His book Educational Psychology, published in 1877, is the earliest book officially named "Educational Psychology" so far, and its actual content is not much different from that of general psychology.
It defines the research object of educational psychology as the application of the basic principles of general psychology in the field of education. However, because it does not provide an independent subject content system, it does not mean that educational psychology is established as an independent subject. It is generally believed that educational psychology was initiated by American psychologist Thorndike.