What is spaced repetition? How to space out your reviews
Learn the origins of spaced repetition, how to combine it with active recall, and how MemorizeKit schedules your reviews.
What is spaced repetition, and where did it come from?
Spaced repetition means revisiting learned material in sessions separated by time. Its purpose is to support long-term retention. In adaptive review systems, difficult material returns sooner, while material you remember well can wait longer. See spaced repetition on Wikipedia .
The scientific foundations include Hermann Ebbinghaus’s research, published in 1885. In his experiments on repeated learning , he examined the benefits of distributing repetitions across several days. In the 1970s, Sebastian Leitner developed a practical flashcard approach: the Leitner system , which groups cards for more or less frequent review according to recall.
Spaced repetition is a learning method implemented through different schedules and algorithms. There is no single ideal interval for every learning goal: Cepeda and colleagues’ 2008 study found that the best gap between study sessions depended on how much later the material needed to be remembered.
How do you apply it when learning?
Suppose you have learned put off — to postpone. Instead of finishing with it after one session, you return to the phrase on later days. An illustrative schedule could be:
| Day | Activity |
|---|---|
| Day 0 | Learn the phrase |
| Day 1 | First review |
| Day 4 | Second review |
| Day 11 | Third review |
This is an example, not a universal formula or MemorizeKit’s default schedule. If recall is difficult, check the meaning and example, then allow an earlier review instead of automatically extending the interval.
Combine this with active recall: each time the card returns, try to answer before revealing it. Spaced repetition determines when you review; active recall describes what you do during the review.
How does MemorizeKit support spaced repetition?
You do not need to set a review schedule for each word yourself. MemorizeKit tracks each term’s schedule and uses your practice results to determine the next review.
- A schedule for each term: Words and phrases in the same Lesson can become due at different times.
- Feedback from practice: Flashcard results with Track progress enabled and results from Learn help the system adjust your schedule. It may include reinforcement reviews before extending the interval.
- Due content in view: My Library and Lesson pages show how many terms are due and provide a Review Now action.
- Memory levels to follow progress: Terms have memory levels that help you see how learning is progressing alongside their review timing.
Start with the content that is due, attempt recall, then check your answer. Browse English Lessons and choose a topic to begin with.