What directly preceded this conversation: This episode is preceded by Lane posing a thought experiment. The class had considered the situation of placing an ice pack in a water bath. Now Lane asked them to considered what it would be like if the ice pack was placed in the canal outside. If they had a thermometer in the canal and recorded no change in temperature, would they have evidence that heat energy had been transferred to it?
UE1 120628 1202 T5 NOS 1045
Valerie: On one hand, you are arguing that we should base
what we’re doing on knowledge that we’re constructing. And to argue that there
was a transfer of thermal energy, which we all know there was, even if there’s
no evidence for it, to use our prior knowledge, to affect, to interpret what
we’re seeing. So, we have to think about that. I mean, which one are we trying
to do?
Lane: Do we, in that case, do have evidence?
Valerie: We don’t have any evidence.
[Several learners jump in.]
Valerie: But we could come up with a completely other
scenario for it, for why the ice melts. There’s like no evidence that there’s
thermal energy coming from it. Only prior knowledge that there’s thermal energy
coming from it.
Kristy: Well, I think the ice pack melting is evidence that [Several people overlap speech.]
Jeannie: Canal water isn’t room-
Sean?: [inaudible] controlled
experiment, because here you have a limited amount of stuff and there you have
a huge amount of stuff. So you can’t say that one thing affected the other,
without using a smaller scale. The bath water actually got colder so you could
see the energy changing. [Inaudible].
Lane: But I think Kristy’s saying,
what I hear Kristy saying is that there’s evidence of a transfer of energy into
the ice pack, even out there, because its temperature changed in a [inaudible]
way. That is evidence of transfer into the ice pack, but it’s not evidence of
where it came from.
Valerie: Yeah, but there’s a lot of
inferring there and basing it on prior knowledge. Because just imagine someone
who know nothing about thermal energy, what would they think of the ice pack
melting? I mean, if you say there’s a transfer of energy because [inaudible].
You’re just using what you know to answer a question.
I have two unrelated thoughts about this episode. First, Valerie seems to be struggling with what kind of information you can use what making a scientific argument. It's relatively straightforward to tell learners we need to base our claims on evidence, but here it looks like that is hard to put into practice. While we base our claims on things we can observe, we have to use deductions and reasoning to make the connection between evidence and claims. When you've also adding reasoning to the process, then it seems kind of silly (from Valerie's point of view) to ignore previous knowledge gained from the recent experiment: the temperature of the water in the bath goes down, so our model tells us it's losing heat energy to the ice pack. I sympathize with Valerie, because she's taking a conclusion based on evidence and extending it to the new thought experiment: if we conclude the ice pack is gaining thermal energy and it's in the canal, it seems like we're using reasoning to say the likely place the thermal energy comes from is the canal.
My second, shorter, thought is about the researcher characterization of this conversation. Ben and I both heard this conversation and labeled it "about the nature of science." But it occurs to me that it's really about what rules they're following in this discussion and in this class. It would only be about the nature of science if the learners see what they're doing in this discussion and in this class as science. (And I'm sure many NOS researchers have already had that thought, but it's new to me.)
I would love to converse about Valerie's idea of not using previous knowledge gained from a recent experiment. Is that something she decided? Are you concluding that she only used evidence to connect to new concept and not reasoning?
ReplyDeleteAbby and I have been looking at episodes in which learners infer the existence of an imperceptible form of energy from conservation of energy. We have been using these episodes as cases of students using sophisticated reasoning. This episode is another case of exactly what we've been looking at. But here, Valerie dismisses exactly the thing I've been using as evidence of sophisticated reasoning (inference), as being inadequate and not as good as direct observation: "but there’s a lot of inferring there and basing it on prior knowledge... You’re just using what you know to answer a question."
ReplyDeleteI think people are interpreting this episode differently than me. It seems that we all agree that Valerie is dismissing/feels dismissive about the idea of using prior knowledge. However, I interpreted this clip as Valerie feeling that *science* (or the instructors) are telling her that she is not allowed to use prior knowledge, even when it's obviously applicable. I saw her as frustrated because she thinks it would be silly to ignore the knowledge they developed from the previous experiment.If this is the case, then that is a message that I don't want her to receive about science.
ReplyDeleteIf anyone wants to watch this again and tell me how they interpret it, I'd appreciate it. I've looked at the video that precedes this, and it doesn't shed light on Valerie's perspective.
I watched it, and I wanted to know _who_ Valerie was referring to when she says "you" in the first line of the transcript. I share your interpretation, Renee Michelle -- that she feels that the only way to answer the question is to extend the bathtub example (although I agree with Kristy that the ice pack melting is evidence embedded in the canal example) -- and she thinks the unnamed "you" has told her she can't do that.
DeleteRM, do you recall who she's directing this statement at?
I watched it again, and I don't think there's enough evidence either way for me to distinguish between the two interpretations. Either way, what stands out to me is that she seems to view "inferring" as unscientific and in the same category as "prior knowledge". This is surprising to me because I view inference as the highest form of scientific reasoning, and quite distinct from what I think she means by "prior knowledge", which is just believing something because someone told you.
ReplyDelete