Small Teaching: Everyday Lessons from the Science of Learning

by James M. Lang

Put as simply as possible, the retrieval effect means that if you want to retrieve knowledge from your memory, you have to practice retrieving knowledge from your memory.

In short, if you want students to do well on your individual quizzes and exams and papers and projects, you can teach them through massed or blocked practice. If you want them to learn content or skills that stretch across the entire semester, and even beyond the confines of your course, interleave.