Here is a link to a short video in which Sue Kirch, a science educator at New York University, discusses the question: Can elementary school students engage in scientific reasoning? See my 9/29/08 entry, for a summary of Sue's recent presentation at the Nonfiction Institute at the University of Maine.
http://steinhardt.nyu.edu/videos/susan_kirch
Click on "comment" at the bottom of the entry to read Sue's response to questions I emailed her after I viewed her video. If you have questions for Sue, feel free to post them on the comment page & she'll respond.
Friday, October 17, 2008
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1 comment:
Hi Penny,
Thank you for posting my video on your blog site! In an email, you asked me a couple of questions about the details of one of the experiments I described: "Why were the meal worms going to the wet area? How was it figured out it? How did that come about & was figured out?" and it seems appropriate to address them here in this blog entry since others might have similar questions.
Students were studying a variety of soil invertebrates (pill bugs, centipedes, millipedes, beetle larvae) in playground studies and standardized classroom critter studies (e.g., mealworms - darkling beetle larvae). They conducted many independent investigations, but one whole class investigation was to check and see if the mealworms preferred ("liked") a wet paper towel (or desk or dirt) or a dry paper towel (or desk or dirt). It was a whole class investigation only because every one was interested in the question and it was convenient to do the investigation together. When all the groups tested their bunch of mealworms many found that the mealworms "liked" both the wet and dry paper towels. This was contrary to some of the predictions and expectations since the instructions for the mealworm habitat (a box with oatmeal or grain) are that it should not be allowed to get wet.
The students had determined that the criteria for "liked" would be if the mealworms crawled onto the paper towel. So, when they saw the mealworms on and around the wet paper towel one group thought the mealworms might be thirsty. There was a lot of skepticism voiced for this explanation, because their classmates did not believe we could actually see mealworms drinking to prove they were drinking. In the class discussion this skepticism was verbalized as: "How do you know?"
"How do you know that it has a mouth?"
"How do you know it was drinking?"
“Did you see it?”
I, and the teacher, was puzzled a bit by the observations too, but the students’ explanation that the mealworms were thirsty seemed reasonable to me and I got to wondering why. When I checked-in the following day I realized that the class had not been providing the colony with a bit of fresh potato or fruit each day as a source of water! So, it now made perfect sense that the larvae were probably pretty darn thirsty. If we had conducted the experiment with larvae that had received plenty of food AND water we probably would have seen their preference for the dry paper towels/table/dirt rather than the outcome we did see (no preference, attracted to both). With thirsty worms, they appeared to like the wet paper towel (which in our model represented the environment, not a food/water source) because they were thirsty, not because they like to live in a wet environment.
I told the teacher and we all felt so bad for our mealworms and got them a water source immediately!!
You should now ask, “What happened when the students conducted the experiment again after the parched mealworms had their thirst quenched?” I am very sorry to report that we did not run the test. Why? We the teachers did not mediate the follow-up investigation. Why? There’s another essay I should write about the role of time, choices and vigilance in school science.
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