The book examines the basic theories of teaching in terms of their capabilities in controlling the cognitive activity of students. The central place is given to the theory of phased formation of mental actions. Based on the generalization of a large number of experimental data, the author shows the high effectiveness of this theory as the psychological basis for managing the process of assimilation of knowledge. The book is designed for specialists in the field of psychology, pedagogy, methodologists. It will be useful to teachers of secondary and higher schools, as well as to everyone interested in the problems of managing the process of assimilation of knowledge.