Close the book and test yourself before rereading
Rereading creates familiarity without necessarily creating durable memory. Testing yourself with the book closed is more effective. Adding classroom quizzes produces a moderate improvement in achievement, and self-testing ranks among the most useful common learning techniques. After a section, write its main points from memory and then check them.
What it takes
No money or extra total time. Replace rereading with recalling key points in writing or answering questions from memory. Self-testing feels harder because it immediately exposes what you have not retained.
What you may gain
A meta-analysis of 222 independent studies involving 48,478 students found a moderate improvement in achievement from classroom testing, with g=0.499. Effects depended on the comparison group's study method, whether practice and final tests used matching formats and material, corrective feedback, repetitions, where and when tests occurred, intervention duration, and experimental design. A separate review of ten commonly used learning techniques rated practice testing and distributed practice as high utility because both worked across learner ages and abilities and had been supported in multiple assessment formats and real educational settings.
Context & considerations
The purpose is to retrieve information, not assign yourself a grade. Read a section, close the book, write the main points, then compare them with the text. Corrective feedback improves results, so work out why each error occurred. The source rates the benefit “large” from the effect size and utility rating; these studies measured achievement rather than hours saved, so the book's time-saving thresholds were not applied. Combine self-testing with spacing practice across days, the other technique rated highest in the same review.
Research & references
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