Stamatis's group (Jim, Tim, Don, Bruce, and Derrick, who I just found out lives in the same tiny Central Washington town as my father-in-law) is thinking about a hand pushing a block across a horizontal frictionless surface. They have drawn their Energy Theater diagram and are supposed to be responding to Leslie's prompt, which is something like: "For each energy change on your diagram - a transfer or a transormation - what is the explanation for why that changed?" She explains that she wants a causal story or mechanistic explanation of why energy does what it does. For this reason, I'm calling the interactions that follow this prompt the "causation interactions."
This group begins by going over their ET diagram with one another. They have two content points: (1) Though their diagram shows thermal energy being produced, that's not from friction, it's from the biological processes in the hand. (Stamatis participated in their clarification of that.) (2) They are not sure whether they have properly represented the ratio of kinetic energies in the hand and the block, because they don't know the mass ratio. Their conversation about these two matters has a lull, and Stamatis speaks up. (This episode takes place at about 10:33am, 18 minutes into E2 110811 1015 Don.mp4, and is catalogued as E2 110811 1033 SV Isthatanexplanation.mov.)
Jim: Kinetic energy is also transforming parts of it to thermal energy
Stamatis: So I guess - I think -
Don: It's frictionless.
Jim: It's within the body.
Tim: Biological
Jim: We didn't - biological.
Tim: We burn calories
Jim: We didn't do the authentic thing with friction.
{Jim takes a drink.}
Stamatis: I guess what I'm thinking that, is that an explanation. So we have done,
Derrick: As opposed to accounting.
Stamatis: We've done the accounting; we can say that, right. We're looking at this - I'm trying to think about it, what, what would a, accounting, what would an explanation of this kind of account is, is that somebody goes and looks at the books of a company and says you know, this is what happened before, this is what happened later, this is what happened later, and so,
Derrick: You're asking us why we would expect (inaudible)?
Stamatis: Exactly. So we are saying, what might be an explanation that actually looks at that first arrow, what's that first arrow. What's the meaning of the second switch. I see a transfer there, and I see a transformation in the second one.
Derrick: What mediates the transfer?
Tim: I was thinking
Don: I can I can
Tim: here cause we still have units, this is transfer away so it shouldn't be
Don: Well if they're one system that means that they're
Jim: (inaudible) just started up.
Don: Yeah I'm good with that.
Tim: Down here there's some sound.
(I'm not at all sure what Don is "good with," but maybe that's because I can't hear Tim and Jim very well.)
From that first piece of the beginning, I feel like I can see why Stamatis entered into the conversation when he did: He understood them to be off topic on the ratio-of-kinetic-energies thing, and was trying to orient them to the question they're supposed to be considering. His orienting move is to affirm their diagram and then ask, "Is that an explanation," which I think he would agree is meant as a rhetorical question (we're all supposed to know that the answer is "no," and thus go on to construct an explanation). In some ways it seems like his prompt is well-received; Derrick immediately says "As opposed to an accounting," which Stamatis affirms. The rest of the group, though, doesn't give much indication that they understand what he's promoting, and the conversation goes back to the question of the ratio of kinetic energies.
After a short period of them talking about their own thing, Stamatis begins again (E2 110811 1037 SV WhatI'msayingisWhy.mov):
Stamatis: I guess what I'm saying is that I see seven units at every single one. And I also see some kind of sequence that tells me because I see less kinetic energy fewer people then more and more and more, I have managed to describe a block that is speeding up, and I have managed to keep seven actors gainfully at work. The quest- So I'm done with the first part. The second part is, how will I know - In the second picture I see that you have turned two of these actors into K's. Two of the C's into K's. And you kept then in the red circle.
Tim: (inaudible)
Stamatis: And you kept them in the red circle. So how could I explain that. And then what I'm saying is that in the next one, I see more K's than the previous one - number 3 I see more K's in the purple circle than in the purple circle in 4. And what i'm saying is that, why.
Don: The velocities
Tim: Actually there should be another K in here I think
Jim: Or should the K's, once it's moving should the K's in each of them be the same.
Don: That's what I was asking you.
At that point, as you can see in the video, Stamatis drags his chair into the center of the L formed by the group, I think because he feels he is failing to make his point and needs to really roll up his sleeves. Jessica and Kristy are working up a blog post about that part of the video so I know it will not go unrecognized.
In trying to understand what wasn't working about this beginning, I isolated the prompts I see Stamatis using:
- "Is that an explanation."
- "What might be an explanation that actually looks at that first arrow. What's the meaning of the second switch."
- "You turned two of the C's into K's and you kept them in the red circle; so how could I explain that."
- "I see more K's in this one than in the previous one, and what I'm saying is that, why."
