Interleaving for A-level revision: mix topics, don’t block them
Why switching between subjects or question types beats drilling one thing for hours
Blocked practice feels easier: you do ten elasticity questions, then ten market failure questions, then ten essays. Interleaved practice feels harder: you mix them up so each question forces you to choose the right approach. Research shows that harder-feeling practice produces stronger memory and better transfer to new questions — exactly what A-level papers demand.
If every question in a session feels the same, you’re not practising exam conditions. Exams never tell you which technique to use — you have to recognise it.
What the research shows
Rohrer et al. (2019) ran a large randomised trial with dozens of classes: students who used interleaved maths practice scored far higher on a later test than those who used blocked practice (effect size d ≈ 0.83). A systematic review of interleaving (Firth et al., 2021) found benefits for memory and for solving new problems, including in science. Physics homework studies report large gains when practice is interleaved rather than blocked. Evidence: https://psycnet.apa.org/record/2019-26066-001 — https://bera-journals.onlinelibrary.wiley.com/doi/full/10.1002/rev3.3266 — https://pmc.ncbi.nlm.nih.gov/articles/PMC8589969/
How to interleave for A-levels
- In one session, mix 2–3 related topics (e.g. two biology units, or two economics themes) instead of finishing one completely first
- Use past-paper questions from different topics in random order, or shuffle a question bank
- Alternate flashcard decks or spec sections every few cards
- Once a week, do a ‘mash-up’: 30 minutes of questions drawn from the whole year so far
- Expect it to feel slower and messier than blocked practice — that difficulty is the point
Pair interleaving with spaced repetition and active recall. Together they cover most of what cognitive science recommends for durable A-level learning.