aspects of the system. Tooltips can help users to learn the meanings associate with icons, menu items etc. Increasingly, companies are organising web-based FAQ's and email forums to go beyond even the maximal manuals.

d) The Johnson Corporation has won a contract to develop on-line documentation for a new device that will play digital music in a range of formats such as MP3 and WMA. The device will be sent to customers with a minimal manual. If they want to learn how to exploit more advanced features of the device then they will have to access a web site. Briefly describe how you would plan the formative evaluation of this documentation.

[7 marks]

[Unseen problem]

The formative evaluation can be complicated because it may be necessary to produce documentation well before the final device has been completed. Otherwise, this would imply a delay between the marketing of the device and the testing of necessary documentation. Ideally, it should be possible to combine the testing of early prototypes with formative evaluations of the on-line manuals. Initial users of the device could be set specific tasks to perform using the prototype, a minimal manual and early versions of the on-line documentation. This might avoid situations in which documentation is used to try and warn users of underlying usability problems. A further problem is that the on-line documentation supports more advanced functions. This implies that during the early stages of development there will also be some users who have access to a prototype system for long enough so that they can access these more advanced features. This can be difficult to arrange and sustain because these more advanced users may increasingly be drawn into the development team as their views are consulted about product development.