In the book Educational Psychology, Gary Peilin is located in the sixth chapter. Gary Peilin believes that students' mental skills are the result of the transformation from external material activities to perception, representation and concept, and are realized through the internalization of practical activities.

Gary Peilin believes that "intellectual activity is a reflection of external material activities" and the formation of students' mental skills "is the result of the transformation of external material activities to the reflection level-to the perception, representation and concept level." This transformation (internalization) process needs to go through five basic stages.

intellectual skills

(1) Meaning: Also known as intellectual skills and cognitive skills, it is a legal way of mental activity formed through learning.

(2) Features: First, as far as the action object is concerned, it is conceptual; Second, as far as action is concerned, it is implicit/explicit; Thirdly, as far as the action structure is concerned, it is simple and can be merged, omitted and simplified; Fourth, as far as activity requirements are concerned, students are required to master the correct way of thinking and obtain the production system.