# Memorize faster: 5 techniques that actually work
You have read your notes four times, highlighted half the textbook, and yet when the exam comes, your mind goes blank. The problem is not your memory — it is your method. Research in cognitive psychology shows clearly that some study strategies are up to three times more effective than passive re-reading. Here are the five with the strongest scientific evidence behind them.
If you still use re-reading as your main study strategy, you are not alone — but you are wasting time. A landmark meta-analysis by John Dunlosky and colleagues (2013) evaluated ten common learning strategies and ranked re-reading among the least effective. Five techniques, however, stand out. We break them down here, with the studies that support them and concrete examples you can apply tonight.
To understand in detail why re-reading fails, check out our article Re-reading your notes is useless: here is what science says.
1. Active recall: test yourself instead of re-reading
The principle is simple: instead of re-reading your notes, close them and try to retrieve the information from memory. Researchers call this the testing effect — the finding that the very act of testing strengthens the memory trace far more than passive re-exposure.
What the science says. Henry Roediger III and Jeffrey Karpicke (Washington University) demonstrated in 2006 that students who tested themselves after a single reading retained significantly more information one week later than those who had re-read the text four times. The gap widened over time: the longer the delay, the greater the advantage of active recall (Roediger & Karpicke, 2006).
In practice. After reading a biology chapter, set your notes aside and write down everything you remember on a blank sheet of paper. The gaps you discover are exactly what you need to revisit. You can also create flashcards or use quizzes: the key is to force your memory to produce the information, not merely recognize it.
Dunlosky et al. (2013) rank practice testing as one of only two strategies with "high utility" in their reference meta-analysis (Dunlosky et al., 2013).
2. Spaced repetition: study at the right time
Cramming the night before the exam is the worst possible timing strategy. Spaced repetition involves spreading your review sessions over time, with increasing intervals between each review of the same material.
What the science says. The spacing effect is one of the most robust findings in memory psychology. Kornell and Bjork (2008) showed that even when students felt they learned better in massed sessions, their actual performance was superior with spaced sessions (Kornell & Bjork, 2008). Dunlosky et al. (2013) also rank distributed practice as "high utility."
In practice. If your exam is in three weeks, do not review chapter 5 three times on the same day. Review it today, then in two days, then in five days. Each time, the effort of recall will be harder — and it is precisely this difficulty that consolidates long-term memory.
To dive deeper into this technique, see our complete guide on spaced repetition.
3. Elaborative interrogation: ask "why?"
Reading that "the mitochondrion is the powerhouse of the cell" is not enough. Ask yourself why that is the case. Elaborative interrogation involves generating explanations for the facts you are learning by connecting them to what you already know.
What the science says. Dunlosky et al. (2013) rate this technique as "moderate utility." It works because it forces deeper processing of information: by seeking the "why," you create connections between the new concept and your existing knowledge, which multiplies the retrieval paths in memory. Research by Pressley, McDaniel, and their collaborators has shown that students who questioned the reasons behind facts retained 20 to 30% more than those who simply read them.
In practice. Studying constitutional law? Instead of just memorizing that "the Constitutional Council can be referred to by 60 deputies or 60 senators," ask yourself: Why this threshold of 60? What problem does it solve? What would be the consequences of a different threshold? This habit transforms passive memorization into active understanding.
4. Interleaving: mix your subjects
The natural instinct is to study one topic thoroughly before moving on to the next. Interleaving proposes the opposite: alternate between several subjects or problem types within the same session.
What the science says. Kornell and Bjork (2008) demonstrated this effect in the domain of learning artistic styles: participants who alternated between different painters identified styles more accurately than those who studied one painter at a time. The same principle applies to mathematics, science, and law. Interleaving forces the brain to discriminate between concepts, which strengthens the ability to choose the right strategy when facing a new problem.
