If you enjoy the pieces I write about education and learning, then I highly recommend joining The Nature Institute and receiving their newsletter, “In Context”. They are kindred souls exploring the same ground in a very articulate way. I respect their work a lot. (Send some money to The Nature Institute, 169 Route 21C, Ghent, NY 12075.) I would like to share a wise quote from their latest newsletter but I wish to put it in context of a specific learning experience I’ve been having at Chrysalis.
I read that ailanthus leaves are alleopathic; they contain chemicals that inhibit the growth of surrounding plants. An experiment was suggested in which radish seeds were sprouted in both tap water and water in which ailanthus leaves had soaked for several hours. I tried the experiment with my students; I wanted them to prove that ailanthus leaves were alleopathic.
The first experiment was suggestive of this result. Each student had two vials, each containing 10 seeds being soaked in either tap water or ailanthus tincture. My vials definitely had a difference in onset of sprouting. However, by the time students brought back their vials the next week, the ailanthus tincture seeds were catching up (perhaps because the radish seeds had grown as much as they could within the confines of a vial). The tap water seeds were about 30% longer than the ailanthus tincture seeds but there was lots of variation. The difference was not significant.
I could imagine two reasons for this. Either students at home ran out of ailanthus tincture and had to use tap water in the last days of the experiment or because the experiment ran too long. So I devised a second experiment. This time we left an ailanthus leaf in the vial of tincture so that if students ran out of tincture, they could make more by simply adding more water to their vial.
In this experiment, the ailanthus tincture plants grew about 5% longer. Again, there was a lot of variation. So now there was real confusion. Surely some of it was experimental procedures because my vials always showed a pronounced difference. But there was the undeniable fact that the ailanthus tincture seeds had actually grown longer in this experiment. Our interpretation of this is that the leaf left decomposing within the tincture solution provided nutrients that assisted the sprouts once they had sprouted. My sense was that the ailanthus leaves did have an alleopathic effect but how to bring this into significantly observable results?
This led to a third experiment. We changed the sprouting method to make it more uniform and we ran the experiment for only three days. This time, the results were profoundly different. The 330 tap water radishes had roots 11 mm long while almost all the 300 ailanthus tincture radishes did not sprout, leading to an average of .04 mm for them. At last, we had proved it.
While this third experiment was running, I received my copy of “In Context”. The article “What Do Experiments Prove?” by Craig Holdredge had the following profound quote.
“The more experiments we carry out, circling a phenomenon and investigating it from different angles, the better we can see the modifications that occur with changing conditions. Our understanding of the phenomenon grows. But we also grow, gaining inner flexibility that helps us to expect the unexpected and appreciate the uniqueness of a new situation, as well as to modify our previously gained knowledge to fit the new situation. In this way experimentation becomes a way of training flexibility in thought and judgment, which, in the long run, is much more essential than believing one has “proven” something through an experiment.”
I really like this quote. It speaks to an area of dissatisfaction I’ve felt with my teaching at Chrysalis. Too often I have led the class in experiments with the aim of “proving” something. These experiments too often lacked the joy and spontaneous discussions I experienced with earlier class experiments. And, most fascinating, the experiments very often did not prove the intended result because of the interaction with other variables. If I and the class have a mindset of “proving”, then the results are a setback rather than a creative jog toward shifting insight.
The world is much more interconnected and complex than we often acknowledge to our students. Too often the scientific method and recipe experiments lead us into thinking that (a) other variables are “bad” because they taint results and therefore need to be controlled and that (b) specific “conclusions” can be thought of as existing independently of other conclusions or relationships.
The difference is between learning that ailanthus leaves are alleopathic and deepening one’s understanding that the story of each seed is unique: that the story of each seed depends upon its parents, the surrounding vegetation, the history of the square inch it fell upon, etc. One’s awareness of a tapestry of vast mystery grows rather than simply a certain confidence in knowing one strand without even being aware it fits into a vast tapestry. Another way to express the difference is that the proving experiment would probably stop there. The other frame of mind can easily lead on into scores of related experiments.
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