## Forgetting curve and Spaced repetition

At the end of the 19th century, German psychologist German Ebbinghaus developed the theory of the Forgetting Curve.
According to this theory, forgetting occurs in accordance with the chart in the figure below.

Simply put, today we will forget 10% of what we learned yesterday, tomorrow another 15%, 20 more the day after tomorrow and by the end of the week, we will remember only 10% of the learned information.

The numbers are not accurate. For a different kind and a different amount of information, the percentages will be different.
But specific numbers are not important.
The main thing in principle: we forget and forget in increasing order.

How to deal with the forgetting curve?

A spaced repetition method has been developed. Means repetitions at increasing intervals.

In particular, spaced repetition is used in Pimsler courses.

Repetition intervals can be, for example, 10 minutes, 1 hour, 5 hours, 1 day, 2 days, 5 days.

But some researchers say that repeating at regular intervals shows not the worst, and, sometimes, better results.
I.e. instead of distributed repetition (above), we repeat the same number of times (6) each next day.

We recommend the following basic course repetition scheme:
1, 2, 1, 2, 3, 2, 3, 4, 3, 4, 5, 4, 5, 1, 2, 3, 4, 5, 6, 5, 6, 7, 6, 7, 8, 7, 8, 9, 8, 9, 10, 9, 10, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, etc.
I.e. after each lesson, we go back one lesson, after every lesson multiple of five we go back 5 lessons, after each lesson multiple of ten, we return 10 lessons back.
All twenty-five lessons must be completed in 5 days - 5 lessons per day, and the last two days we devote to repetition, starting from the first lesson.

This repetition pattern will be effective if we practice with maximum intensity.
If we do it one hour a day, we just allocate half an hour every day to repeat the material that has been learned over the past week.

We also see now why the study of 10 minutes a day does not make sense: we do not have enough time even to repeat the material already learned.