The findings of eight reviews of process-product studies are synthesized. Results are organized under the main headings of time, instructional organization, monitoring, management, instruction, and environment. The paper begins with a brief history of research on teacher effectiveness, a description of the process-product paradigm, and a discussion of some of the problems characterizing this type of research. The studies suggest that the effective teacher (primarily of low SES children in the primary grades) is one who (1) uses time efficiently, keeping students engaged with task-related activities; (2) organizes students into medium to large groups for instruction, (3) correctly monitors work while being available to provide answers to student-initiated questions; (4) assumes the role of a strong leader; (5) asks low-order questions, ensures that students have the opportunity to learn sufficient amounts of content, keeps interaction at a low level of complexity, structures lessons so that students are aware of objectives; and (6) sustains a classroom environment that is warm, friendly, democratic, and relatively free of disruptive behavior. (Author/CTM)