In a recent post, Parrhesia suggested that course grades should be 100% determined by performance on a final exam—an exam that could be taken repeatedly, with the last attempt being the course grade. (See also the discussion at r/slatestarcodex.) The idea is that grades are supposed to measure what you know, and if you do well on a final, then you know the material.
Ha. Haha. Hahahahahahahaha.
Now, I sympathize with this proposal. I largely agree with the central claim that this would be more accurate than grades based on a mixture of homework and quizzes and whatever.
And yet—I suspect this proposal hasn’t seen much contact with people who’ve actually taught classes. Systems with humans in them behave in funny ways, which means there are other considerations beyond accuracy.
I don’t mean to suggest that things are optimal the way they are. But we should at least understand how they came to be, so let’s follow Chesteron’s fence for a while, shall we?