- There are three styles of interviews: structured, semi-structured and unstructured.
- Interview questions can be open or closed. Closed questions require the interviewee to select from a limited range of options. Open questions accept a free-range response.
- Many interviews are semi-structured. The evaluator has a predetermined agenda but will probe and follow interesting, relevant directions suggested by the interviewee. A few structured questions may also be included, for example to collect demographic information.
- Structured and semi-structured interviews are designed to be replicated. Focus groups are a form of group interview.
- Questionnaires are a comparatively low-cost, quick way of reaching large numbers of people.
- Various rating scales exist including selection boxes, Likert, and semantic scales.
- Inspections can be used for evaluating requirements, mockups, functional prototypes, or systems.
- Five experts typically find around 75% of the usability problems.
- Compared to user testing, heuristic evaluation is less expensive and more flexible.
- User testing and heuristic evaluation often reveal different usability problems.
- Other types of inspections include pluralistic and cognitive walkthroughs.
- Walkthroughs are very focused and so are suitable for evaluating small parts of systems.
From: Preece, J., Rogers, Y., Sharp, H. (2002), Interaction Design: Beyond Human-Computer Interaction, New York: Wiley, p. 424