Saturday, February 28, 2004

Experimental labs

In my zoology lab class last semester I added in two experimental labs. This was a huge change for the course as for the past 30 years it had been a pure slice-n-dice preserved specimen lab. One of the new labs examined rat and mouse metabolic rates, and the other looked at snail locomotion. In both labs students were able to develop their own hypotheses and then designed an experiment to test their hypotheses. Nothing was preset, and by the end of both labs students had collected at least some data relevant to their original hypotheses.

The students responded very positively to the labs on the day of the lab. Both labs had live animals and just about everyone had a blast handling the animals. I gave out surveys at the end of each lab, and both received stellar marks. For both labs >90% of students enjoyed the labs at least "some," >90% thought they'd learned at least "some," and >95% said I should at least "possibly" use the labs again.

However, at the end of the semester, when I asked the students to compare the experimental labs with the dissection / anatomical labs, the students generally preferred the anatomical labs (only 19% preferred the experimental labs, 44% preferred the anatomical labs, and 37% thought they were equal). Essentially the students were saying that they preferred memorizing about 60 anatomical terms in 3 hours to working with animals while developing scientific reasoning and writing skills. I was rather befuddled.

What I suspect is that students felt that the memorization-focused labs were teaching them more. But why? And, more importantly, how can I show students that learning reasoning skills and writing skills is a (probably) vastly more important goal for this course than memorizing 600 terms that they'll forget by next Christmas? Note, I'm not saying that learning specific content is valueless, just that it seems like mixing content and reasoning is probably better.

In truth, I know that part of it is my fault. The grades in the class are largely based around tests on the memorized anatomical content, as they have been for 30 years. Thus, students in this lab probably felt, to some extent, that the experimental labs were a "waste" (though lab reports based on the experimental labs were a decent fraction of their grade). However, even in other classes I've taught where there's been relatively little memorized content on tests, students have still protested that the experimental style of learning is not "learning" at all.

One way I hope to approach this issue is to show students more about how real science is done. Thus, I've added a new lab this semester entirely on scientific writing, the scientific method, and journal articles. I hope this new lab, as well as an expansion of the experimental labs, helps students see that the ultimate goal of science is to learn more about the world, not just memorize what's already known.

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