Why does guessing incorrectly enhance, rather than impair, retention?

The finding that trying, and failing, to predict the upcoming to-be-remembered response to a given cue can enhance later recall of that response, relative to studying the intact cue–response pair, is surprising, especially given that the standard paradigm (e.g., Kornell, Hays, & Bjork, 2009 ) involves allocating what would otherwise be study time to generating an error. In three experiments, we sought to eliminate two potential heuristics that participants might use to aid recall of correct responses on the final test and to explore the effects of interference both at an immediate and at a delayed test. In Experiment 1 , by intermixing strongly associated to-be-remembered pairs with weakly associated pairs, we eliminated a potential heuristic participants can use on the final test in the standard version of the paradigm—namely, that really strong associates are incorrect responses. In Experiment 2 , by rigging half of the participants’ responses to be correct, we eliminated another potential heuristic—namely, that one’s initial guesses are virtually always wrong. In Experiment 3 , we examined whether participants’ ability to remember—and discriminate between—their incorrect guesses and correct responses would be lost after a 48-h delay, when source memory should be reduced. Across all experiments, we continued to find a robust benefit of trying to guess to-be-learned responses, even when incorrect, versus studying intact cue–response pairs. The benefits of making incorrect guesses are not an artifact of the paradigm, nor are they limited to short retention intervals.