Active Recall vs Rereading: Which Works Better for Learning?

What is the difference between active recall and rereading?

Rereading means going over the same text or notes again. Active recall, also called retrieval practice, means producing the information from memory: closing the book and writing down what you remember, answering questions, or working through flashcards before you look at the answers.

Both use the same material. The difference is the direction. Rereading puts the information in front of you again; recall makes you bring it back yourself.

The benefit of recall has a name, the testing effect: taking a memory test does not only show what you know, it also improves how much you keep ^[1]. It has been studied, on and off, since at least 1917 ^[1]. The active recall method page explains how to practise it step by step.

The classic experiment: recall versus rereading

In 2006, Henry Roediger and Jeffrey Karpicke reported two experiments with undergraduates aged 18 to 24 ^[1]. The students read short prose passages of 256 and 275 words, about the sun and about sea otters. Then they either read a passage again or wrote down as much of it as they could remember, with no feedback on what they had missed ^[1].

In the first experiment, with 120 students, the winner depended on when the final test came ^[1]:

The figures are the share of the passage's ideas that students recalled on the final test.

In the second experiment, with 180 students, one group read the passage in four study periods, a second read it in three periods and then recalled it once, and a third read it once and then tried to recall it three times ^[1]. Five minutes later, the group that only read did best (83% against 71% for the repeated-recall group). A week later the order reversed: 61% for the repeated-recall group against 40% for the readers, although the readers had got through the passage 14.2 times on average and the repeated-recall group only 3.4 times ^[1].

These are two experiments with short texts, university students and a written recall test. The next question is whether the pattern holds more widely.

What larger reviews found

A note on numbers: several of these reviews report an effect size called g or d, a standard way of expressing the difference between two groups so that studies with different tests can be combined. Larger numbers mean bigger differences.

Testing versus restudying. A 2014 meta-analysis pooled 159 effect sizes from 61 studies reported between 1975 and 2013, each comparing practice tests with restudying the same material ^[2]. On average testing came out ahead (g = 0.50), although results varied a great deal between studies: 81% of the effects favoured testing and 18% favoured restudying ^[2]. The benefit was larger when the final test came at least a day later (g = 0.69, against 0.41 for shorter delays) and when people were shown the correct answers after the practice test (g = 0.73, against 0.39 without) ^[2].

A second meta-analysis, published in 2017, also found practice tests more beneficial for learning than restudying or any other comparison activity, with the size of the benefit depending on the kind of test, the learners and the design of the study ^[6].

In real classrooms. A 2021 review brought together data from 48,478 students in 222 studies carried out in classrooms ^[3]. Quizzing raised academic achievement by an amount the authors describe as medium (g = 0.499), and the size of the effect depended on factors such as what the comparison group did, whether corrective feedback was given and how many times students were tested ^[3]. Another 2021 review used a narrower definition of classroom research and coded 50 experiments with 5,374 students; 57% of the 49 effect sizes showed medium or large benefits of retrieval practice ^[7].

Not only for memorising facts. In a 2011 study, 80 undergraduates studied a science text and then either built a concept map of it with the text in front of them, a technique that asks learners to draw the links between ideas, or practised recalling it: they wrote down what they remembered, reread the text and recalled it again, in the same total time ^[8]. A week later, on a short-answer test that included questions requiring inferences, the recall group scored 67% against 45% for the concept-mapping group, and concept mapping did not do significantly better than spending extra time reading ^[8]. A meta-analysis of 192 effect sizes from 122 experiments found that what people learn by testing can also carry over to questions they did not practise (d = 0.40 compared with re-exposure to the material), most clearly to application and inference questions ^[9].

In a 2013 review of ten study techniques, practice testing was one of only two rated high utility, and rereading was rated low utility ^[10].

Why rereading feels like it works

If recall works better, why do so many students reread? In a survey of 177 college students, most said they repeatedly read their notes or textbook, and relatively few tested themselves ^[11]. Several findings help explain the habit.

Rereading wins in the short term. Five minutes after studying, rereading gave the better scores in both of the classic experiments ^[1]. That short-term advantage is exactly what you notice while you are studying.

