Active recall and spaced repetition: what to do at each pass
Published · Updated
Sources checked on by Alexandre Doumergue, founder of Paced.
Two ideas, one plan
- Spaced repetition is a schedule: review on growing gaps instead of all at once (which gaps, and why).
- Active recall is a way of reviewing: retrieve from memory before looking, instead of rereading.
“Spaced repetition vs active recall” is a false choice. Rereading on a perfect schedule wastes the schedule; recalling everything in one evening wastes the recall. The studies below tested each one on its own; a plan simply applies both, since they answer different questions.
What the research says
- Practising recall of a text beat restudying it on tests two days and one week later, even though restudying felt more effective at the time (Roediger & Karpicke, 2006).
- In a study of foreign-language word pairs, repeated retrieval was what produced long-term retention; repeated study after an item had been recalled added little (Karpicke & Roediger, 2008).
- A meta-analysis of the testing effect found larger benefits for tests that require recall than for tests of recognition (Rowland, 2014).
- A review of ten study techniques rated practice testing and distributed practice as high utility, rereading and highlighting as low (Dunlosky et al., 2013).
- Feedback after a wrong answer raised later recall a great deal; after a correct one it added little (Pashler et al., 2005). Checking is where you fix errors: do not skip it.
The active recall study method, pass by pass
Two topics, one first studied for 1 h and one for 2 h 30, on Paced's Standard pace. The lengths are Paced's default review curve (30% of the first study for the first review, 4 points less for each next one, never under 10% nor 5 minutes) — planning defaults, not values from a study:
| Pass | 1 h topic | 2 h 30 topic | What to do |
|---|---|---|---|
| D0 | 1 h | 2 h 30 | Learn the topic. Stop 10 minutes early and write, notes closed, everything you can recall. |
| D+1 | 18 min | 45 min | Blank-page recall of the whole topic, then check against the notes. Write 5 to 10 questions on what you missed. |
| D+3 | 16 min | 39 min | Answer yesterday's questions without notes. Then a handful of practice questions. |
| D+7 | 13 min | 33 min | Practice or past-paper questions on the topic, timed. Explain aloud the step you hesitated on. |
| D+15 | 11 min | 27 min | A mixed set: questions from this topic and one or two others, without knowing which is which. |
| D+30 | 8 min | 21 min | A one-page outline from memory, then three questions. |
| D+60, D+120, D+240 | 6 min each | 15 min each | A quick check: outline from memory and two questions. If you cannot start, the topic needs a new first study. |
For a topic first studied for 2 hours, the same pace gives 36 min, 31 min, 26 min, 22 min, 17 min, 12 min. The pattern matters more than the exact minutes: the first reviews rebuild, the later ones only check. The dates for your own start are in the spaced repetition calculator.
Active recall techniques, from lightest to heaviest
Blank-page recall (blurting)
Close everything, take a blank page, and write all you remember about the topic for a fixed time — headings, terms, diagrams, steps. Then open the notes and mark, in another colour, what was missing or wrong. It needs no preparation, which makes it the default for the first reviews.
Your own questions
Turn what you missed into short questions. Answering them at the next pass is targeted recall: you practise exactly what you got wrong.
Practice and past-paper questions
The closest thing to the exam. Use them once the topic is in place (from D+7), and mix topics later on, so that you practise choosing the method as well as applying it. For problem-solving subjects, see spaced repetition for coding interviews: each review is a new problem of the same pattern.
Explaining aloud
Explain the topic as if to a classmate, without notes. Every hesitation marks a gap. Good for the middle passes and for topics with a chain of reasoning.
When a review goes badly
A bad review is information, not failure. If you remember less than half, do not stretch the review to an hour: note the gaps, keep the next review on its date, and if the next one goes badly too, schedule a second first study of the topic. If every review is easy, the gaps can grow faster: switch the topic to a lighter pace. Fitting all of this into a real week is what the study schedule maker does.
Paced plans every first study and review of every topic on its day, with the planned length of each pass, inside the hours you actually have. The web plan is free for up to 8 active topics, 7 days ahead, with no card; the iPhone and iPad app needs Plus. Try it without an account.
Questions
How to do spaced repetition and active recall?
Use spaced repetition for the dates and active recall for the method: at every review, recall with your notes closed first, then check and fix the gaps.
Is active recall better than spaced repetition?
They answer different questions: active recall is how you review, spaced repetition is when. Each was tested separately, and each helped: recall over rereading (Roediger & Karpicke, 2006), spacing over massing (Cepeda et al., 2006). They apply to different questions, so a plan can use both.
How long should an active recall session be?
Shorter than the first study, and shorter as the gaps grow. In our example: 45 min the day after a 2 h 30 study, 15 min from D+60 on.
Can I do active recall without flashcards?
Yes: blank-page recall, your own questions, practice questions and explaining aloud are all active recall. Cards suit isolated facts; whole topics need the other forms.
Sources
- Roediger, H. L., & Karpicke, J. D. (2006). Test-enhanced learning: Taking memory tests improves long-term retention. Psychological Science, 17(3), 249–255. On tests two days and one week later, practising recall beat restudying the same text.
- Karpicke, J. D., & Roediger, H. L. (2008). The critical importance of retrieval for learning. Science, 319(5865), 966–968. Repeated testing had a large effect on delayed recall; repeated studying after learning had none.
- 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. Meta-analysis of the testing effect: recall tests gave larger benefits than recognition tests, which supports effortful retrieval.
- Dunlosky, J., Rawson, K. A., Marsh, E. J., Nathan, M. J., & Willingham, D. T. (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. Review of 10 techniques: practice testing and distributed practice rated high utility; rereading and highlighting low.
- Pashler, H., Cepeda, N. J., Wixted, J. T., & Rohrer, D. (2005). When does feedback facilitate learning of words?. Journal of Experimental Psychology: Learning, Memory, and Cognition, 31(1), 3–8. Feedback after an error raised later recall substantially; after a correct answer it added little.
- Cepeda, N. J., Pashler, H., Vul, E., Wixted, J. T., & Rohrer, D. (2006). Distributed practice in verbal recall tasks: A review and quantitative synthesis. Psychological Bulletin, 132(3), 354–380. Meta-analysis of 839 assessments in 317 experiments: the gap that maximises retention grows with how long you need to remember.