The testing effect with free recall: Organization, attention, and order effects

Memory retrieval not only reveals but can also change memory, as shown by direct and indirect (e.g., forward) testing effects. Three experiments examined the testing effect with free recall, with respect to attention, organization and forward testing effects. In Experiment 1, participants learned two categorized word lists, one followed by retrieval practice and the other by restudy; memory for both lists was assessed on a final free recall test two days later. Retrieval practice and restudy were conducted under full attention (FA) or divided attention (DA). Final recall was significantly diminished by DA in the restudy but not retrieval condition, indicating that the encoding consequences of retrieval are relatively resistant to distraction. However, a negative testing effect was found on final recall (in the FA condition). Experiments 2 and 3 implemented a between-subjects version of the experiment (FA condition only) in which both learning blocks were in the retrieval or restudy condition. Final recall now exhibited a positive testing effect. Analyses of the order of learning blocks revealed strong forward-testing effects in which the study list following the retrieval block produced superior final recall, a benefit accruing to the restudy condition in the within-subject design (Experiment 1) and to the retrieval condition in the between-subjects design (Experiments 2 and 3). In contrast, no direct testing effects were found on the first list, a result analyzed in terms of prior research that often conflated forward and direct testing effects. Finally, retrieval practice generally did not impact organization (as measured by category clustering on the final recall test), indicating that the organization effect found in earlier research may not be readily replicated.