Four traditions of reform in 20th century U.S. teacher education are described: academic, social efficiency, developmentalist, and social reconstructionist. Each tradition is illustrated with examples from both early and contemporary teacher education programs. Following the presentation of the reform traditions, the heuristic value of the traditions framework is illustrated by applying it to a discussion of current reforms centered on reflective teaching. it is argued that this framework of reform traditions can help clarify some of the important differences between reform proposals which appear on the surface to be alike. (Author)