From Stanley Fish…

The relationship between present action and the judgment of value is different in other contexts. If a waiter asks me, “Was everything to your taste, sir?”, I am in a position to answer him authoritatively (if I choose to). When I pick up my shirt from the dry cleaner, I immediately know whether the offending spot has been removed. But when, as a student, I exit from a class or even from an entire course, it may be years before I know whether I got my money’s worth, and that goes both ways. A course I absolutely loved may turn out be worthless because the instructor substituted wit and showmanship for an explanation of basic concepts. And a course that left me feeling confused and convinced I had learned very little might turn out to have planted seeds that later grew into mighty trees of understanding.

And that is why student evaluations (against which I have inveighed since I first saw them in the ’60s) are all wrong as a way of assessing teaching performance: they measure present satisfaction in relation to a set of expectations that may have little to do with the deep efficacy of learning. Students tend to like everything neatly laid out; they want to know exactly where they are; they don’t welcome the introduction of multiple perspectives, especially when no master perspective reconciles them; they want the answers.

But sometimes (although not always) effective teaching involves the deliberate inducing of confusion, the withholding of clarity, the refusal to provide answers; sometimes a class or an entire semester is spent being taken down various garden paths leading to dead ends that require inquiry to begin all over again, with the same discombobulating result; sometimes your expectations have been systematically disappointed. And sometimes that disappointment, while extremely annoying at the moment, is the sign that you’ve just been the beneficiary of a great course, although you may not realize it for decades.