This semester, I’m teaching Zoology 101 labs (Intro to Zoology for nonmajors). I’m enjoying my self a lot, and it’s a class I’ve wanted to teach for a while. Right now, though, I’m grading quizzes and not enjoying life too much. Most of the scores absolutely suck, and I’m trying to figure out how much of that is the result of me setting the bar too high, how much is the result of me sucking at teaching, and how much is entirely due to other factors.
The quiz in question was on diffusion and osmosis. These aren’t the easiest topics for non-majors, and they aren’t all that interesting, so I wasn’t expecting too much – or so I thought. Apparently, I was wrong.
A little background – a week before taking the quiz, the students observed diffusion and osmosis in action by placing nematodes in a range of solutions. When the nematodes were placed in a solution with a higher salt concentration than their normal environment, they lost water, shriveled up, and died. When they were placed in distilled water, which has a lower concentration than their normal environment, they eventually swelled up and burst. This would, we hoped, be a memorable demonstration of the passive diffusion of water through a semi-permeable membrane (= osmosis).
We discussed all this before we started the lab. At that time, several of the students asked me to define “diffusion,” “osmosis,” “hypertonic,” and “hypotonic.” I didn’t define it for them. Instead, I told them that they should look up those definitions and get in touch with me during the week if they were having problems understanding them. I also told them that they might be asked to define some of those words on a quiz that they might have next week.
There were two versions of the quiz (I’m teaching two sections) and each version asked for definitions for two of those terms. So far, about 25% of the class has managed to define one correctly, and about 10% of the class defined both.
Was I unreasonable to make them look up the definitions for themselves? I thought doing it that way, particularly after being told there might be a quiz, would increase their chances of remembering the definitions. Or was it just unreasonable to expect that they would actually do the homework?
I’m honestly looking for feedback on this one – it’s not just venting this time.