Memory accuracy and confidence for details of an event were investigated as a function of three question forms (open-ended, true-false (T-F) and four-alternative-forced-choice (4-AFC) questions), type of content (action vs. descriptive details) and centrality of information (central vs. peripheral). Sixty-two undergraduates were shown a film of a robbery, then answered 32 questions about the film using a questionnaire in one of the three question forms. Open-ended (74.1%) and T-F questions (73.0%) led to significantly more correct answers than 4-AFC questions (66.5%). Accuracy was higher for central than peripheral information, and higher for action details than for descriptive details. Central action details were remembered better than peripheral action details whereas centrality made no difference for descriptive details. Moreover, type of content and centrality of information had different effects depending on question form. Confidence in correct answers with open-ended questions was lower than with T-F and 4-AFC questions. Across question forms, witnesses were much more confident with correct than incorrect answers, except for central action details. The discussion focuses on differences between recall and recognition and their implication for confidence with different question forms. Copyright (C) 2004 John Wiley Sons, Ltd.
