Does the interleaving effect extend to unrelated concepts? Learners’ beliefs versus empirical evidence.

When learning new information, should students focus on studying 1 concept at a time or should they alternate studying between different concepts? Recent research shows that students should mix up or interleave the study of different concepts, particularly when the concepts are related or hard to discriminate (Carvalho & Goldstone, 2015). But students rarely study only 1 course, so how should the study of unrelated courses be sequenced? Should the study sessions be blocked by course to avoid unproductive juxtapositions or be interleaved across different courses because it inherently involves spaced practice, which is also effective for learning? In Experiments 1 and 2, we explored how students construct their study sessions by using hypothetical scenarios. Finally, in Experiment 3, we experimentally manipulated the study sequence of related concepts within 2 unrelated domains (i.e., physics and statistics). Given only 1 level to schedule (related modules or unrelated courses; Experiment 1), students chose to block related modules but to interleave unrelated topics—even though the literature suggests the related concepts are more likely to benefit from interleaving. Given 2 levels to schedule (concepts and domains; Experiment 2), students chose to interleave everything—even though empirical data from Experiment 3 suggests that the optimal schedule involves interleaving at either the concept or the domain level, but not both or neither. (PsycInfo Database Record (c) 2021 APA, all rights reserved) Educational Impact and Implications Statement—A recent spate of research has shown that mixing up (i.e., interleaving) the study and practice of different concepts (e.g., ABCABCABC) leads to better concept learning than does focusing on only 1 concept at a time (AAABBBCCC), leading to many calls to incorporate interleaving into instruction. There are, however, still large gaps in the empirical evidence about when interleaving is effective and in this present series of studies, we focus on one particular gap: How should learners sequence their study when they have multiple concepts embedded within different domains—should interleaving occur at only the concept-level, at the domain-level, or both? We examined and found discrepancies between how students choose to sequence their study sessions and how they should sequence study sessions. Empirically, the optimal sequence involved interleaving at either the concept or the domain level, but not both or neither, demonstrating that careful consideration needs to be given to how interleaving is implemented in the broader educational context.