It makes people confident. Students who had read the passage four times were more confident than the recall groups that they would remember it a week later, and after a week they remembered the least ^[1]. In the concept-mapping study, students predicted that repeated reading would give the best long-term retention and recall the worst, the opposite of what happened ^[8].

Ease of reading is a misleading signal. Psychologists call people's estimates of how well they will remember something judgements of learning. A review of how people manage their own learning found that these judgements are swayed by how fluent the material feels at the time, so people often misjudge how well they have learned ^[4]. In one series of experiments, people predicted they would remember words printed in a large font better than words in a small font, although font size had little relationship with what they recalled ^[12]. The illusion persisted even when participants were warned that font size has little effect on memory, and it disappeared when the large words were made harder to read ^[12].

A page you have read three times is easy to read. That feels like knowing it, but it is not a test of whether you can produce it without the page.

When rereading still helps

Rereading is not useless. The research points to a few specific situations.

Reading once to understand. You cannot recall what you never took in. Even the recall-based routine described below starts with a reading ^[13].

An immediate reread adds little. In four experiments in which people read textbook chapters or a Scientific American article, rereading straight away did not, with only a few exceptions, improve their scores on multiple-choice questions, short-answer questions or written summaries; readers' comprehension ability did not change this pattern ^[14].

A delayed reread can help. In two experiments with 423 college students, people read a text once, twice in a row, or twice with a week in between ^[5]. Reading twice in a row helped on a test taken straight away, but not on a test two days later. Reading twice a week apart showed the opposite pattern: no clear gain on the immediate test, but better scores on the delayed one ^[5]. If you do reread, spreading it out is the better bet; the spaced repetition method page shows how to plan reviews over days.

Checking after you recall. Recall works best when you then see what you missed. In the 2014 meta-analysis, studies without feedback in which people recalled 50% or less on the practice test showed no reliable benefit over restudying (g = 0.03), while studies that showed people the correct material after testing produced the largest average benefits ^[2]. Looking back at the text to check your recall is rereading with a purpose.

How to turn reading into recall

The simplest change is to put a recall attempt between reading and rereading. In two experiments with college students, a "read, recite, review" routine (read a passage, recite as much as you can remember without looking, then review the passage) improved free recall of fact-based passages, both straight away and a week later, compared with rereading or taking notes ^[13]. With longer, more complex passages on engineering topics, it beat rereading on multiple-choice and problem-solving questions, and matched note-taking while taking less study time ^[13].

Some ways to build recall into reading:

• The blank page. After a section, close the book and write down everything you remember, then check it against the text.
• Headings as questions. Turn each heading into a question ("What causes…?", "How does…?") and answer it before you read the section again.
• Recall, not recognition. Practice tests that asked people to produce the answer gave larger benefits than tests that asked them to pick it out, although recognition tests still helped ^[2].
• Come back on another day. The benefit of testing was larger when the final test was at least a day after practice ^[2], which is how most exams work. For why the timing of reviews matters, see The spacing effect.

On LaserMind, Recall Cards are flashcards you write yourself: you see the question, answer it in your head, then show the answer and rate how well you recalled it, and the scheduler decides when the card comes back. Explain It Simply asks you to explain a topic in plain words and note where you got stuck, then turns up to eight of your own questions and answers into a Recall Cards deck. For a complete weekly study plan that combines recall with spacing and other techniques, see How to improve memory for studying.

Why might recall work better?

The authors of the classic experiments discussed a few explanations, which are theories rather than settled facts. One is that recalling during study practises the very skill a later test demands; another is that testing adds a "desirable difficulty", a condition that makes learning harder at the time but helps long-term retention ^[1]. The 2014 meta-analysis found support for the role of effortful retrieval, since recall tests gave larger benefits than recognition tests, and only limited support for the idea that testing works by making people elaborate on meaning ^[2]. The authors of the concept-mapping study concluded that retrieval helps through its own mechanisms rather than as a form of elaborative study ^[8].

