Blocking or interleaving: which is better for revision?

Blocking or interleaving: which is better for revision?

Revision time can be stressful. The need to remember large amounts of information that can have an impact on the next stage of students’ lives is at its peak. Years of research have found that certain revision strategies work better than others, including the likes of retrieval practice, dual coding and spacing.

Another such strategy is interleaving, the opposite of blocking, a student favourite. But is it really the best revision strategy in all cases? We had a look at the differences between the results of each strategy, to hopefully give students a better idea of what to use and when.

Interleaving vs Blocked Study

Interleaving consists of students switching between topics whilst revising in order to improve their learning. The reason behind this is that it helps students make connections between topics and forces them to think harder about which strategies need to be applied to which problems. Both of these things help improve later recall, especially in the long-term.

Blocked study, on the other hand, involves studying a topic in its entirety before moving on to another. A great example of blocking your revision is what sadly typically happens the night before a test. Some students cram all of their studying into a few hours and go over their notes for an entire module at once. Many students believe this is useful, with one survey reporting that 99% of students admit to cramming.

To make it clearer, here is what blocking and interleaving look like, in infographic form:

Graphic explaining the difference between blocking and interleaving during revision

Research shows that students overwhelmingly prefer to use blocked practice whilst studying, even though interleaving is often considered to be more efficient for learning. But is it as clear cut as it seems?

Which Revision Strategy Should Students Use?

There is a plethora of evidence supporting interleaving. For example, in one study, students were assigned to a blocked or interleaved condition and each given a set of fraction addition and fraction multiplication questions to complete. Those in the blocked condition completed all of the addition questions before moving on to the multiplication questions, and those in the interleaved group completed the questions in a randomly mixed order. Students in the interleaved condition performed almost 7% better in their final exam than those in the blocked group – suggesting that interleaving is a superior revision strategy.

However, evidence suggests that blocking may lead to greater processing fluency and is an arguably better choice if the exam is on the same day. For students who have already done the work efficiently using strategies like interleaving, this means blocking might be a way of giving their exam performance a small boost if they have some time for last-minute revision. Do keep in mind though that, contrary to popular belief, research has consistently shown that cramming all of your revision together is not an effective way to remember information in the long term. So, if students are to use blocking, it needs to be in addition to efficient revision strategies.

Final Thoughts

There are different preferences amongst students when it comes to revision techniques, including in the debate between interleaved and blocked practice. Students may be blocking their study in the belief that it will work to their advantage, despite research, as explained above, finding that not to usually be the case. Interleaving is considered to be a much more effective revision method for its ability to enhance recall and retention of information in the long term.

Unfortunately, students often don’t know what’s best for their revision, preferring easy but inefficient strategies. This suggests that it is worth introducing your students to interleaved study and its benefits and encourage them to give it a try next time they’re studying for a test. The chances of them improving their grades and discovering a more efficient way of revising are high and in their favour.

For more information on interleaving, check out these blogs:

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