What Is the Impact of Interleaving Practice and Delaying Judgments on the Accuracy of Category-Learning Judgments?

How could people enhance the accuracy of judgments for predicting math performance on an upcoming test? Research on category-learning judgments shows that their accuracy is poor for predicting performance for mathematics concepts. Based on cue-utilization theory, interleaved practice (which can enhance performance) and delaying judgments after initial study were expected to produce diagnostic cues for predicting performance and in turn improve judgment accuracy. In three experiments, we had participants practice solving problems involving (a) volumes of three-dimensional shapes (Experiments 1, 2, and 3) and (b) fractions (Experiments 1 and 3). Critically, participants either interleaved or blocked their practice of these math materials, and then judgments were made immediately after practice and after a week-long delay when participants returned for the criterion test. Judgment accuracy did not improve for the interleaved practice versus blocked practice groups, but judgment accuracy was greater when the judgments were delayed compared to when they were immediate. Public Significance Statement Does shuffling the practice of different kinds of math problems help students better judge which kinds of problems they know versus which problems they don't know? This study showed that shuffling different kinds of problems does not improve judgment accuracy but asking participants to make their judgments immediately before being tested does improve judgment accuracy. Our results can help inform education policy by helping students with the timing of their self-assessments of learning.