Participants

One of the most important parts of the useability test plan is a clear indication of the number and types of testing participants.
- Use a screening questionnaire to find the right types of people as test participants.

The number of participants is frequently dictated by the budget and time allocated for the useability test.
- If an early prototype is being tested, only a few participants are needed to uncover the most serious problems.
- If the useability test needs statistical numbers to identify real differences when they exist, then a large sample size is needed.