Retrieval practice and spaced practice

If you only change two things about how you study, make it these two. A landmark review of learning research rated testing yourself and spreading your study over time as the most useful techniques it examined.

What the evidence says

• Dunlosky and colleagues (2013) reviewed ten techniques. Only two received a high utility rating: practice testing and distributed (spaced) practice.
• The Association for Psychological Science summarised it simply: by replacing rereading with delayed retrieval practice, students would benefit.
• The Learning Scientists, a group of cognitive psychologists, list retrieval practice and spaced practice among their six strategies for effective learning.
• The Education Endowment Foundation's 2021 review found that cognitive science approaches can make a meaningful difference, but noted that evidence on applying them in real classrooms is still limited. Use them, but stay realistic.

Retrieval practice: pull it out, do not put it in again

• Retrieval practice means bringing information to mind from memory, without looking. Practice quizzes, flashcards (answering before you flip) and past-paper questions all count.
• The simplest version is a 'brain dump': take a blank page and write everything you can remember about a topic. RetrievalPractice.org notes that this can take five minutes or less.
• Make the prompt specific, for example: 'Write the three stages of mitosis and one fact about each' rather than 'biology'.
• After recalling, check your notes to fill gaps and correct mistakes. The Learning Scientists point out you do not need to recall everything; the checking step is part of learning.
• Keep it low stakes. A self-quiz is a learning tool, not a grade, so getting things wrong is useful information, not failure.
• Copying notes out neatly or rereading them is not retrieval. If you can see the answer, you are not retrieving.

Spaced practice: little and often beats cramming

• Spaced practice means spreading study for a topic across several short sessions over days and weeks, rather than one long session.
• The Learning Scientists advise blocking off the time in a schedule and sticking to it, because people tend to put study off when no exam is near.
• Revisit older topics as you learn new ones, so each idea comes back after a gap.
• Example plan for one chemistry topic: learn it on Monday, brain dump on Wednesday, flashcards on Saturday, a mixed past-paper question the following Saturday, then again two to three weeks later.
• Each review should be retrieval first (test yourself), then check. Spacing plus retrieval is more powerful than either alone.

Building a simple system

• Turn each lesson's notes into 5 to 10 questions on the same day. These become your quiz bank.
• Use three piles or boxes for flashcards: 'got it', 'shaky', 'did not know'. Review 'did not know' most often, 'got it' least often.
• Digital flashcard apps with built-in spacing can do the scheduling for you; paper cards work just as well if you follow the piles.
• At the start of each study session, spend 5 minutes recalling last session's topic before starting anything new.
• Study with a friend by quizzing each other. Each person must answer from memory before the other reveals the answer.

Why it feels harder (and why that is good)

• Retrieval and spacing feel slower and more effortful than rereading. You will notice your mistakes more.
• The Learning Scientists stress that this difficulty is useful: the effort of recalling is what strengthens memory.
• Rereading creates a feeling of fluency that can trick you into thinking you know material you cannot actually recall.
• Judge your preparation by what you can produce on a blank page, not by how familiar your notes look.