These seem reasonable enough, but they don't work, in the sense that they do not succeed in getting the teachers to have the kind of conversation Stamatis is trying to get them to have. This unsuccessfulness is sticky; the ensuing conversation is quite long and for much of the time I get the same feeling, that Stamatis is trying to help the teachers focus on the prompted question and his efforts continue to be unfortunately ineffective. (I am pretty sure that he said this to me himself.) I think this justifies my sense that the beginning of this interaction is significant.
I can't decide whether to try to account for the non-working-ness, or just accept that this interaction didn't work for the participants and keep my eye out for interactions that work better. More as my thoughts develop.
Not a thought about the data, but about the philosophical issue of explanation: I think of explaining as a game, at which we succeed or fail, and for which we must know the rules. And by rules, I mean, explain in *what* terms for this round of the explanation game? Something, I believe, must play the role of an explanatory primitive in any game of explanation. So, when we challenge each other to answer "why?" I think this conversation will be productive only if we agree (implicitly or explicitly) on what will be the un-reduced or primitive terms of the explanation. And anything which we say does not explain might not explain on a lower (deeper) level but could explain on a higher (shallower) level. For example, I believe that accounting for the energy being here and there and saying where it goes and when and how we know IS AN EXPLANATION. But it is a higher (i.e., shallower) explanation than saying why the energy does what it does. So then you can dig deeper and play another round, with more primitive terms. I do not think it is correct to say that one level accounts but does not explain and the next level down explains. If that were true what would the verb be for happens next, at the next deeper level (because there is always another level)? The explanation is never absolutely finished but is pushed down.
ReplyDelete@Hunter: I agree with your general point. The task was, partially, about starting to develop a consensus about what we mean by explanation in energy transfers and transformations. The task given by Leslie was twofold: (1) to do ET, and (b) to explain the energy transfers and transformations. If the group believes that a and b are identical tasks, one would expect that they would say so. But they don't. Maybe the puzzlement and initial lull can be explained by their trying to understand the meaning of the two tasks.
ReplyDelete@Rachel: I would love for you to continue to "try to account for the non-working-ness."
@Rachel: I said "gainfully at work" as opposed to "painfully at work."
ReplyDelete@Stamatis: Fixed that, thank you. Makes a lot more sense that way...
ReplyDeleteyeah, but it's not as funny - i actually assumed that was a joke about how physical energy theater can get :)
ReplyDeleteI think of an "explanatory primitive" as a "bottom rung" of explanation that we usually don't have access to. (I think Newton 1 might be considered a request to say what "counts" as explanation is not in line with our intuitive e-prim that "things stop moving.")
ReplyDeleteOr maybe instead I mean that once we agree on explanation as causal story there are e-prims, and instead the thing to be agreed on is whether or not "explanation" means "causal story" (implicitly or explicitly)? But doesn't "explain" MEAN "causal story" ? Does to me.
I'm thinking of an earlier point this week when Bruce asked "what's e?" and I was trying to think of how to go about explaining the idea behind d(e^x)/dx = e^x and Stamatis explains how to calculate e. (1 + 1/1! + 1/2!...) -- but I don't think anyone thought that *explains* e.
Nice to see you chiming in Hunter. We miss you!
One possible interpretation of some of their responses to Stamatis is that they heard his "why" questions as attempts to probe the content of their thinking more deeply and help them arrive at a more correct physics answer. I can think of lots of examples in tutorials or even homework study sessions or office hours where an instructor says something like "why do you think that?" and means that they want a more detailed explanation of the choices that went into coming up with that answer. Not at all what Stamatis meant here, but that's how it seems like they heard it (with the possible exception of Derrick).
ReplyDeleteI like looking at the very beginning of the student / instructor interaction as well. I agree these initial interactions shed a lot of light on how the rest of an interaction will go. Here are my initial reactions after reading this post:
ReplyDelete1st episode: I get the feeling Stamatis interjected because he didn't think they were following the second part of Leslie's prompt. Unfortunately, his initial clarification of this prompt wasn't especially clear.
2nd episode: Stamatis was more explicit this time about what the group was successfully doing and what they were not yet doing, but for some reason they were still not understanding what Stamatis was getting at. It makes a lot of sense to me why Stamatis pulls in his chair at this point.
I see this almost as a cartoon in my head - The group was going down a different path than what was asked of them. Stamatis sees this and gives them a gentle turn in the intended direction. This doesn't work and the group turns around and keeps going as before. So, Stamatis picks them up and give them a slightly more directed push in the right direction. But, with surprising self correcting abilities, the group turns around and heads right back down that original path. Its actually pretty funny. I wonder what happened along the way, or what existing beliefs they brought with them, that gave them such determination!