Teaching skills can be acquired or modified through various processes, including observation, concept acquisition, practice, and feedback. However, evidence does not indicate that combining these processes into a single training methodology provides any advantage for teacher trainees. Teaching also may be influenced by providing information about teaching skills, inducing cognitive conflict, and arranging for selective reinforcement. Although teaching skills may have been acquired or modified, their use cannot be assumed. The complexity of a skill, its acceptance philosophically, its utility in terms of student learning, and the supervisory support that it receives all influence the extent to which a teaching skill is adopted and used. To extend and refine the knowledge about these processes will require a refining of criteria to include both qualitative standards and more complex definitions of teaching skills. (Author/JD)