exercises

7. design rules

EXERCISE 7.10 [extra - not in book]

Can principles be used to prove the usability of a system? Justify your answer.

answer available for tutors only

They can't prove it but can help demonstrate it. Since principles of software ergonomics are ill defined, could argue that usability principles offer a means of defining software usability. For example:

  • Predictability: support for the user to determine the effect of a future action based on past interaction.
  • Consistency: Likeness in input/output behaviour arising from similar situations or actions.
  • Generalizability: support for the user to extend knowledge of a specific interaction within and across applications.

If a system supports these principles it is more likely to be usable than if it does not.

Other exercises in this chapter

ex.7.1 (ans), ex.7.2 (ans), ex.7.3 (open), ex.7.4 (ans), ex.7.5 (ans), ex.7.6 (ans), ex.7.7 (tut), ex.7.8 (tut), ex.7.9 (open), ex.7.10 (tut), ex.7.11 (tut), ex.7.12 (tut), ex.7.13 (tut)

all exercises for this chapter