In this series, we dive into the realm of educational research to help you best formulate effective classroom practice
What is interleaving, and how can we ensure that pupils reap the benefits of it from our lessons and homework activities? Let’s find out.
What does the research say?
The interleaving effect is closely related to the concept of desirable difficulties and spacing. Directly contrasting to a blocking approach, whereby students repeatedly study the same material before moving on to a new subject area, interleaving allows students to practise a variety of topics in a less predictable order.
The positive effects of interleaving have been demonstrated in several studies, such as one conducted by Mayfield, Kristin and Chase (2012). In this investigation two groups of students were challenged with solving problems using the five algebraic rules about the laws of indices. One set of pupils learned the rules through a procedure akin to blocking. The other, through interleaving. In subsequent tests, the interleaved practice group outscored the blocked practice group by factor of at least 1.3, excelling both on skill-based and problem-solving questions.
Of course, curriculum design plays an important role in the successful implementation of interleaving within lessons. Schemes of work that allow for previous concepts to be seamlessly integrated into the practise of new topics lend themselves well to an interleaving approach. For example, when teaching linear equations, negative numbers, fractions, and decimals can easily be revisited by including them as coefficients or solutions.
However, as Rohrer, Dedrick and Stershic (2015) suggest, it is possible to gain the benefits of interleaving without radically changing our schemes of work. In a study on homework assignments, a group of 7th grade students were split into two, receiving either blocked or interleaved practice sheets. Blocked homework exercises were topic-based, whereas the interleaved exercises contained a mixture of questions across topics. Later, these same pupils received a review of all the content, followed by a surprise assignment. Students following the interleaving program performed significantly better on the tests.
Therefore, moving away from topic-based assignments to mixed-topic exercises could be of great benefit to pupils. However, it is also important to note that it takes time for the effects of interleaving to be felt. Remember to reassure students if initially lessons feel a little harder than usual. Indeed, we can hope that they learn to revel in the difficulty!
Interleaving topics and concepts in both lessons and homework assignments, as opposed to presenting them in blocks, is an effective and time-efficient way to improve learning. However, as the effects take a little time to show, it is important to reassure students that they’re on the right track when first introducing them to the concept.