Interleaving Practice in Children’s Learning
- Interleaving means mixing different topics or problem types during practice, rather than completing one before starting another.
- It feels less productive than blocked practice — but produces stronger long-term retention and transfer.
- The difficulty of switching between topics is the mechanism, not a drawback.
- Interleaving is most effective once young learners have basic familiarity with each topic being mixed.
The Problem With Doing One Thing at a Time
The most common approach to practice is blocked — finishing all the questions of one type before moving to the next. It feels organised, and students tend to perform well within a block because the same method applies repeatedly. The problem is that performance during practice does not reliably predict retention later. Blocked practice produces short-term fluency that fades.
Interleaving disrupts that pattern. Instead of ten multiplication questions followed by ten division questions, students alternate between the two. Instead of practising one type of essay structure until it feels comfortable, they switch between several. The mixing creates a different kind of demand.
Why the Difficulty Is the Point
When students switch topics, they cannot carry forward the approach they just used. They have to identify what kind of problem they are facing before deciding how to solve it. This process — discrimination and selection — is exactly what is required in a real test or application, where problem types are not pre-sorted. Interleaving trains the skill of recognising what a problem is, not just how to solve a familiar one.
Researchers Robert Bjork and Elizabeth Bjork describe this as a “desirable difficulty” — a form of challenge that slows apparent progress during practice but significantly improves long-term retention and the ability to apply knowledge in new contexts. The discomfort of switching is the signal that deeper processing is happening.
What It Looks Like in Practice
Interleaving does not require elaborate planning. Students reviewing maths can alternate between topic areas rather than working through one chapter at a time. Young learners practising spelling can mix word families rather than drilling one pattern until it is mastered. Reading across different genres in the same week is a mild form of interleaving — each text requires a slightly different approach.
Interleaving is less suited to the very early stages of learning a new skill, when students need enough repetition with one approach to understand it at all. Once basic competence is established, mixing becomes more appropriate — and more useful.
The Gap Between Feeling and Performance
Students — and parents — often find interleaved practice uncomfortable because progress feels slower. Students who have just switched topics may feel uncertain in a way that blocked practice does not produce. This feeling is real but misleading. The uncertainty is a sign that the brain is doing more work, not that learning is failing.
Managing this perception matters. Learners who interpret difficulty as evidence they are not learning may disengage from the method before it has had a chance to work. Explaining that switching is supposed to feel harder — and why — makes a practical difference to how young learners tolerate it. This connects to how a growth mindset shapes a student’s response to difficulty.
Interleaving works best alongside retrieval practice — both exploit the productive difficulty of making the brain work harder to access and apply what it knows.
Firefly Ed works with children aged 3–14, applying evidence-based approaches including interleaving to build learning that transfers beyond the practice session.
Research Sources
Interleaving and Mathematics Learning
Rohrer, D., & Taylor, K. (2007). The Shuffling of Mathematics Practice Problems Boosts Learning. Instructional Science, 35, 481–498.
Taylor, K., & Rohrer, D. (2010). The Effect of Interleaving Practice. Applied Cognitive Psychology, 24, 837–848.
Desirable Difficulties
Bjork, E.L., & Bjork, R.A. (2011). Making Things Hard on Yourself, But in a Good Way: Creating Desirable Difficulties to Enhance Learning. In M.A. Gernsbacher et al. (Eds.), Psychology and the Real World. Worth Publishers.
Share your thoughts or ask something..