The Woes of Teaching Evaluations

Competitive markets yield efficient outcomes. But efficiency requires information. In a competitive market, a store that sells bad products will go out of business, but if people do not have information about the quality of the product they are buying, the store can sell this bad product and make a profit.

Universities are in the teaching business. Once a semester, students (if present in class to do so) fill out forms which evaluate their professors and TA’s. So why not make this information public?

It could be that these student evaluations provide such bad quality of information that it is worse than no information at all. It has been argued that student evaluations are “Inaccurate, demeaning and misused”, see this survey done by Mary Gray and Barbara R. Bergmann.

It could also be that there is an incentive problem? An argument against using student evaluations all together was put forth by Curtis Eaton and Mukesh Eswaran in their paper on “Differential Grading Standards and Student Incentives”, that grading standards are not uniform across disciplines. So if students give better evaluations to easy markers, it could mean that professors have an incentive to inflate grades. Economics tells us to think about missing markets and resulting inefficiencies. The absence of official teaching evaluations creates a market for unofficial ones; most popular is ratemyprofessors.com (complete with revenue-generating ads). Ratemyprofessors.com, provides a valuable service. It is at least some way of getting information on potential professors you may encounter.

Some argue that ratemyprofessors is biased as only students who love or hate a course will contribute to the ratings. This is a professor-centric view. Ratemyprofessors is written by students for students and a typical (rational) review should be useful. For example, one of us has been rated in a course that we never taught.

The only way to prevent students from relying on websites such as ratemyprofessors is to provide alternative and better data. Maybe, if teaching evaluations were published, students would take them seriously, because they know their ratings will guide future students' choices. Of course, that better data would have to respect students' and professors' legitimate privacy concerns. But since keeping an evaluation private signals that you might have something to hide, will people choose this route? Any student-generated measure faces a specific problem, that students by definition do not have specialized knowledge of the material they are being taught.

The fundamental problem in the educational market place is information: how can you tell if your teacher is a lemon? I wish I had an answer for that one. I don't even know if public teaching evaluations would help more than they would harm.