When students learn related topics in a subject like math or a language, they may benefit from using a technique called “interleaving.”  Also called mixed or varied practice, “Interleaving is a process in which students mix multiple subjects or topics while they study in order to improve their learning. For instance, if learning 2 or more related topics, like multiplication and division, instead of devoting time and energy on “blocked” or exclusive practice on only one topic at a time, include both topics in the same session.  

Interleaving practice was first applied to motor skills in sports as early as 1986.  For example, in tennis, instead of repetitive work on skill A (forehand) one session and skill B (backhand) in a separate session, which is the method in “blocked” or “mass” practice, the player using the interleaving technique would practice both skills A & B in one practice session. The mixed practice resulted in more effective results than the block learning. 

“In 2003, one of the first studies to examine interleaving outside of sports found that using it to train medical students produced more accurate electrocardiogram diagnoses than blocking.”  More recent research on interleaving has recently reached middle and high schools and appears to benefit some subjects like math and language. The practice of mixing up  learning can avoid confusion between topics that are  closely related like similar vocabulary words.   It has been shown to provemore effective than blocked practice for developing the skills of categorization and problem solving; interleaving also leads to better long-term retention and improved ability to transfer learned knowledge.”  

Whilemassed (blocked) practice remains an important component of initial learning, interleaving can be especially valuable when used at strategic intervals to solidify deeper learning.” Reviewing previous concepts regularly (spacing) can solidify learning and is also a useful part of interleaving, which works best when the learning material is neither too similar or too different.  Mixing up the two strategies may be an effective way of providing variety for an active learning environment.