Interleaving: mix your practice

Blocked practice is ten questions on topic A, then ten on topic B. Mixed, or interleaved, practice shuffles them. Blocked practice lets you reuse the same method on autopilot, so it feels smooth. Mixed practice forces you to first decide which method the question needs — which is exactly what an exam asks of you.

Interleaving lowers your accuracy during the session and raises it on the test. The effort of switching is the learning: each switch is a small retrieval, the same mechanism behind active recall. Judge a session by what you can still do tomorrow, not by how fluent it felt.

• Pick three or four related topics you have already studied once.
• Draw questions from all of them in a single shuffled run.
• Before answering, name the method or rule the question needs.
• Keep the mix inside one subject — mixing chemistry with French does nothing.
• Mark every miss and let it come back sooner next session.

The first time you meet a topic, block it. You cannot choose between methods you have not learned yet. Interleaving belongs to the second pass onward, once each topic makes sense on its own and the problem is telling them apart under pressure.

A shuffled deck is interleaving by default. Generate one deck per topic with PDF to flashcards, then study them in one sitting rather than one at a time, and run a mixed quiz at the end of the week. Combine it with spaced repetition — spacing decides when you review, interleaving decides what shares the session.