The research on teacher effectiveness that is reviewed in this paper focuses on teaching as behaving--the observable aspects of teaching--and teaching as thinking--the inner aspects of teaching. The section on teaching as behaving emphasizes the encouraging results of direct instruction (academically focused, teacher-directed classrooms using sequenced, structured materials), but also discusses management concerns and what constitutes effective class management, psychological conditions that create a good learning situation, and the influence of students and other context variables on teacher behavior. The section on teaching as thinking provides discussions of the teacher as a planner and as a decision maker, teacher judgment, and teachers' implicit theories and perspectives. The summary of these sections notes that teaching is a process of allocating instructional time and assigning academic tasks in such a way that students have opportunities to learn while experiencing a high rate of success and engagement time, and that teaching is a complex process involving more than just a series of discrete, unrelated behaviors. (RL)