Change of plans

Around four or five this afternoon I got back from a trip to Belmont University this past Friday (great trip, fun talk, good friends, etc.), and went right up to my office to pick up the MATH 280 homework that was to have been shoved under my door. 23 out of 36 students had submitted their work "on time," and two more slyly slid their work under my door while I sat there grading Calc II quizzes.

I held off on grading the 280 homework (a set dealing with set equality and properties of set operations, like commutativity and associativity of union and intersection, and so forth) until I got home. Dinner made, I then settled into my chair to start.

The first problem was rough (the proof I'd requested has a more subtle structure than do the others in the set), and I'd expected that. The second, though, was rougher, and this I'd not expected. Several people did fantastically. Several others had the right idea but their exposition was ragged and raw. Several more still, though, had only a very loose grip on the problem.

I stopped grading there, knowing that were I to keep going, I'd see more of the same. After all, these kinds of proofs (of set equality) are tricky at first, but they're also very formulaic, and once you've got one of its kind, you've got 'em all. I'm almost certain that whatever mistakes a student made on Problem 2, she'd repeat on Problem 3, and again on Problem 4, and so forth. I doubt it would make much difference were I to keep commenting.

Rather than finish off this problem set, I'm going to return the ungraded homework sets tomorrow, giving students the option of revising their work after we've had a chance to go through a variety of approaches to Problem 2 together at the outset of class.

We'll see how it goes.