Study for now, but judge for later: delayed judgments of learning promote long-term retention

Delayed judgments of learning (JOL) are assumed to be based on covert retrieval attempts. A common finding is that testing memory during learning improves later retention (i.e., the testing effect), and even more so than an equivalent amount of study, but only after a longer retention interval. To test the assertion that also delayed JOLs improve memory, the participants either studied Swahili-Swedish word pairs four times, or they both studied (two times) and performed delayed JOLs (two times) alternately. Final cued recall test were given after either five minutes or one week. Results showed a reliable learning-group by retention-interval interaction, with less forgetting in the group that alternated between studying and making JOLs. The results are discussed in relation to the self-fulfilling prophecy account of Spellman and Bjork (1992), and in terms of study advice, the results further underscore the importance of delaying JOLs when studying and evaluating one's ongoing learning.