In the mid and late 1950s, Drs. Eli Robins, Samuel Guze, and George Winokur met often to discuss an approach to psychiatry that later became known as the medical model. This model was based on the belief that the scientific method was the appropriate vehicle for advancing the field. The importance of reliable diagnostic criteria for psychiatric disorders was emphasized. Research training was integrated into the residency training program. A series of studies was conducted that resulted in the development of psychiatric diagnostic criteria, which were summarized in the historic 1972 article "Diagnostic Criteria for Use in Psychiatric Diagnosis" by J. Feighner, E. Robins, S. Guze, R. Woodruff, G. Winokur, and R. Munoz (Arch Gen Psychiatry 26:57-63). In 1974, the first edition of Psychiatric Diagnosis by Woodruff, Goodwin, and Guze (Oxford University Press) was published. Dr. Guze summarized the concept of the medical model in Why Psychiatry is a Branch of Medicine (Oxford University Press), published in 1992.