Study Techniques That Actually Work: Spaced Repetition, Active Recall and More

Most students study the way they were taught: reread the textbook, highlight the important lines, and copy out notes. It feels productive, but the research says it mostly is not. The two techniques with the strongest evidence — testing yourself from memory, and spacing your reviews — are also the two students use least.

This guide explains what the evidence actually says, how each technique works, and how to build a study routine around them, whether you are preparing for school exams, university finals, or a professional qualification.

What the research says

The most cited summary is a 2013 review by John Dunlosky and four colleagues, published in Psychological Science in the Public Interest. The authors reviewed the evidence for ten common techniques, looking at how well the benefits held up across different learners, materials and test types.

Their ratings were:

• High utility: practice testing (active recall) and distributed practice (spaced repetition). Only these two earned the top rating.
• Moderate utility: elaborative interrogation (asking “why is this true?”), self-explanation, and interleaved practice (mixing different types of problems).
• Low utility: summarisation, highlighting, the keyword mnemonic, imagery for text learning, and rereading.

A later meta-analysis by Donoghue and Hattie (2021), covering 242 studies and more than 169,000 participants, confirmed the same pattern.

Highlighting and rereading can help you get familiar with material the first time you meet it. But if your goal is to remember something weeks later in an exam, they are among the weakest tools you can choose.

Technique 1: Active recall (practice testing)

Active recall — also called retrieval practice or self-testing — means pulling an answer out of your memory instead of looking at it. Ask yourself a question, try to answer it without checking, and only then look at the correct answer.

The classic demonstration comes from a 2006 study by Henry Roediger and Jeffrey Karpicke. Students read prose passages and then either reread them or took recall tests on them, without feedback. On a final test five minutes later, the rereading group did slightly better. But on final tests two days and one week later, the students who had tested themselves remembered substantially more. In one version, students who read a passage once and then recalled it three times remembered 61% of it a week later, while students who read it four times remembered 40%.

A 2021 review of 50 classroom experiments with more than 5,000 students found that 57% of the effects of retrieval practice were medium or large. And in a randomised study of medical residents, repeated testing produced 39% correct on a final test after six months, compared with 26% for repeated studying.

Why does it work? Every time you retrieve something from memory, you strengthen that memory — and you find out what you do not know. Rereading creates a fluency illusion: the material feels familiar because you have just seen it, so you think you know it.

How to use active recall

• Turn notes into questions. After a lecture or a chapter, close the book and write down questions the material should let you answer. Then answer them from memory.
• Use flashcards, but properly. Look at the question side first, answer out loud or on paper, and only then flip the card. If you flip the card before answering, you are rereading.
• Do past papers under exam conditions. Real exam questions, a time limit, and no notes. Mark your answers honestly, then study what you got wrong.
• Explain it without looking. Close your notes and explain a topic out loud, as if teaching a friend. Every point you cannot explain is a gap to fix.
• Test before you restudy. Start by testing yourself on last week’s material, and only then open your notes to fill in what you missed.

Technique 2: Spaced repetition (distributed practice)

Spaced repetition is about when you study, not how. Instead of cramming everything into one long session, you review the same material several times with gaps between sessions, and the gaps grow longer as the material sticks.

The spacing effect is one of the most replicated findings in psychology. A 2006 meta-analysis by Nicholas Cepeda and colleagues reviewed 839 assessments of spacing in 317 experiments from 184 articles, and found that spaced practice beat massed practice, and that the best gap grew as the time until the test grew. A 2008 study by the same team, testing more than 1,350 people over gaps of up to three and a half months, found the same pattern over much longer timescales.

A useful rule of thumb is to space reviews at roughly 10% to 20% of the time until the test. If your exam is in ten days, review after about one to two days. Return to material just as you are starting to forget it.

How to use spaced repetition

• Plan backwards from the exam date. Schedule three or four reviews of each topic before the exam — for example, one day later, three days later, one week later, and two weeks later.
• Mix short sessions with longer gaps. Several short sessions spread over days beat one long session on the night before.
• Combine it with active recall. The strongest combination in the research is retrieval plus spacing: answer questions from memory, then repeat the ones you missed at growing intervals. Spaced repetition without recall is just rereading on a schedule.

