After studying, close the book and test yourself — don’t just reread it.

Rereading a section often makes it seem very familiar, but that doesn’t mean you’ve actually retained it well. Testing yourself after reading yields noticeably better results. In classrooms where brief quizzes are added, average test scores rise by a moderate amount. When ranking ten common study methods, self-testing comes out on top. After finishing a section, try writing down the key points from memory before checking them against the text.

There’s no cost involved, and no extra time is needed. Use the time you’d otherwise spend rereading to write down or answer questions from memory instead. The difficulty lies in how uncomfortable it feels to confront what you’ve forgotten right away, compared to the relative ease of rereading.

A meta-analysis of 222 separate studies involving 48478 students found that classroom quizzes led to a moderate improvement in academic performance (effect size g = 0.499). This effect varies depending on several factors: the baseline study method used in the control group, how closely the quiz format matches the final exam, whether the material is comparable, whether corrective feedback is provided, how many times the quiz is administered, when and where it takes place, how long the intervention lasts, and the experimental design used. Another comprehensive review that evaluated all ten widely used study techniques rated “practice testing” and “spaced practice” as the most effective methods overall. Their high utility stems from proven success across learners of different ages and abilities, as well as in diverse testing formats and real-world educational settings.

Self-testing is meant to force information out of your memory, not to assign grades. The recommended approach is to write down key points from memory after reading a section, then check them against the text. Providing corrective feedback further boosts effectiveness, so it’s important to carefully review why each answer was incorrect. The “large” magnitude of benefit mentioned here is determined by both the effect size and the overall rating. Since these studies measured academic outcomes rather than time saved, they weren’t evaluated against time‑saving thresholds. Self-testing and the method described in item 15 — spreading the same amount of study time across several days — are the two highest‑rated strategies identified in the same review; using them together yields the best results.

Yang C, Luo L, Vadillo MA, Yu R, Shanks DR (2021). Testing (quizzing) boosts classroom learning: A systematic and meta-analytic review. Psychological Bulletin, 147(4), 399–435. https://doi.org/10.1037/bul0000309；Dunlosky J, Rawson KA, Marsh EJ, Nathan MJ, Willingham DT (2013). Improving Students' Learning With Effective Learning Techniques: Promising Directions From Cognitive and Educational Psychology. Psychological Science in the Public Interest, 14(1), 4–58. https://doi.org/10.1177/1529100612453266