SIXTH FORM: What is interleaving?

Interleaving refers to the benefits of sequencing learning tasks so that similar items – two examples of the same concept, say – are interspersed with different types of items rather than being consecutive.

This results in a more variable and challenging task but is associated with benefits in terms of memory.

Interleaving tends to be contrasted with classroom tasks that are scheduled in blocks of similar items, with the latter termed a ‘blocked’ arrangement. For example, in Figure 1, item ‘A’ is interleaved with items ‘B’ and ‘C’.

Many of you will be used to revising one concept at a time – known as blocking. Most textbooks are also organised in this way. A chapter on one idea is usually followed by a series of questions on that idea. However, there is some research (mainly focusing on maths teaching) in support of interleaved revision.

When students encounter a set of concepts (terms or principles) that are similar in some way, they might mistake one word for another word with a similar spelling (e.g. mitosis v meiosis). It is reported that these kinds of errors occur more frequently when all exposures to one of the concepts are grouped together. For example, when all the questions in an assignment or a lesson are devoted to one concept.

Some evidence has shown that if you interleave different concepts together, e.g. follow a question on one concept by a question on another concept, this can produce better assessment scores.