The development manager of a website for online book-buying has asked you to carry out a heuristic evaluation of its usability. He has specifically proposed the three heuristics listed below.

1. There should be between five and nine navigation options on each page.

2. There should be a good match between the navigation buttons and the users goals.

3. It should be easy for users to change their plans.

1. Has the manager misunderstood heuristic evaluation? Briefly justify your answer.
2. Please comment on the above three heuristics suggested by the manager. For each of the proposed heuristics your comments should include:
3. any theoretical justification for (or against) this heuristic
4. any additional evaluation steps that might be required in applying it and the likely impact of such evaluation on the system design