Active recall: the evidence for retrieval practice and how to use it

What active recall is

Active recall means pulling information out of your memory instead of putting it back in. You close the book and try to answer a question, explain a concept from memory or work a problem without looking at the solution. Researchers call the same thing retrieval practice, and the benefit it produces is known as the testing effect.

The opposite is passive review: rereading notes, rewatching videos, scanning highlighted text. Passive review feels productive because the material looks familiar. Active recall feels harder because you notice what you cannot remember. That difficulty is the point.

In a review in Trends in Cognitive Sciences, Roediger & Butler, 2011 concluded that retrieval practice often produces large gains in long-term retention compared with repeated studying. It works even without feedback, works better with feedback, and helps people apply knowledge flexibly in new situations, not only repeat it word for word.

The key experiments on retrieval practice

Testing beats restudying, but only after a delay

In Roediger & Karpicke, 2006, students read short prose passages. Some then took one or three free-recall tests without feedback; others restudied the passage the same number of times. A final test came 5 minutes, 2 days or 1 week later.

At 5 minutes, restudying won. On the delayed tests, the students who had been tested remembered substantially more. Repeated studying also made students more confident about how much they would remember. This is the trap: the method that wins on the same day is not the method that wins on exam day.

Recalling once is not enough

Karpicke & Roediger, 2008 taught students foreign-language vocabulary. Once a student had produced a word correctly, it was either dropped from further study, dropped from further testing, or both. Repeated studying after that point had no effect on delayed recall. Repeated testing produced a large positive effect. Students' own predictions of how well they would do were uncorrelated with how they actually did.

The practical lesson: getting an answer right once does not mean you are done. Keep retrieving it on later days.

It holds up in real classrooms

Lab studies use short, controlled materials, so it is fair to ask whether the effect survives a real course. A meta-analysis of 72 effect sizes from psychology classes found an overall advantage of d = 0.56 for testing (Schwieren et al., 2017). An effect size of d = 0.56 means the average tested student scored a bit over half a standard deviation above the average student who did not practise retrieval; by the usual rule of thumb that is a moderate effect. A broader meta-analysis by Adesope et al., 2017 found practice tests more beneficial than restudying and every other comparison condition, with the size of the benefit depending on test features and study design.

Why most students still reread

When Karpicke et al., 2009 surveyed 177 college students about how they study, most said they repeatedly reread their notes or textbook, and relatively few tested themselves. The authors suggest students fall for "illusions of competence": material that is easy to read feels like material that is well learned. A major review of ten study techniques rated rereading and highlighting as low utility and practice testing as high utility (Dunlosky et al., 2013).

A 2024 study of 186 psychology students shows the illusion directly. In the rereading group, students' judgements of how well they had learned rose after each reading, and they were overconfident, especially when tested a day later (Seban et al., 2024).

There is a fair counterpoint. In three preregistered experiments with 306 participants, Weissgerber & Rummer, 2022 found that when learners imagined a test one to two weeks away, their judgements often favoured testing over rereading. Learners may understand the value of testing better than older research suggested. Knowing it and doing it are still different things, which is why a fixed protocol helps.

Does the type of question matter?

Yes. A meta-analysis of the testing effect found that initial recall tests produced larger benefits than recognition tests (Rowland, 2014). Recall means producing the answer yourself; recognition means picking it from options, as in multiple choice. The more effort retrieval takes, the more it seems to strengthen memory.

Certification exams are mostly multiple choice, so you need both kinds of practice:

• Recall first. Before you look at the options, cover them and try to answer the question in your own words. Then check the options.
• Explain the distractors. For each wrong option, say why it is wrong. This turns a recognition question back into a recall task.
• Read the explanation every time. Roediger & Butler, 2011 note that feedback enhances the benefit of retrieval. Our free practice tests show an explanation for every answer for exactly this reason.

Active recall techniques that work

Any method that makes you produce an answer from memory counts. These are the most practical for exam preparation:

• Practice questions. The closest match to the real exam. Use them from week one, not only at the end. See the testing effect for how many to take.
• Flashcards, used honestly. Say or write the answer before you flip the card. A box system such as the Leitner system decides which cards come back and when.
• The blank page. After a study session, write down everything you remember about the topic on an empty page, then compare with your notes and fill the gaps in a different colour.
• Questions in the margin. Turn each heading of your notes into a question. Review by answering the questions with the notes covered.
• Explain it out loud. Teaching a concept to an imaginary beginner, as in the Feynman technique, is retrieval plus explanation.

Active recall works best when it is spread out over days. One session of self-testing helps; the same number of tests spaced across a week helps more. That is the subject of spaced repetition, and the two methods are strongest together.

Limits and honest caveats

• Most evidence is about facts and concepts. Donoghue & Hattie, 2021 found practice testing among the two most effective of ten techniques (d = 0.74 in their analysis), but most studies in their meta-analysis measured surface or factual outcomes. Evidence for deep, relational understanding is thinner.
• The same-day result can mislead you. As Roediger & Karpicke, 2006 showed, restudying can look better on an immediate test. Judge your method by what you remember days later.
• Feedback matters for wrong answers. Retrieval without checking can let a wrong answer feel familiar. Always check.
• It feels slower. Retrieval is a desirable difficulty: effortful in the moment, better later. Expect it to feel worse than rereading.

How to use this for a certification exam

This protocol assumes a multiple-choice certification exam such as CompTIA Security+ and about six weeks of study. Adjust the numbers to your timeline.

1. Day 1: baseline. Take our free Security+ practice test (or the test for your exam) cold. Note your score per domain. Do not study first.
2. Every study session: 25 minutes in, 10 minutes out. After each block of reading or video, close it and write everything you remember on a blank page. Then check and correct.
3. Write 10 questions per session. Turn each new objective into a question you could be asked. Answer yesterday's 10 questions before you start today's material.
4. Recall before options. On every practice question, cover the answer choices, answer in your own words, then choose. For each wrong option, write one line on why it is wrong.
5. Drop nothing after one correct answer. A question you got right goes back into the pool for 3 days later and again 7 days later. A question you got wrong comes back the next day.
6. Weekly mixed set. Once a week, answer 30 to 40 questions drawn from all domains, timed. Retake our free practice test every two weeks and compare domain scores with your baseline.
7. Final week. No new material. Only retrieval: mixed question sets, blank-page reviews of weak domains, and the explanations of every question you missed.

Studying for a different exam? The same steps work with our PMP practice test or any of the others. For the full picture of which techniques to combine, read how to study effectively.