Comparing the testing effect under blocked and mixed practice: The mnemonic benefits of retrieval practice are not affected by practice format.

The act of retrieving information modifies memory in critical ways. In particular, testing-effect studies have demonstrated that retrieval practice (compared to restudy or to no testing) benefits long-term retention and protects from retroactive interference. Although such testing effects have previously been demonstrated in both between- and within-subjects manipulations of retrieval practice, it is less clear whether one or the other testing format is most beneficial on a final test. In two paired-associate learning experiments conducted under typical testing-effect conditions, we manipulated restudy and test trials using either blocked or mixed practice conditions while equating other factors. Retrieval-practice and restudy trials were presented either separately in different blocks (blocked practice) or randomly intermixed (mixed practice). In Experiment 1, recall was assessed after short and long delay intervals; in Experiment 2, the final memory test occurred after a short delay, but with or without an interfering activity before the final test. In both experiments, typical testing effects emerged, and critically, they were found to be unaffected by practice format. These results support the conclusion that testing effects are robust and emerge to equal extents in both blocked and mixed designs. The generality of testing effects further encourages the application of retrieval practice as a memory enhancer in a variety of contexts, including education.