Retrieval practice in Computing: what the research says
Most students revise by re-reading notes and highlighting. It feels productive, but it's one of the least effective ways to remember anything. Pulling information out of memory, by answering questions, does far more. Here's what the research says, and how to use it in Computer Science and IT lessons without adding to your marking.
What retrieval practice is
Retrieval practice means recalling something you've learnt without looking at it: answering a quiz question, filling in a blank, writing down everything you remember about the fetch-decode-execute cycle. The act of recalling strengthens the memory and makes it easier to recall next time. It's often called the testing effect, but the point isn't the test. It's the remembering.
What the research says
In a well-known experiment, Roediger and Karpicke (2006) had students read short passages. Some then reread them; others took a recall test with no feedback. Five minutes later the rereaders did slightly better. A week later the picture had flipped: the students who had tested themselves remembered considerably more.
That pattern, where re-reading feels better at the time but retrieval wins over days and weeks, comes up again and again. A large review by Dunlosky and colleagues (2013) rated ten common study techniques. Only two were rated high utility: practice testing and distributed (spaced) practice. Highlighting and rereading were rated low utility.
Spacing matters as much as quizzing. A meta-analysis by Cepeda and colleagues (2006) found that spreading practice out over time leads to better long-term retention than the same amount of practice done in one go. A practical way to use this in class is to come back to a topic after a day, then a few days, then a week. Each gap gives students the chance to "forget a little" before they retrieve it again, and the extra effort of remembering is part of what makes retrieval work.
It's worth being honest about the limits. The Education Endowment Foundation's review of cognitive science in the classroom (2021) found the evidence for retrieval practice and spacing promising, but noted that results in real classrooms vary more than in the lab, and that how well it's done matters. Low-stakes, frequent and well-chosen questions work best; a weekly high-pressure test is not the same thing.
Why it suits Computer Science so well
- Lots of precise vocabulary. Register, cache, protocol, normalisation, abstraction: students lose marks for nearly-right terms. Short recall questions fix the exact word.
- Facts that underpin problem solving. You can't trace an algorithm or convert binary to hexadecimal fluently if you're still working out the basics. Automatic recall frees up thinking for the harder part.
- Long courses with early content. Systems architecture and memory are taught early in GCSE and examined at the very end. Without spaced retrieval, students effectively relearn them in May.
Five ways to use it in lessons
1. Start with a short quiz on old content
Three to five questions as students arrive: one from last lesson, one from last week, one from last term. Rosenshine's Principles of Instruction (2012) begins with exactly this kind of daily review. See our guide to running a Do Now.
2. Ask for recall, not just recognition
Multiple choice is quick to mark, but recognising the right answer is easier than producing it. Mix in fill-in-the-blank and "write down two reasons…" questions so students have to generate the answer.
3. Give feedback straight away
Retrieval works better with feedback. Students should find out quickly what they got wrong and see the right answer, especially when they were confident and wrong.
4. Bring mistakes back
The questions a student got wrong are the most valuable ones to revisit, a day or two later and again a week later. A simple "mistakes list" in the back of an exercise book works; so does software that schedules it for them.
5. Keep it low stakes
Don't record every quiz score or rank students. The aim is practice, and students take more risks (and learn more) when a wrong answer costs nothing.
Turning it into homework
Homework is the ideal place for spaced retrieval, because it happens between lessons. Short, regular quizzes on a mix of recent and older topics beat one long piece of written homework at the end of a unit. The free revision quizzes on RADevo are a quick way to try this with any GCSE, A Level, Cambridge Nationals, BTEC or KS3 course.
How RADevo builds this in
We built RADevo around these ideas. Every quiz has four activities (fill in the blanks, matching, multiple choice and true or false), so students recall as well as recognise. Every question a student gets wrong comes back in Revise today one day later, then three days, then seven, until they've got it right three times. Teachers see which questions their class found hardest, and a Do Now can be built from those questions in a couple of clicks.
References
- Cepeda, N. J., Pashler, H., Vul, E., Wixted, J. T. and Rohrer, D. (2006). Distributed practice in verbal recall tasks: a review and quantitative synthesis. Psychological Bulletin, 132(3), 354–380.
- Dunlosky, J., Rawson, K. A., Marsh, E. J., Nathan, M. J. and Willingham, D. T. (2013). Improving students' learning with effective learning techniques. Psychological Science in the Public Interest, 14(1), 4–58.
- Education Endowment Foundation (2021). Cognitive science approaches in the classroom: a review of the evidence.
- Roediger, H. L. and Karpicke, J. D. (2006). Test-enhanced learning: taking memory tests improves long-term retention. Psychological Science, 17(3), 249–255.
- Rosenshine, B. (2012). Principles of Instruction: research-based strategies that all teachers should know. American Educator, 36(1), 12–19, 39.