Monday was the science fair at school. Chloe had her project all ready (no last minute prep!), and it was pretty cool. Her hypothesis was “Touching school books to do homework will make your hands just as dirty as coming home from school and not washing your hands.”
As I helped her with the experiment, we came to the conclusion that the only practicable way to compare the microbe growth was to simply estimate the percentage of the agar surface area covered by colonies. Since she was going to be estimating, I suggested that we blot out the identifying information on each Petri dish photo, to avoid biasing the estimate. Do you know how difficult it is to explain bias and blinding to an 8 year old? Actually, if you’re a skeptic you probably do, because I think the general populace tends to have a similar uncertain idea of what it’s all about. At first she thought I was talking about lying. It took a while for the idea to sink in for her – we can perceive and remember things differently depending on our expectations. (No, I did not have her read the Alexander Skarsgard post!)
In any case, I think the blinding served its purpose, since the results came up inconclusive. In a way, I think this is better than the experiment coming out “right” and 100% confirming the hypothesis. I’m so glad the fair guidelines emphasis that even a failed experiment does not equate with a failed science project, and students should analyze what happened and put it in the report. In our case, the experiment didn’t fail as such, but the inconclusive results led her to think about ways we could redo the experiment and get a clearer answer, and what factors might have influenced the outcome. She now has first-hand experience that a small sample size means you can’t really rely on the results! She also had some great ideas about variables that might have influenced the bacteria growth, like how much homework she had, whether some of it was on the computer, and even whether she rode a different (perhaps germier) bus home from school on a particular day.
As it turned out, she didn’t win any prizes, and we were both a little bummed. But this project has taught her so much – clearly she’s learning to think about things in a scientific way. She’s been introduced to the idea that our perceptions can be tricksy, and science involves avoiding perceptual pitfalls. She learned about translating her observations into concepts and sharing those concepts with others – probably the hardest part of the project. She struggled with writing the report, but persevered. And maybe best of all, she learned to work on a school project a bit at a time and get it done with plenty of leeway, so it wasn’t too stressful!
The other thing that makes me proud is that her reaction to losing was to be a little upset for a few minutes, then start planning for next year’s project, and pondering how to make it a winner. She has great spirit! Unfortunately her current idea is a hydroelectric generator that powers a “water volcano,” which will . . . power the . . . um generator. Yeah, it’s a perpetual motion machine. But hell, plenty of intelligent people have fallen into that trap. I told her to write down all her ideas, and we’ll talk about them as we get closer to the next fair. At some point I’ll talk to her about systems running on energy, and for instance sound being an emission of energy – so if the hydroelectric generator makes sound, that means energy is leaving, which means eventually . . . I’ll try to be all Socratic and let her figure it out. It’ll be fun.