Teaching and evaluation are of course not the same thing, but evaluation is an important part of teaching. There is a mismatch between students’ overall desire to learn things and the moment-to-moment experience that learning is hard.

Even devoid of all the economic and social pressures that grades impose students would compromise their learning experience. Ever regretted looking up the solution to a puzzle in a video game or sneaked a peak at the crossword puzzle solutions?

One of the hardest part of teaching is keeping students from self-sabotage. Evaluation helps with that.

Beyond that evaluation is of course also useful just as feedback.