It was a mistake to do the review on the same day! The scientifically correct timing for reviewing

Learning Method

This section explains how to study to achieve your goals in an efficient manner.
This theme is also about the timing of the review.
Please check it with the previous article.
勉強のしすぎは、長期的な学習には効果的ではありません。

Not if you review it right away.

Intensive learning is a method of studying that involves reviewing what you have learned immediately.
If you have a test tomorrow on something you learned today, this will work very well.
So, if there is still time before the test, how should you review?
Also, what should I do if I have a very large area to review, such as an entrance exam?
It is impossible to review the entire scope of the test right before the test, so you need to make a plan for reviewing.
What is the best way to plan for efficient review?
Here's a psychological experiment that tackles this problem.
It was published in 2008 by a research group in the United States.
Cepeda, N. J., Vul, E., Rohrer, D., Wixted, J. T. & Pashler, H. P. (2008) Spacing effects in learning: A temporal ridgeline of optimal retention

Participants in the experiment first learned to memorize history and other information, and then reviewed it after a while.
The interval between learning and reviewing is called “Interval 1”.
After some more time, we gave them a test to see how well they remembered the answers to the questions.
The interval between the review and the test is called “Interval 2”.
What is the best test score when interval 1 and interval 2 are equal?
Looking at the results, first of all, we can see that regardless of the length of interval 2, the effect of review is the least when interval 1 is 0 days, i.e., intensive learning where learning and reviewing are done continuously.
The most important aspect of the results is that the test scores get better as interval 1 gets longer, and then gradually get lower after a certain point.
When interval 2 is 5 days, the tendency is more apparent.
Reviewing after a certain appropriate time interval is called “distributed learning.
The technical term for the improvement in test scores with this method of learning is called the variance effect.

Research on the best time to do a review

Experimental Methods

Participants in the experiment were asked to memorize historical facts (32 questions in total).
I reviewed the material some time after learning it.
The time between learning and reviewing was called “interval 1” and ranged from 0 to 105 days.
In the review, we studied the exact same problem.
Some time after the review, a test was given to see how much I remembered.
The time between the review and the test was called “Interval 2” and was set at 7 days and 35 days.
A total of 1,354 people from various countries participated in the experiment via the Internet.
The participants were divided into groups according to the length of interval 1 and interval 2.

experimental results

The horizontal axis is interval 1, i.e., the number of days until you start reviewing.
The vertical axis is test scores.
The graph shows the scores of the group with interval 2 (the number of days between review and test) of 7 days and the group with interval 2 of 35 days.
When the test was 7 days away, students scored higher if they reviewed within a few days, and when the test was 35 days away, students scored higher if they reviewed 10 days later.
When interval 1 was “0 days,” i.e., intensive learning with immediate review after learning, it was the least effective.

1:5 law

When is the best time to review (Interval 1) to get the highest test scores?
The answer is that Interval 1 and Interval 2, where good scores are obtained, are related to each other.
In other words, if the interval between review and test (interval 2) changes, the interval between study and review (interval 1) will also change.
From the resulting graph, we can see that the ratio of interval 1 to interval 2 should be about 1:5.
One more important thing can be read from the resulting graph.
This means that even if you miss the best time to review, the benefits of reviewing can be huge.
If the test takes place 35 days after the review, then reviewing about 10 days after learning is most effective.
However, even if you review it 20 days later, you can still get a reasonably high score.
This is the “dispersion effect.

All you need to worry about is when to review it first.

If I have multiple opportunities to review before the exam, when should I do so?
In the past, it was thought that review was more effective if it was done in gradual intervals rather than evenly spaced.
This is because my instincts told me that I should review frequently when my understanding and memory of the content was unclear, and when my understanding of the content had improved, I should space out the review.
However, an experiment conducted in 2007 showed that the conventional idea that “a gradual review method that extends the interval between reviews is good” is not necessarily correct.
Look at the results of the following study.
Karpicke, J. D. & Roediger III, H. L. (2007) Expanding retrieval practice promotes short-term retention, but equally spaced retrieval enhances long-term retention.
This study compares whether it is better to increase the interval between reviews gradually or evenly.
The point is that I changed the interval between the last review (=quiz 3) and the final test.
When the time until the final test was short (10 minutes), the “Gradual Interval Increase Method” was more effective.

However, when the final test was given two days later, it was found that the “evenly spaced review method” was more effective, i.e., the students were able to get higher scores on the final test.
“The conclusion is that you will remember longer if you review at even intervals than if you gradually increase the intervals.
Why is it better to review evenly?
In fact, the timing of the first review was key.
Looking at the time between learning and the first review (quiz 1), the “even review” method is longer than the “gradual review” method.
Intensive study, where students review immediately after learning, may be effective for the most recent test, but not for tests that are much further in the future, such as entrance exams or certification exams.
The “Gradual Interval Method” had this intensive learning effect, which was weakened when the time before the final test was extended.

Research on optimal review intervals

Experimental Methods

The participants in the experiment learned to memorize the words.
After that, three quizzes for review were given at intervals.
The final test was given ten minutes after the third quiz, or two days later.
Review intervals were set at 1-5-9 (gradually increasing) or 3-3-3 (evenly distributed).
The numbers represent the number of days.

experimental results

In the case where there were two days between the last review (quiz 3) and the final test, the final test score was higher using the “review evenly” method (5-5-5) than the “extend the interval between reviews” method (1-5-9).

What you need to know in order to study efficiently

  • Decentralized learning” is the most effective way to review after a while.
  • The best ratio between “first study to first review” and “first review to test” is 1:5.
  • The second and subsequent reviews should be done evenly until the test.