Retrieval Practice (Active Recall): How the Testing Effect Works and What the Research Shows

By the IQ Revealed Team · Updated October 26, 2026

Retrieval practice, also called active recall, is learning by bringing information back to mind: after studying, you close the book and try to recall it, by answering questions, using flashcards or writing down what you remember. Recalling something strengthens the memory more than reading it again, a result psychologists call the testing effect. It is one of the most reliable findings in learning research, and it works against intuition: rereading feels more productive, but a week later the students who tested themselves remember more.

Retrieval practice at a glance

What it is: recalling material from memory instead of reviewing it on the page.
Other names: active recall, the testing effect, practice testing, test-enhanced learning.
What it beats: rereading, highlighting and, in one well-known study, making concept maps.
The catch: it feels harder and less productive than rereading, so learners tend to underrate it.
Best combined with: feedback (check your answers) and spaced repetition (recall again after days, not minutes).
Not a route to a higher IQ: it improves what you remember, not general reasoning.

The experiment that revived it

The idea is old. Early studies of recitation, such as Arthur Gates’s work in 1917, already found consistent benefits from recalling material instead of only reading it. But the finding sat largely unused in classrooms until 2006, when Henry Roediger and Jeffrey Karpicke at Washington University in St. Louis tested it with the kind of material students actually study.

Students read short prose passages. Some then reread them; others took a recall test, writing down everything they could remember, with no feedback. A final test came five minutes, two days or one week later. The result is the whole case for active recall in one experiment:

After five minutes, rereading won. The material was still fresh, and the students who had read it twice did better.
After two days and after a week, testing won, and by a wide margin. Recalling the passage once had protected it from forgetting far better than reading it again.
Rereading raised confidence. The students who restudied predicted they would remember more, even though they later remembered less.

That pattern explains why so many people study the wrong way. Every immediate signal, how fluent the page feels and how well you do on a quiz five minutes later, rewards rereading. The benefit of recall only shows up after the forgetting that our article on the forgetting curve describes has had time to happen.

What the wider evidence shows

It holds across hundreds of studies

The 2013 review of ten common study techniques by John Dunlosky and colleagues rated practice testing one of only two techniques of high utility; the other was spreading study out over time. Rereading, highlighting and summarising were rated low. A 2017 meta-analysis by Olusola Adesope and colleagues pooled 217 studies and found that practice tests were more beneficial for learning than restudying and than every other comparison condition they examined. Christopher Rowland’s 2014 meta-analysis found that the benefit was larger when the practice test asked people to recall the answer than when it only asked them to recognise it, which is why a blank page beats a multiple-choice quiz.

It works in real classrooms, not only in labs

In a 2021 systematic review, Pooja Agarwal, Ludmila Nunes and Janell Blunt kept only studies run in real schools and courses with real course material: 50 experiments, 5,374 students. The majority of the effects, 57%, were medium or large, across age groups from primary school to medical school and across subjects. In one of the classroom studies, sixth-grade social studies students who took short low-stakes quizzes did better on their actual chapter and end-of-semester exams. The review also noted a limit: only 6% of the experiments were run outside the United States and Western Europe.

It is not only for memorising facts

A common objection is that testing yourself only builds rote memory. Karpicke and Janell Blunt (2011) compared retrieval practice with making concept maps, a technique designed to build understanding. Retrieval practice produced more learning, including on questions that required inferences, and it did so even when the final test was itself a concept map. At Copenhagen University Hospital, Charles Kromann and colleagues (2009) found a testing effect for a practical skill: medical students whose resuscitation course ended with 30 minutes of testing instead of 30 more minutes of practice scored 82.8% against 73.3% in a simulated emergency two weeks later.

It also helps the next thing you learn

Bernhard Pastötter and Karl-Heinz Bäuml at the University of Regensburg reviewed a less famous result: recalling one block of material can improve learning of the next block, not only memory for the one you tested. Researchers call this the forward effect of testing, and it is one reason short quizzes between sections of a lecture or a chapter are worth the time.

How to use active recall

Close the source first. The work happens only when the answer is not in front of you. Looking at the answer while you “test” yourself turns recall back into rereading.
Prefer producing to recognising. Write the answer, say it aloud or sketch the diagram from memory. Recall gives a bigger benefit than picking from options.
Check, then correct. Compare what you produced with the source and fix the gaps. Feedback makes sure you do not practise mistakes.
Recall again later. One test helps; repeated, spaced tests help more. Our guide to spaced repetition covers how long the gaps should be.
Keep the stakes low. The benefit comes from recalling, not from the grade. Ungraded quizzes and self-tests work.

