Despite questions about their reliability and validity, student evaluations of teaching (SETs) are a primary measure of instructor performance. The current study examines SETs, including a thorough list of potentially relevant variables. The findings suggest that how much students perceive they learned in a course is an important predictor of SET scores. Further, a number of variables outside of the instructor's control appear to introduce bias into SETs. Nonetheless, social work norms imply the necessity of seeking input from students. Suggestions are given for possible methods of dealing with this dilemma, and for needed future research. (Contains 4 tables.)