Spaced repetition is the practice of reviewing material at increasing intervals. It is the most efficient way to move knowledge from short-term to long-term memory.
The forgetting curve
Without review, you forget approximately:
- 50% within 24 hours
- 70% within a week
- 90% within a month
A single review within 24 hours dramatically slows forgetting. A second review after 3 days, a third after a week, and a fourth after a month can maintain retention above 90%.
How to apply spaced repetition to IGCSE Physics
The schedule
After learning a new topic in class or tuition:
| Review | When | Duration | What to do |
|---|---|---|---|
| Review 1 | Same day (evening) | 15 min | Brain dump + check notes |
| Review 2 | 3 days later | 15 min | Self-test with questions |
| Review 3 | 1 week later | 10 min | Flashcard review |
| Review 4 | 1 month later | 10 min | Past paper question on this topic |
| Review 5 | Before the exam | 5 min | Quick definition and equation check |
Practical implementation
The challenge is tracking when each topic is due for review. Options:
Option 1: Calendar method. After each class, write the review dates in your calendar or planner. This is simple and works if you check your calendar daily.
Option 2: Flashcard boxes (Leitner system). Physical flashcards sorted into boxes reviewed at different intervals (see the flashcard guide).
Option 3: Revision tracker spreadsheet. Create a simple spreadsheet with topics as rows and review dates as columns. Tick each cell when the review is done.
What spaced repetition looks like across a year
Term 1 (Topics 1 and 2 being taught)
- Review Topics 1 and 2 at the schedule above.
- Total review time per week: about 30 to 45 minutes.
Term 2 (Topics 3 and 4 being taught)
- Continue reviewing Topics 1 and 2 at monthly intervals.
- Review Topics 3 and 4 at the full schedule.
- Total review time per week: about 45 to 60 minutes.
Term 3 (Topics 5 and 6 being taught, revision starting)
- Monthly reviews of Topics 1 to 4.
- Full schedule for Topics 5 and 6.
- Past paper practice begins (which naturally reviews all topics).
- Total review time per week: about 60 to 90 minutes.
Why students resist spaced repetition
“I do not have time.” You do. Review 1 takes 15 minutes. The total weekly time is less than an hour. Compare this to cramming for 6 hours the night before a test, which produces worse results.
“I will revise everything before the exam.” By then, you have forgotten 90% of what you learned in Term 1. Spaced repetition means you arrive at the exam revision period with most of the content already in long-term memory. Your revision time can then focus on practice and technique instead of relearning.
“It feels like I am doing unnecessary work.” Each review is short and targeted. It feels unnecessary because you still remember the content, and that is exactly the point: you review BEFORE you forget, not after.
Combining spaced repetition with other methods
Spaced repetition works best when combined with active recall. Do not re-read your notes during reviews. Instead:
- Try to recall before checking.
- Test yourself with questions.
- Explain the concept without notes.
The combination of active recall and spaced repetition is the most powerful study method supported by research.
Apply this study skill next
Need a Plan Based on Actual Work?
A private taught trial can help distinguish whether the repeated difficulty is mainly Physics knowledge, Mathematics, practical reasoning or exam technique before regular lessons are discussed.