If you never look at a topic again after studying it, you forget most of it over time. One way to reduce this is to spread reviews over intervals. This is called spaced repetition.
The idea is simple
Instead of repeating a topic many times in one sitting, you review at widening intervals such as days, weeks and months. Reviewing just as you begin to forget makes it easier to keep the information in mind.
A sample schedule
- The day you learn: study the topic and take a short test.
- The next day: look at your notes and re-solve your mistakes.
- A week later: solve a few questions on the topic.
- A month later: check the topic in a general review test.
Test yourself
When reviewing, instead of just reading the notes, close them and try to recall. Trying to recall is generally more effective than reading again.
How do you apply it in practice?
- Write the topics you studied on a list with their dates.
- At the weekend, set aside a short review block on the previous week's topics.
- Add the questions you got wrong to your mistake notebook and re-solve them at intervals.
Everyone forgets at a different speed; the schedule above is a start, and you can adjust it to your own situation.