What the research says

Frequently asked questions

Is rereading a waste of time? Not entirely. You need to read material once to understand it, and looking back at the text after a recall attempt shows you what you missed. A second reading also helped on a delayed test when it came a week after the first ^[5]. What adds little is rereading straight away as your main way of studying ^[14].

Is a multiple-choice quiz as good as recalling from memory? Both help, but practice tests that asked people to produce the answer gave larger benefits than tests that asked them to recognise it ^[2].

What if I can barely remember anything when I test myself? Check the material straight away, then try again later. Without feedback, practice tests on which people recalled half or less gave no reliable advantage over restudying, while testing followed by the correct answers gave the largest benefits ^[2].

References

1. 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
2. Rowland, C. A. (2014). The effect of testing versus restudy on retention: A meta-analytic review of the testing effect. Psychological Bulletin, 140(6), 1432–1463. https://doi.org/10.1037/a0037559
3. Yang, C., Luo, L., Vadillo, M. A., Yu, R., & Shanks, D. R. (2021). Testing (quizzing) boosts classroom learning: A systematic and meta-analytic review. Psychological Bulletin, 147(4), 399–435. https://doi.org/10.1037/bul0000309
4. Bjork, R. A., Dunlosky, J., & Kornell, N. (2013). Self-regulated learning: Beliefs, techniques, and illusions. Annual Review of Psychology, 64(1), 417–444. https://doi.org/10.1146/annurev-psych-113011-143823
5. Rawson, K. A., & Kintsch, W. (2005). Rereading Effects Depend on Time of Test. Journal of Educational Psychology, 97(1), 70–80. https://doi.org/10.1037/0022-0663.97.1.70
6. Adesope, O. O., Trevisan, D. A., & Sundararajan, N. (2017). Rethinking the use of tests: A meta-analysis of practice testing. Review of Educational Research, 87(3), 659–701. https://doi.org/10.3102/0034654316689306correction
7. Agarwal, P. K., Nunes, L. D., & Blunt, J. R. (2021). Retrieval Practice Consistently Benefits Student Learning: a Systematic Review of Applied Research in Schools and Classrooms. Educational Psychology Review, 33(4), 1409–1453. https://doi.org/10.1007/s10648-021-09595-9
8. Karpicke, J. D., & Blunt, J. R. (2011). Retrieval Practice Produces More Learning than Elaborative Studying with Concept Mapping. Science, 331(6018), 772–775. https://doi.org/10.1126/science.1199327
9. Pan, S. C., & Rickard, T. C. (2018). Transfer of test-enhanced learning: Meta-analytic review and synthesis. Psychological Bulletin, 144(7), 710–756. https://doi.org/10.1037/bul0000151
10. 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
11. Karpicke, J. D., Butler, A. C., & Roediger III, H. L. (2009). Metacognitive strategies in student learning: Do students practise retrieval when they study on their own? Memory, 17(4), 471–479. https://doi.org/10.1080/09658210802647009
12. Rhodes, M. G., & Castel, A. D. (2008). Memory predictions are influenced by perceptual information: Evidence for metacognitive illusions. Journal of Experimental Psychology: General, 137(4), 615–625. https://doi.org/10.1037/a0013684
13. McDaniel, M. A., Howard, D. C., & Einstein, G. O. (2009). The Read-Recite-Review Study Strategy: Effective and Portable. Psychological Science, 20(4), 516–522. https://doi.org/10.1111/j.1467-9280.2009.02325.x
14. Callender, A. A., & McDaniel, M. A. (2009). The limited benefits of rereading educational texts. Contemporary Educational Psychology, 34(1), 30–41. https://doi.org/10.1016/j.cedpsych.2008.07.001
15. van Gog, T., & Sweller, J. (2015). Not New, but Nearly Forgotten: the Testing Effect Decreases or even Disappears as the Complexity of Learning Materials Increases. Educational Psychology Review, 27(2), 247–264. https://doi.org/10.1007/s10648-015-9310-x
16. Karpicke, J. D., & Aue, W. R. (2015). The Testing Effect Is Alive and Well with Complex Materials. Educational Psychology Review, 27(2), 317–326. https://doi.org/10.1007/s10648-015-9309-3