UC Davis

Memory retrieval is well known to modify retention of not only retrieved material, but also related, non-retrieved material. This dissertation consists of two manuscripts that investigated retrieval phenomena in the learning of foreign language vocabulary and science education material. The testing effect–the retention benefit of practicing retrieval compared to studying–and the pretesting effect–incorrectly guessing a target before learning compared to studying–demonstrate the advantages of retrieval-based learning, but no extant theories have accounted for both of these effects. In Chapter 1, we investigated an error-driven learning account whereby retrieval-based learning serves to “stress test” the memory system, allowing it to learn to better predict a target from a cue, whereas in studying, there is no opportunity for the system to form a prediction. We predicted that inserting a small temporal “gap” between a foreign language word and its English translation should enhance retention when compared to simultaneous, “no gap,” presentation. In four experiments (N = 287) we consistently observed that “gap” conditions benefitted retention compared to “no gap” conditions, which supports the error-driven learning account. We observed that a gap as short as 600 ms benefitted retention one day later, one minute later, and in a pure list design. In Chapter 2, we investigated the sequalae of retrieval practice for non-practiced educational science text material. Some evidence suggests that retrieval practice of main ideas would lead to greater retention of non-practiced information, whereas other evidence suggests that retrieval practice of peripheral information would lead to impaired retention of non-practiced information, when compared to a control group that did not practice retrieval. In two experiments (N = 360) we observed robust testing effects, but we did not observe robust differences in non-practiced material, suggesting that the kind of focal retrieval practice used here has focal effects on science material retention.