models of forms - flop or success?

Last year in UE1, one of the activities was filling out a table with different forms of energy, and the evidence that each form is there. Teachers found this useful because the standards often ask them to teach some set list of forms, and the table helped them contextualize this list and recognize that it is constructed, rather than given by authority. However, one aspect of this table seemed like it was not particularly productive: The focus on evidence as the main indicator of a form led to what I considered to be an overemphasis on what was or was not observable, with teachers questioning whether a form could even exist if you couldn't observe it (e.g. does sound energy exist if you can't hear it?). To me, the defining characteristic of a form of energy is not whether you happen to be able to observe it, but what your model is for what's happening in the physical system when that form is present. In some cases that model overlaps with the evidence (e.g. for kinetic energy, the model is that something is moving, and the evidence is generally that you observe something moving), but in other cases it's very different (e.g. for thermal energy my model is that molecules are bouncing around, but the evidence is that you have a reading on a thermometer or you feel warm). To address this, I suggested that we add an additional column to the table for "model". Lane and Lezlie offered an additional suggestion to split the evidence column into "evidence for the presence of this form" and "evidence for change in this form", since in some cases we tend to observe the presence of energy (e.g. kinetic energy), and in other cases we usually only observe a change (e.g. chemical energy).

Here is a link to Lane's table illustrating the kind of thing we had in mind, except that instead of having separate columns for changes and presence, he put stuff related to presence in black and stuff related to changes in red.

Eleanor took up our suggestions in UE2, and at the end of the first day, she introduced a Keeley probe on models and presented the new columns for the forms table. Then they spent the entire second day negotiating what a model is.We knew that the term "model" would take some getting used to and expected there to be negotiation. But I don't think anyone, including Eleanor, realized just how much negotiation it would require.

To me, and to other scholars, it seemed like they were getting bogged down with the idea of a pedagogical model, rather than a mental model, as Hunter blogged about here.  The reason I had introduced the model column to the table was that when there was only an evidence column, they were bogged down talking about the evidence for it, rather than talking about it. Introducing the model column, rather than getting them talking about it, appeared to be getting them bogged down in talking about how to teach it. "Model" was the best word I could come up with for what I meant by it, but after seeing what it led to, I was afraid it was still not the right word. After the second day, I was convinced that my idea had completely flopped, and I should go back to being a researcher on the side and not make any more instructional suggestions ever again.

But I forgot about Eleanor's ability to help learners pull together what looks like a giant mess into a coherent structure, and this is exactly what she did by the end of the third day. I think the process of putting the mess back together started in the afternoon of the second day, when she split the model column into "pedagogical model" and "mental model" (or something like that), so they had a place to put the stuff they were talking about and could see that there was also something else they needed to talk about. They also watched a video of Feynman talking about imagining jiggling atoms. They spent pretty much the whole third day making sense of the Feynman video via both thought experiments and real experiments, and constructing and refining a very hard-won mental model of thermal energy. By the end of the third day, it seemed like everybody had a clear mental model of thermal energy, as well as an understanding of what a mental model is, and they were really happy about it.

The thing I didn't know before this week is that these teachers did not already have a mental model for thermal energy coming into the class. Knowing this, it makes perfect sense to me why this whole process took so long (two days)! For me, thermal energy is the quintessential example of why I need a separate column for evidence and model: because for thermal energy, more than for any other form of energy, the evidence and the model are completely separate in my mind. My evidence for thermal energy is a reading on a thermometer or the feeling of warmth, and my model for thermal energy is microscopic particles bouncing around. When people are confused about what goes in the model column, I want to say, "Just think about thermal energy." But they didn't have a model of thermal energy, so it makes sense that they would be confused about the whole exercise. It was worth spending two days to develop this model, because, as Eleanor said at lunch, "If you don't have a microscopic model of thermal energy, it's hard to really believe in energy conservation because it looks like energy just goes away."