Jonathan and others, an American educational psychologist, put forward a new classification standard of knowledge types according to the constructivism theory, which divides knowledge into three categories: knowledge in well-structured fields (that is, knowledge based on concepts and skills), knowledge in poorly-structured fields (knowledge based on interconnection) and knowledge in fine-structured fields (schema knowledge).

For example, the usual physical and mathematical problems can be considered as well-structured problems; Writing a composition, planning an activity and running a company to make it profitable are all considered structural problems.

Psychology is like a bush. There is no shortage of concepts and theories in psychology.