I'm continually amazed by the curiosity and fascination of my students. They are quite often drawn to the simplest of challenges, wanting to find out what "right" is, more than save face.
I've been talking about the processes that bring water from the roots up to the leaves of a plant, in very broad terms. I introduce guttation as a process that brings water to the surface of the leaf in liquid form, and transpiration as a process that brings water to the surface of the leaf in vapor form.
I asked the students today what the difference is between the two processes. The goal of the question not being able to say what each does, but how they differ. It's a subtle difference, but exposes exactly the memorization vs understanding conflict.
A girl stood up, and almost on cue read the definitions off the board, confident in her ability to see the difference between the definitions. I said, "Good, you can read the definitions. Now, what is the DIFFERENCE between the two?" Usually a blank stare or smile creeps across the student's face, as if to say "What, you actually expect us to believe you can grade us on anything but the definitions?"
But this was different. She immediately responded, "Well, transpiration is what happens when water evaporates and guttation is when it doesn't." Perfect! However dumbed down my definitions were, I found a subject that challenged their ability to truly understand. And when this student got it, she was (expectedly) unimpressed with her relatively informal answer. 95% of the time, I get the first answer. But the other 5% of the time, I get some truly insightful if often erroneous answers.
But I held her response up as an example of thinking about the information and using your own words to explain the relationship.
In my next class, I had a few "aha" moments when I was able to sit down and explain a couple of questions. But by far, the best moment was at the end of the lesson, explaining the same two concepts. I asked if it was clear, and they said in response, "No, it's dark." This wasn't a language thing. They were just playing with me. Being my favorite turma, they knew they could. But they emphasized that they didn't quite understand. I thought for a moment, then called on one of my best and most cooperative students.
"Come here", and he did. "Let's say you're a plant," as I faced him toward the amused class. "Now, you need what three things?"
"Water, carbon dioxide and solar energy."
I placed my well-known water bottle on the ground in front of him and announced that I was the sun. I said that transpiration and guttation are responsible for bringing water to the leaves so they can make food (through photosynthesis). I explained that I was the sun during the day (waving my hands wildly to the delight of the class) and the plant was receiving my energy. I asked the class whether his leaves needed water.
"Yes!"
My "plant" grabbed the water and brought it up to eye level. Then, I had the plant put the water back down, turned around and "going to sleep", said that it was night. Does the plant need the same amount of water?
"No!"
And what's responsible for bringing water to the leaves? "Guttation, transpiration." So do these processes happen as much during the night?
"No!"
"Is it still dark?" I ask.
Laughs, smiles. The plant sits down.
"No, it's clear, teacher. We understand now."
Since the students look to understand, though they know it risks not being fully informed, it really is my responsibility to make sure concepts are understood, even if only a couple students are listening.
Peace
John
