by Vivienne Trulock
Retrospective Testing (RT) simply entails reviewing the video recording of the user test (think aloud / Co-discovery Learning sessions) with the users present and asking them to explain their behaviour during the test. This should be done as soon as possible after the test
Retrospective Testing is useful if there is an important issue that the evaluators need to understand correctly, or if the user has behaved in a way that the evaluators cannot understand. RT may not be needed in all cases but is a useful safety net. It may not be necessary to review the whole of the recording.
Depends on ease of analysis of previous test. Potentially 0, or 6 – those users where behaviour and thought processes were least easily analysed, or those who had a particular problem needing further understanding.