Complementarity and individual difference are two important concepts in pedagogy, and they have obvious differences in meaning and function.

Complementarity mainly refers to the characteristics that different body abilities can compensate each other. This complementarity first exists in different aspects of physiological functions, such as the hearing of the blind is usually better, and the eyesight of the deaf-mute is often better. In addition, psychological function and physiological function are also complementary. For example, people with physical disabilities and strong will can make up for their physical defects through willpower. In the teaching environment, the principle of complementarity can help students develop their strengths and avoid their weaknesses, learn from each other's strengths and highlight individual development.

Individual difference refers to the difference in the development speed and level of the same aspect. This difference is reflected in the gender, age, physiological characteristics and psychological characteristics of individuals. For example, from the group point of view, the gender difference between men and women is the first manifestation. In addition, the speed and level of physical and mental development of each individual are also different. Some people may be precocious in some aspects and late in others. The principle of individual differences requires teachers to teach students in accordance with their aptitude, respect the individual differences of each student and carry out targeted teaching.