In Experiment 4, we showed that when retrieval success is boosted, both overt and covert retrieval practice benefit memory more than restudying the items. This was true even though re- studying the items still potentially provided an advantage; in the restudy condition all subjects were reexposed to 100% of the items, whereas in the overt retrieval practice conditions subjects produced 72% of items. In this experiment, subjects in the covert retrieval condition performed better on the retention test than those in the overt retrieval conditions. However, in light of the absence of an interaction, it is plausible that this came about due to assignment of subjects to each of the two between-subjects con- ditions. Note that subjects in the restudy condition combined with covert retrieval performed better than those in the restudy condi- tion combined with the overt retrieval condition, despite the fact that the study trials were exactly the same in the two conditions. It is also possible that covert retrieval practice truly produces a recall advantage relative to overt retrieval under certain circumstances. We discuss these possibilities in the General Discussion.