Technique 3: Interleaved practice

Interleaved practice means mixing different types of problems or topics in a single study session, instead of doing one block of one type and then moving on. Dunlosky and colleagues rated it moderate utility.

If you are studying maths, for example, do not do twenty identical algebra questions and then twenty identical geometry questions. Mix them up, so each question forces you to work out which method to use — which is exactly what an exam asks you to do.

Interleaving feels harder than blocked practice, and your scores during practice may be lower. That is normal — the difficulty is what makes the learning stick.

What to stop doing (or do less of)

Rereading and highlighting have a place: the first time you meet new material, reading it through and marking what matters helps you understand it. The mistake is stopping there.

If your whole revision plan is reread, highlight, rewrite notes, and reread again, you are spending most of your time on the techniques the research rates lowest. Read the material once, then spend the rest of your time testing yourself on it and returning to it at spaced intervals.

Rewriting notes is mostly transcription. Turning your notes into questions, and answering those questions from memory, is the same time spent far more effectively.

A simple weekly study plan

Here is a routine that puts the evidence together:

1. After each class or chapter (same day): Spend 10 to 15 minutes writing questions from the material, then answer them from memory.
2. The next day: Test yourself on yesterday’s material before starting anything new.
3. Two to three days later: Test yourself again, mixing in questions from earlier topics.
4. One week later: A short test on the whole week’s topics.
5. Before the exam: Do past papers under timed conditions, and use your results to target the remaining gaps.

Study in focused blocks of 25 to 50 minutes with short breaks between them. Short, regular sessions fit naturally with spacing, and are easier to sustain than marathon cramming sessions.

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Related reading on WorldForbes

• Scholarships Explained: How to Find Them, Apply, and Avoid Scams — how to fund the course you are studying for.
• Online Degrees Explained: Are They Respected, and How to Check Accreditation — check a course’s accreditation before you enrol.
• Is ChatGPT Free? What the Free Tier Includes in 2026 — AI tools can help you generate practice questions, but check their answers against your course material.

Frequently asked questions

What is the single best study technique?
The research points to two: active recall and spaced repetition. A 2013 review rated them the only two techniques of high utility out of ten examined. Used together, they are stronger than either alone.

How far apart should my study sessions be?
Space reviews at roughly 10% to 20% of the time until the test — so for an exam in ten days, review after about one to two days.

Do flashcards count as active recall?
Only if you answer before you flip the card. If you read the answer first and then look at the question, you are rereading.

Is cramming ever a good idea?
Cramming can help you pass a test tomorrow, because the material is still fresh. But it is a poor way to remember anything for longer than a few days.

Sources

• 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
• Cepeda, N. J., Pashler, H., Vul, E., Wixted, J. T., & Rohrer, D. (2006). Distributed Practice in Verbal Recall Tasks: A Review and Quantitative Synthesis. Psychological Bulletin, 132(3), 354–380. https://doi.org/10.1037/0033-2909.132.3.354
• Cepeda, N. J., et al. (2008). Spacing Effects in Learning: A Temporal Ridgeline of Optimal Retention. Psychological Science, 19(11), 1095–1102. https://doi.org/10.1111/j.1467-9280.2008.02209.x
• Agarwal, P. K., et al. (2021). Retrieval Practice in the Classroom (review of 50 classroom experiments). Cited via Kuest, “Active Recall and Spaced Repetition: How They Work” — https://www.kuestai.com/blog/active-recall-and-spaced-repetition
• Donoghue, G., & Hattie, J. (2021). Meta-analysis of learning techniques (242 studies, 169,000+ participants). Cited via Recallify, “The Evidence for Spaced Repetition and Active Recall” — https://recallify.ai/evidence-for-active-recall-and-spaced-repetition/
• Larsen, D. P., Butler, A. C., & Roediger, H. L. (2009). Repeated testing and long-term retention in medical residents. Cited via Oncourse, “Active Recall vs Spaced Repetition (2026)” — https://getoncourse.ai/blog/active-recall-vs-spaced-repetition-medical-students-usmle-2026/

All facts and figures above were checked against these sources on 9 November 2026. The Agarwal (2021), Donoghue & Hattie (2021) and Larsen et al. (2009) findings are reported here as cited in the secondary sources listed; the primary papers were not opened directly on 9 November 2026.