Figure 3. Students’ participation in modeling activity during the book-reading phase
indoor tests of seed travel represented aspects of the backyard setting. They also began to think how they might make claims based on what they saw indoors, both in relation to the model system tests and the seeds’ properties. For example, as they worked with the fan, they were asked to consider how they could measure the success of a seed traveling by wind, then settled on using a count of floor tiles to record and compare distances.
Increasingly, seeds were regarded as collections of properties that supported a particular mode of travel; students developed theories such as:
“I would say that if other plants had like cotton or fuzzy stuff on it, it will float.”
“I look at the stuff that’s on it and I look at the shape and if it has spiky stuff I can tell [it travels by sticking] or if it’s just a smooth seed like an apple seed I can tell it won’t stick because it doesn’t have anything to stick to.”
In addition, students considered the fit between their evidence in the model system tests and what might actually happen outside. Several students used features of the outdoors to make their argument plausible. Anthony argued that there are animals and people in the backyard. Tyree chose air travel over water for his seed because he thought it was unlikely that there were floods that generated enough water for water travel and then challenged Daria on the same point when she presented her argument to the class.
This phase involved a significant shift in discourse, for both teachers and students.
Conversation moved between teachers a) arranging for students to see something and positioning them as noticers and explainers and b) positioning students as claim-makers who themselves need to select, arrange, and highlight relevant aspects of the situation. The first role, enacted initially during the book reading, was more firmly established in the classroom and appeared easier for the teacher to orchestrate. In the second role, students needed to decide what to see, what and how to measure, what to relate, and then organize those ideas to make a claim. For
example, the first positioning was enacted as the teacher took two seeds (an acorn seed and milkweed), dropping them from the same height and blowing on them and asking students what they noticed about how the seeds fell, then asked which would travel farther in wind. In contrast, in the second positioning, students were asked to look at the milkweed and say whether or not they thought it was a seed that animals would bury to eat later, then justify their claim. As students became more adept at the latter forms of participation, what they saw and how they saw it were transformed. Seeds were partitioned into features that could promote particular models of travel and the backyard itself became populated with newly significant entities, e.g., wind that had the potential to blow seeds, animals that might carry them, and water that could take them to new places.
Example episode: Anthony’s claims about sticking (December 9). Anthony’s presentation in a “research meeting” demonstrates how students, models, and concepts were positioned in relation to each other and how teachers supported students to make and consider claims embedded in modeling activity. The research meeting (Lehrer et al., 2008) is a
participation structure in which students present their claims, call on other participants to ask questions, and then ask for suggestions. In this first, simplified, use of this structure, students were asked to listen, to be ready to restate presenters’ arguments and evidence, and to ask questions. From the backyard, Anthony had procured a small seed in a slightly larger seedcase with two spikes sticking out the end of it. He claimed that this seed traveled by sticking to animals.
1. Anthony: I think my seeds traveled best by clothing, fur, and feathers because animals walk back there and classes because it is on school property.
2. Mrs. W: OK, well keep going. What else did you write in there about how the seeds travel? What did you decide about how the seeds travel?
3. Anthony: That’s it.
4. Mrs. W: Just say what you told Ms. W. earlier.
5. Anthony: I think...
6. Mrs. W: Look in your notes. How did you say that seed traveled?
7. Anthony: I thought it traveled by wind and water first. Then I changed my mind, because when I was at the wind center, it only flew two blocks [a distance of two tiles on the floor]. When I was at the water center, Ms. W., she moved the water and it didn't float around that much. So then I picked clothing, fur, and feathers because lots of people and animals walk around back there. And it sticks to their clothing, and it, like, sticks to something’s fur.
Anthony’s initial argument (Line 1) is constructed as a plausible story of dispersal based on features of the backyard. Mrs. W. encourages him to return to his notes and recall his earlier conversation with her. At that point he mentions several tests. However, he mentions neither his test of seed sticking, nor the seed’s structure. Because Mrs. W. has worked with Anthony, she knows that there is a seed inside the seedcase that he is showing the class. She leads him to describe what was in there and why he opened it up to see it. EM takes out a seed and sets it by the other on the FlexCam. She then invites other students to participate.
8. EM: Who can restate Anthony's argument?
9. Mrs. W: I think Kelly says she's ready.
10. EM: Kelly, go ahead. How does Anthony think the seed mainly travels?
11. Kelly: By umm, clothing and feathers.
12. EM: Clothing and feathers. Anthony, is that what you were trying to tell everyone that you think is the way it mostly travels?