Five ways to do it

Blurting (the brain dump): write everything you remember about a topic on a blank page, then check your notes and add what you missed in a different colour. It is free recall, the same task used in the 2006 experiment.
Flashcards: answer before you turn the card, out loud or in writing, not just in your head as a vague “I know this”.
Practice questions: past papers, end-of-chapter questions or questions you write for yourself while studying.
Explain it to someone: teach the idea from memory to a friend, or to an empty room.
Turn headings into questions: cover a page, read only its heading and recall what the section said.

Why recalling strengthens memory

No single explanation has won, but several fit the evidence. Recalling takes effort, and effortful retrieval seems to strengthen the memory and the cues that lead back to it; psychologists call useful effort of this kind a desirable difficulty. Rowland’s meta-analysis found stronger support for this effort-based account than for the idea that testing works simply by making people think more about meaning. Mihály Racsmány and colleagues in Budapest (2018) added another angle: across practice tests, people recall faster and faster, in the same curve that marks a skill becoming automatic, and the more closely recall followed that curve, the better it held up later. On this view, retrieval practice turns remembering into a practised skill. Testing also does something rereading cannot: it shows you which parts you do not know, a skill our article on metacognition covers.

Retrieval practice and IQ

Retrieval practice will not raise your IQ. It improves memory for what you study, which can raise exam results and scores on tests of acquired knowledge, but there is no evidence that it improves general reasoning on new problems. That distinction, between what you know and how well you reason with new material, is the one our article on fluid vs crystallized intelligence draws, and claims that a study method makes you more intelligent run into the transfer problem described in our guide on how to increase IQ. It pairs naturally with mnemonic devices for hard-to-hold lists: build the mnemonic, then recall it on a spaced schedule.

Trust and scope notes

This page summarises published research for general information. The figures quoted are those reported by the studies listed below; where a study’s exact numbers are not quoted, the page describes its direction of effect as its authors did. It is not medical or educational advice: memory problems that are new, worsening or worrying deserve a conversation with a doctor, and no online test can assess them. The IQ Revealed test is an online reasoning test of 40 original items for adults aged 18 and over; it is not a clinical assessment and it does not measure memory. Our guide to how IQ tests work explains what an online test can and cannot tell you.

IQ Revealed is not affiliated with, endorsed by or connected to the researchers, universities, hospitals, journals or publishers named on this page, or any flashcard app or study website. Names are used only to identify the research being described.

Frequently asked questions

What is retrieval practice?＋

Retrieval practice is learning by recalling: after you study something, you close the book and try to bring it back from memory, by answering questions, using flashcards, writing down everything you remember or explaining it aloud. The act of recalling strengthens the memory more than reading the material again. Researchers call the result the testing effect.

Is active recall the same as retrieval practice?＋

Yes, in practice. "Active recall" is the name students and study channels use; "retrieval practice" and "the testing effect" are the names in the research literature. All three describe the same thing: pulling information out of memory instead of putting it in again by rereading.

Does retrieval practice really work?＋

Yes. It is one of the best-supported findings in learning research. A 2013 review of ten study techniques rated practice testing as one of only two of high utility, and a 2017 meta-analysis of 217 studies found practice tests beat restudying and every other comparison condition. A 2021 review of 50 classroom experiments with 5,374 students found that 57% of the effects were medium or large.

What is the blurting method?＋

Blurting is a study technique in which you write down everything you can remember about a topic on a blank page, then check your notes and fill the gaps in another colour. It is a form of free recall, the same task students did in the 2006 experiment that revived research on the testing effect. Its strength is that it shows you exactly what you have not yet learned.

Why does rereading feel better than testing yourself?＋

Because rereading makes the material feel familiar, and familiarity is easy to mistake for knowing. In the 2006 experiment, students who reread a passage were more confident about remembering it, yet a week later they recalled less than students who had tested themselves. Testing feels harder because recall is effortful, and that effort is part of why it works.

What is the difference between retrieval practice and spaced practice?＋

Retrieval practice is about how you review: by recalling instead of rereading. Spaced practice is about when you review: in sessions spread over days or weeks instead of all at once. They are separate techniques that combine well, and spaced retrieval practice, short self-tests on a spread-out schedule, is the combination the research supports most strongly.

Does retrieval practice increase IQ?＋

No. Retrieval practice makes what you study stick, which can raise exam results and scores on tests of knowledge, but there is no evidence that it raises general reasoning ability, the thing IQ tests are designed to measure.