A new study concludes that students do not rank teachers highly because they’ve actually learned things from them:

How does a university rate the quality of a professor? In K-12 education, you have standardized tests, and those scores have never been more widely used in evaluating the value added by a teacher.

But there’s no equivalent at the college level. College administrators tend to rely on student evaluations. If students say a professor is doing a good job, perhaps that’s enough.

Or maybe not. A new study reaches the opposite conclusion: professors who rate highly among students tend to teach students less. Professors who teach students more tend to get bad ratings from their students — who, presumably, would just as soon get high grades for minimal effort.

The study finds that professor rank, experience and stature are far more predictive of how much their students will learn. But those professors generally get bad ratings from students, who are effectively punishing their professors for attempting to push them toward deeper learning.

I mean, sure, students recognize quality when they see it. Most of the time. But that leads to a question of principles: when you do recognize superior teaching–an excellent, challenging, time-consuming class–do you risk the B or C in order to learn, when you know you can get an easy A elsewhere? It takes a serious dedication to one’s principles to go that route. And that’s not even counting the people who just want to pay their four years’s worth of dues as quickly and cheaply as possible and get out.

The study is interesting for its longitudinal attention. Apparently students do worse in challenging classes, but better in subsequent ones; and better in easy classes, then worse in subsequent ones. Like, duh. This is the kind of thing that makes me create a new category of blog post: “science or common sense?”