Whether Interleaving or Blocking Is More Effective for Long-Term Learning Depends on One’s Learning Strategy

Grouping information into categories enables us to learn, integrate, and apply new information. Presenting items from different categories sequentially (i.e., interleaving) is often more effective than presenting items from a single category sequentially (i.e., blocking), particularly when evaluating learning using memory-based tests. However, blocking can be more effective than interleaving for rule-based learning. Research has investigated optimal sequence (interleaving vs. blocking) for category learning when participants can either memorize or find rules, finding an interaction between learning strategy and sequence; that is, when memorizing, interleaving is more effective than blocking for classifying based on similarity, but when trying to find a rule, blocking is more effective than interleaving for classifying based on the rule. The goal of the present experiments was to replicate and extend this finding by examining transfer immediately after learning and then at a delay of about 48 h. The present results replicate the interaction between sequence and strategy, and show that the pattern persists over a delay. The results also suggest that some rule-based learning may be more resistant than memory-based learning to forgetting. These findings have educational implications for structuring learning as a function of strategy or learning goals.