Interleaving
Mix topics in one session — don’t block them.
What the Research Says
Most students revise by blocking — an hour on markets, an hour on elasticity, an hour on inflation. It feels productive and the topic seems clear by the end. Interleaving is the opposite: you jump between topics inside a single session. It feels worse at the time, and you’ll make more mistakes. But when the real exam arrives, you will be dramatically better at knowing which concept to apply — and that is usually the hardest part of any economics question.
Evidence Base
| Study | Finding | Impact |
|---|---|---|
| Rohrer & Taylor (2007) | Students who interleaved topics scored 43% higher on delayed tests than blocked-practice students. | Same time spent — huge difference in exam performance. |
| Birnbaum et al. (2013) | Interleaved learners felt LESS confident during practice but performed BETTER in the test. | If revision feels too easy, interleave. |
| Bjork & Bjork (2011) | Desirable difficulties — including interleaving — create durable long-term learning at the cost of short-term performance. | Short-term struggle is the price of long-term gain. |
| Taylor & Rohrer (2010) | Benefit was largest when topics looked superficially similar — students learnt to DISTINGUISH them. | Most useful where students confuse similar concepts. |
Step-by-Step Method
- 1Pick 3–5 related topics — topics that share a paper, a theme, or a question type. Similar enough that students confuse them.
- 2Make a mixed question set — 10–15 questions drawn randomly from all the topics. Don’t tell yourself which topic each question belongs to.
- 3Attempt each question cold — first step is identifying what’s being asked. That identification is the skill you’re training.
- 4Mark after every question — note which topic each one was. Pay attention to mis-identifications — those are the highest-value gaps.
- 5Rebuild a new mixed set tomorrow — same topics, different questions. Different order. Over time, misclassifications drop.
- 6Expect to feel worse than blocked practice — that’s the right feeling. Your exam self will thank you.
Create a 15-question mixed set spanning Paper 1 microeconomics topics: price elasticity of demand, price elasticity of supply, income elasticity, shifts in demand versus movements along the demand curve, and market failure types (externalities, public goods, information failure). Because these all relate to markets and price mechanisms, exam questions can sound deceptively similar. Working through them in random order forces you to identify whether a question is asking about a formula, a diagram shift, or a type of market failure — a distinction that separates 3-mark definitions from 6-mark analysis answers.
In the final weeks before the exam, interleave Paper 1 questions (e.g. “Explain why a subsidy on solar panels could help correct a positive externality”) with Paper 2 questions (e.g. “Analyse the likely effects of a rise in interest rates on the rate of inflation”). Switching between microeconomics and macroeconomics in one sitting closely mirrors the actual exam experience, where students must identify which framework applies before they can answer correctly.
Common Pitfalls
- Random, not related. Interleaving Economics with History is just subject-switching. Interleave WITHIN Economics — related concepts that students confuse.
- Giving up when it feels hard. The discomfort is the signal that it’s working. Don’t revert to blocked practice because interleaving feels slow.
- Labelling the topic at the top of each question. Defeats the point — the identification IS the training.
- Using it too early in learning. You need baseline familiarity with each topic first. Interleaving is for consolidation, not first exposure.
When to Use This
Once you’ve covered a handful of related topics — usually partway through a term — start weaving them into mixed practice sessions. Very useful in the final 8–10 weeks before exams when you’re moving from learning to applying. Full past papers are the ultimate interleaving exercise, because they force you to identify question types cold.