Research on student evaluation of college teachers' performance is briefly summarized. Lawrence M. Aleamoni offers four arguments in favor of student ratings: (1) students are the main source of information about the educational environment; (2) students are the most logical evaluators of student satisfaction and effectiveness of course elements; (3) the student-teacher communication involved raises the level of instruction; and (4) use of student ratings by other students in course selection may increase the possibilities that excellence in instruction will be rewarded. Although faculty have expressed concern about the ratings being measures of popularity, research indicates that students can effectively discriminate between teaching effectiveness and other affective dimensions. Research does not support strong relationships between teacher ratings and student grades, while research on the effect of class size is inconclusive. It is noted that design of the rating forms should consider the purpose of the evaluation (formative or summative); that the ratings should be administered by appropriate departments; and that a summary of results should be available quickly. In general, individual respondents' comments should not be published. (GDC)