Ways to interpret data from student ratings of teacher performance and approaches to maximize the use of student ratings are considered, based on the experiences of the Center for Instructional Development and Research (CIDR) at the University of Washington (UW). The use of student ratings at UW and other colleges is briefly considered, along with how student ratings can be part of a program of self-improvement of teaching effectiveness. Information on how to read UW's instructional assessment system (IAS) computer printout of standardized student ratings comments is provided, with attention to frequencies, mean rating, the percentage below good, and the relative rank. Reading students' demographic information to better able interpret student ratings is also covered. After considering data from the IAS printout, teachers can consult yellow sheets to find the students' specific comments. Sources of help to UW instructors who seek to use information provided in student ratings include the CIDR library, CIDR publications and productions, CIDR consultation services, and the Educational Assessment Center. An IAS questionnaire is included. (SW)