It is now commonplace for students to evaluate their professors, usually by filling out bubble sheets late in the term. A typical form has a dozen or more questions, many with multiple parts. For example, one question in a form I have seen asks, "Does the instructor meet his/her classes regularly? Does he/she keep his/her office hours? Are there any regrettable irregularities in his/her behavior?"
Staff members typically enter the students' ratings into a computer and give them (without the students' names) to faculty members the following term, in the somewhat wistful hope that improvements in teaching will follow. Because the ratings often are the only evidence available about how well a professor can teach, they are also considered seriously by committees charged with evaluating the professor for retention, promotion, and tenure.
The value of students' evaluations seems clear, but opinions differ on the best ways to gather and use them. Part craft, part art, teaching is extremely complex and difficult to assess accurately. But many people both inside and outside the field believe that teaching can be evaluated with a few simple measurements. Although we cannot easily assess the art involved in teaching, the argument goes, we can measure certain behaviorslike distributing the syllabus early in the term, and being cordial during office hoursthat may be associated with good teaching. Most teaching-evaluation forms thus ask about those behaviors, as well as students' reactions to them and to the teacher's style. But nobody involved seems confident that the measurement is getting at the essence of teaching.