If an item has a high median score, but raw scores cluster at the high end and the lower end of the distribution, it means that a number of students disagreed with the high assessment given by the majority of the class on that item. The 3-SET system computes the quartiles of scores for all other instructors who have used common items. Department chairs, TA Coordinators and Course Coordinators may also use these data to compare performance across instructors. The number of students responding, out of the total course enrollment, is a very important figure in student evaluations. In other words, the score for any item might be higher or lower if a larger proportion of the class had participated.
Statistical reliability is also very weak if the class size is extremely small.
For this reason, classes with enrollments of less than ten students will not be evaluated using the 3-SET system unless there is a compelling reason to do so. The staff of the Center for Teaching and Learning helps instructors create open-ended questionnaires for small classes. Responses to these questions can be useful, in a very general way, for interpreting the evaluation results. Fourth-Year students are taking the class, the more advanced students might give the course lower ratings because they find it less challenging. Similarly, if student GPAs in the class are higher or lower than the norm for previous semesters, the ratings may vary from those received in the earlier classes.