In practice. Rather than doing 20 derivative problems followed by 20 integration problems, mix them: derivative, integral, differential equation, derivative, integral... It feels more uncomfortable, and that is normal — research shows that students find interleaving harder, but their test scores are better.
5. Concrete examples and dual coding: see it and say it
The final technique combines two complementary principles. First, anchor abstract concepts in concrete examples. Second, use dual coding — combining verbal and visual representations to create two memory traces instead of one.
What the science says. Allan Paivio's dual coding theory (1970s) shows that information encoded in both verbal and visual form is better retained because it benefits from two independent retrieval paths. Dunlosky et al. (2013) also highlight that concrete examples help make abstract ideas more manageable in working memory.
In practice. Studying economics? Instead of just re-reading the definition of price elasticity, draw a supply-and-demand graph, annotate it with a real-world example (gas prices in your country), and state the definition in your own words. You now have three anchors in memory: the visual diagram, the concrete example, and your personal reformulation.
How to combine these techniques daily
The real power comes from combining them. Here is what a 45-minute study session could look like:
| Time | Activity | Technique |
|---|---|---|
| 0-5 min | Free recall on yesterday's chapter | Active recall |
| 5-15 min | Quiz on 3 different topics in alternation | Interleaving + Active recall |
| 15-25 min | Read a new chapter with "why?" questions | Elaborative interrogation |
| 25-35 min | Create visual diagrams + concrete examples | Dual coding |
| 35-45 min | Spaced review of last week's cards | Spaced repetition |
To avoid classic revision mistakes, also check out our article on the 5 mistakes most students make.
Wizidoo: these techniques, automated
If you want a tool that applies these principles without you having to organize everything yourself, Wizidoo integrates active recall, spaced repetition, and interleaving directly into its workflow. You import your course material (photo, PDF, or text), and the app generates adaptive quizzes that target your weak spots, with a mastery percentage per concept that evolves with each session. The first course is free — you can try it on the App Store and judge for yourself whether you feel the difference.
FAQ
How long does it take to memorize a course using these techniques?
It depends on the density of the course and your familiarity with the subject. But research shows that using active recall and spaced repetition can reduce total study time by 30 to 50% compared to re-reading, while retaining more in the long term.
Do these techniques work for all types of courses?
Yes. Active recall and spaced repetition have been tested on highly varied content: language vocabulary, anatomy, law, mathematics, history. Dunlosky et al. (2013) emphasize that these two techniques are effective regardless of material type, learner age, or context.
Should I completely stop re-reading?
Not necessarily. A careful first reading is still necessary to discover the content. What you should avoid is using re-reading as your main revision strategy. After a first reading, move immediately to active recall.
Does interleaving work if I only have one exam on one subject?
Yes, because even within a single subject, you can interleave different chapters or problem types. For example, in math, alternate between geometry, algebra, and analysis instead of reviewing each area in a block.
How do I know if I am applying these techniques correctly?
The best indicator is perceived difficulty. If your study session feels easy and smooth, you are probably in passive re-reading mode. If it requires mental effort — if you make mistakes, if you hesitate — that is a good sign. This is what Bjork calls "desirable difficulties": effort produces learning.
References
- Dunlosky, J., Rawson, K. A., Marsh, E. J., Nathan, M. J., & Willingham, D. T. (2013). Improving Students' Learning With Effective Learning Techniques. Psychological Science in the Public Interest, 14(1), 4-58. https://doi.org/10.1177/1529100612453266
- Roediger, H. L., & Karpicke, J. D. (2006). Test-Enhanced Learning: Taking Memory Tests Improves Long-Term Retention. Psychological Science, 17(3), 249-255. https://doi.org/10.1111/j.1467-9280.2006.01693.x
- Kornell, N., & Bjork, R. A. (2008). Learning Concepts and Categories: Is Spacing the "Enemy of Induction"? Psychological Science, 19(6), 585-592. https://doi.org/10.1111/j.1467-9280.2008.02127.x