The effect of distraction is better than that of concentrated review. Especially the more difficult learning materials are more suitable for decentralized review. Pay attention to the following three points and give full play to the advantages of decentralized review: ① Decentralized review must have certain preconditions. Time is limited, so we can't divide the time too finely and the interval too long. It is best to combine dispersion and concentration. "(2) time should not be too scattered, we should pay attention to the principle of timely review. Generally speaking, the dispersion method of pure memory materials is better, which is more suitable for students with poor learning ability.