The prevalent use of student ratings in teaching evaluations, particularly the reliability of such data, has been debated for many years. Reports in the literature indicate that there are many factors influencing student perceptions of teaching. Three of these factors were investigated at the University of Western Australia, namely the broad discipline group, course/unit year level and student gender. Data collected over 3 years were analysed. The outcomes of this study confirmed results reported by other workers in the field that there are differences in ratings of students in different discipline groups and at different year levels. It also provided a possible explanation for the mixed results reported in studies of student gender in relation to student ratings. (Contains 4 tables and 3 figures.)