This experiment tested alternative explanations of list method directed forgetting effects. Two word lists were studied by 135 subjects. Between lists, subjects were instructed to remember both lists , remember both lists as well as in which list words were studied , or to forget the first list and remember the second . All subjects took both recall and recognition tests with test order varied between subjects. Among subjects who took the recall test first, the forget group showed a directed (...) forgetting effect with both recall accuracy, recall typing time, and recognition reaction time measures. Contextual segregation of List 1 words by forget subjects was ruled out as a sufficient cause of the effect. Limited support was obtained for a differential rehearsal explanation of the effect. Within-group comparisons and findings of release from directed forgetting support inhibitory processes as the major cause of the directed forgetting effect. (shrink)