What a deal!

An old dog learns an old trick

When I was merely a teaching assistant in graduate school, the university provided me with a paid homework grader for my calculus students. I collected homework every class day and had it to return within a day or two. Nice. Today, however, as a full-time college professor, I can only dream of such luxury.

Still, I think homework is important and that students need the practice that homework provides. I therefore encourage my students to do their homework by making it count toward their grades, even though I collect it only on exam days. I don't actually correct it. I just scan it for approximate completeness and dole out some points. Most of the students who hand it in do a decent job and get full credit:

10/10

These students are happy when they hand in their exams and pick up their high-scoring homework. (At least one part of the day has gone well.) Other students come up to me with tales of woe:

“I did my homework, but I forgot it at home.”

“I left my homework in my car.”

“My friend borrowed it and didn't give it back.”

I tell them all the same thing: Bring the homework to the next exam day and receive late credit for it. Late credit means half credit. Students did not generally seem to appreciate my generosity when I scored their homework:

Late credit: 5/10

“But I did the whole thing, Dr. Z!”

“Yes, but it was late. You should have handed it in on time.”

“That's not fair!”

“The rule applies to everyone. That is the epitome of fairness.”

“The what?!”

After more than three decades of teaching, I finally remembered a simple lesson from the retail sector. Most of us have undoubtedly heard a story about the impulse-purchase items near the grocery store checkstand. The grocer is trying to sell something—ball-point pens, or candy bars, or whatever—for 25¢, but they seem to be nailed to the countertop. No one is going for them. Then the grocer has a brainstorm. He marks them with a sign: 3 for $1. Now they fly off the shelf.

It's not the price. It's the perceived bargain.

I pondered.

The next time I scored late homework, I changed my tack:

Late credit: +5

That's right. The same number of points, but no denominator to remind anyone that it's half credit. I also made the plus sign nice and big. Students were pleased.

“Cool. Thanks, Dr. Z!”

“All right!”

“Whoa! Five more points! Thanks, Z-man!”

The Z-man says you're welcome.