Additional Theoretical Design Issues

In addition to the consideration of Norman's principals of effective design, we referred to Schneiderman's eight golden rules for interface design, specifically concerning the "i-browse" information hub:

1. Consistency

The action sequence and layout of the "i-Browse" i-agent is very simple, with only three limited fundamental actions so as not to confuse the user. These consist of the question state, an answer state and a confused state, for when the user has requested information which the i-agent does not understand.
Similarly the command use of the i-agent is very simplistic, with basic terminology being used in order to active the hub, direct it and close session.

These features in turn, create a consistent, easy to understand and learnable interface for the user.

2. Shortcuts for frequent users

As the i-agent will be intuitive, it will recognize returning users and make suggestions based on their previous usage, namely short-cuts to frequently access information and suggestions for further points of interest. This will in turn generate efficient usage and increase the likelihood of users returning to the system.

3. Feedback

With the i-agent resembling human form, formative feedback will be clearly visibly and audible to the user, via the use of the three actions mentioned above.

4. Closure dialogues

Again, as the i-agent resembles human form, the closure dialogues informing the user when they have completed a task, will be clear.

5. Error prevention and handling

Error prevention has been taken into account via constraining the choices of the user by making all actions of, interactions with and feedback mechanisms for the i-agent clear and visible to the user.

6. Easy reversal of actions

This also links to error prevention mechanisms above. However, i-agent has been designed so that the user can undo any action they have made and/or return to the home screen via a simple command.

7. Internal control mechanisms

While the i-agent is an intuitive system, the user maintains control at all times and has the ability to select and deselect the level of information they require.

8. Keeping displays simple

This again links to consistency above and has been explained.

Source: Dix, A., Finlay, J., Abowd, G.D. and Beale, R. (2004): Human-Computer Interaction. Third Edition. London: Prentice Hall Publishers