Similarity of student ratings across instructors, courses, and time

This study raised three questions about the similarity or generalizability of student ratings of courses and instructors. First, how stable are student ratings of the same instructor giving the same course during twodifferent semesters? Second, how similar are student ratings of the same instructor in twodifferent courses? Third, how similar are student ratings of a given course being taught bydifferent instructors? Instances were identified in which student ratings on seven different factors were available for pairs of courses for each of these questions. For the case of the same instructor — same course—different semesters, student ratings were reasonably similar (median r for seven factors about 0.70). For the case of the same instructor—different courses, the median r was surprisingly low — about 0.40. For the case of the same course—different instructors, substantial correlations were obtained for some factors and insignificant correlations for other factors. Implications of these findings for practical use of student ratings and suggestions for further research in the area are discussed.