How far apart should flashcard practice be? Spacing for elementary kids
Short answer: spread practice over days rather than cramming it into one sitting. Children remember more from three 10-minute sessions on different days than from one 30-minute session. A good rule of thumb is to review again just as something starts to feel slightly hard to recall: the next day, then a few days later, then a week or two after that.
What is the spacing effect?
The spacing effect is the finding that the same amount of practice works better when it is split up over time. Hermann Ebbinghaus described it in the 1880s, and it has been replicated hundreds of times since. A 2006 meta-analysis pooled 839 comparisons from 317 experiments and found spaced practice beat massed practice (Cepeda et al., 2006).
How long should the gap be?
It depends on how long you want the memory to last. In a large study of more than 1,350 people, researchers varied the gap between a first study session and a review, then tested people up to a year later (Cepeda, Vul, Rohrer, Wixted & Pashler, 2008). Two patterns stood out:
- Lengthening the gap helped at first, then slowly hurt. Too short a gap and the review is easy and pointless. Too long and the memory is mostly gone.
- The best gap grew as the test got further away. For a test one week later, the best gap was about 20–40% of that week, so 1 to 3 days. For a test a year later, it was about 5–10% of the year, so roughly 3 to 5 weeks.
| You want them to remember it for… | Review again after about… |
|---|---|
| A spelling test on Friday | 1–2 days |
| The end of the month | 3–7 days |
| The end of the school year | 3–5 weeks, then again later |
A simple schedule for spelling words and math facts
You do not need an app to do this. Three piles of cards work:
- New pile: cards introduced today. Practise them today and again tomorrow.
- Shaky pile: anything missed. Review every one or two days.
- Solid pile: answered correctly twice in a row on different days. Review once a week, then every few weeks.
Move cards down a pile when they are missed and up when they are recalled on a later day. This is a simple version of the Leitner system, and it builds in both retrieval and spacing.
Common mistakes
- Practising until it is perfect, once. Ten correct answers in a row in one sitting mostly measures short-term memory. Come back tomorrow.
- Dropping cards too early. "Got it on Monday" is not "knows it". Keep solid cards in a slow rotation.
- Only reviewing what is new. Mixing in older material is what makes spacing work. It also helps children tell similar ideas apart (×6 versus ×7, their versus there).
- Making sessions long. For ages 6–10, 10–15 focused minutes beats 40 tired ones.
Why it works
Psychologists still debate the exact mechanism. A leading explanation is that a short delay lets the memory fade slightly, so the review takes effort, and effortful retrieval strengthens memory more than easy retrieval does. Sean Kang's 2016 policy review argues spacing should be built into curricula, not left to students. Children almost never space on their own, because cramming feels more productive.
DadSchool's flashcards and per-topic tests let you return to a topic days later and check what has stuck.
References
- 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.
- Cepeda, N. J., Vul, E., Rohrer, D., Wixted, J. T., & Pashler, H. (2008). Spacing effects in learning: A temporal ridgeline of optimal retention. Psychological Science, 19(11), 1095–1102.
- Kang, S. H. K. (2016). Spaced repetition promotes efficient and effective learning. Policy Insights from the Behavioral and Brain Sciences, 3(1), 12–19.