Timing of Testing Affects Earwitness Memory

The present experiments investigated how interpolated testing and postevent misinformation affected earwitness memory. We examined how the number of tests and when tests occurred affected memory for an overheard event and source monitoring. Across three experiments, participants overheard a crime (i.e., the witnessed event), heard a news report summarizing the crime (postevent information), took a cued-recall test, and lastly, took a source-monitoring test. Experiment 1 compared three groups: repeated cued-recall test, repeated listen, single cued-recall test. Participants in the interpolated test group received a test after the witnessed event and again after the postevent information. Participants in the repeated listen group heard the witnessed event, and immediately relistened to the event before being presented with the postevent information. In Experiment 2 and 3, we varied the retention intervals between the witnessed event and the postevent information in a repeated test context. Our findings suggest that when participants took a test before presentation of the postevent information, they were less accurate on a final cued-recall test of the witnessed event. Importantly, the timing of the first test in relation to the witnessed event and postevent information differentially affected memory for the witnessed event and source monitoring of event and postevent details.