13. Kelly: And he said mostly.
14. Anthony: No. I was trying to say clothing, fur, and feathers
15. EM: clothing, fur, and feathers. Does that make sense? (to Kelly) Is that what you=
16. Kelly: =I forgot fur.
17. EM: And who can restate Anthony's evidence? Why did he think the seed traveled that way? What made him think that?
18. Mrs. W: Shawanda?
19. Shawanda: Because… (2 sec)
20. EM: I know it might be hard to say all of his reasons because he gave us a lot of rich information. Can you try one of the reasons he thinks?
21. Shawanda: Because of the hairy stuff. (EM checks to see if others hear, Shawanda repeats more loudly.)
22. EM: Was that one of your reasons, Anthony? (He nods.) Could you maybe call on someone else who can tell you another of your reasons?
23. Anthony: Colby.
24. Colby: Probably because... because he did all those tests with Miss Eve, Dr. Rich, and
Mrs. W. but-with the wind and it probably was a successful test, but on ground it probably didn't work, and so the water with Mrs. W., when she was spinning it around it didn't move a lot, right?
25. (Anthony nods.)
26. EM: Anthony, that's correct? He told you that back correctly?
27. Anthony: Umm hmm.
28. EM: Was there anything else, Anthony, that you think kids have not said, that's what you were also thinking was a piece of evidence?
29. Anthony: Mmm hmm. The little sticks on it, because I put it on my shirt and it was sticking by those little sticks.
Anthony is framed as having a claim (about sticking) and evidence. Note how much evidence he shares over the course of his presentation: plausible features of the backyard (animals and people), that the seed did not travel very far in the wind or water centers used to model outdoor processes, that it sticks to his clothes, and that it has “little sticks” on it. However, it takes significant work from the teachers and from other students to make his argument emerge and become subject to questioning and/or critique. Mrs. W asks him to recount what she and he talked about and reminds him to use his journal as a source of his argument (Lines 4 and 6). EM tries to make his ideas visible to other students by removing the seed from the casing, projecting it, and asking others to restate his argument. She asks Anthony to corroborate the summaries of his argument and evidence, framing him as their maker and providing an opportunity for him to become aware of how his statements are heard by his audience. As Anthony hears other students revoice his partial statements about aspects of the seeds and the model tests, he is able to add two pieces of evidence that he had not privileged in his initial talk: the sticks on the seed and the fact that he put the seed on his shirt and it stuck to his shirt (Line 29). The social work around the frame of the modeling activity (magnification, claim writing and sharing, and the use of model tests of seed dispersal) supports Anthony in communicating what he knows and how he knows it, coalescing his ideas and experiences into a coherent claim-evidence pairing.
Students are next encouraged to ask questions.
30. Tyree: So you said... is it like that the littlest one is the seed, and maybe the biggest one...the biggest one is the seed case?
31. Anthony: Yes (nods).
32. Tyree: So I'm saying, did you stick the seed case on you, or did you stick the regular seed?
33. Anthony: The seedcase, because the seed was still inside of it, and then after that, I took it off my shirt and opened it.
34. Tyree: So did you stick the seed on your shirt?
35. Anthony: (1 sec) No.
...
36. Julie: How long did the uhh...the seed stick on your shirt?
37. Anthony: A long time.
38. EM: Julie, what made you ask that question?
39. Julie: Because umm... a lot of the seeds don't stick that long, that's what I was wondering.
40. EM: And what would it tell you if it did not stick very long?
41. Julie: It would probably tell you… because maybe the hairs come... you can see like tiny hairs on your shirt, maybe that's how the seeds stick to your shirt
probably.
In these lines, students are involved, albeit in simple ways, in attempting to understand and critique the models or investigations that others have used to make claims. Tyree begins to grapple with a potentially important distinction—the seed and the seedcase (Lines 30-35). Julie has begun to notice, perhaps from her experience testing her seed, that some seeds stick to
material for just a short time. This remark constitutes a movement toward the need for a measure, a push past a dichotomous variable (sticking vs. not sticking) to duration of sticking time. This excerpt illustrates a new opportunity in the classroom: the making and critiquing of claims leads to emergent possibilities for students to realize their own role in creating model systems and designing measures of those systems that allow them to make claims that stand up in public.
Summary: the relation of modeling and concept. In this phase of activity, students participated more fully in all aspects of modeling activity (Figure 4), leading to new
opportunities for conceptual development. Even with basic modes of amplifying and testing
provided to (rather than invented by) them, students had to figure out how to see and what would count as showing something to another person. This work made new conceptual features of both the seeds and the outdoors apparent. For instance, as students magnified seeds and wrote
arguments, seed structures and the function of those structures became increasingly evident. In addition, as they presented their arguments, social activity focused on communicating and understanding how individuals made models, using the model system to develop claims, and understanding entailments provided an opportunity for developing conceptual meanings. For instance, students were pushed to differentiate seeds from seed casings as other students sought to understand how they tested their seeds, as in Tyree’s question to Anthony. In addition, they began to further differentiate outdoors conditions as they sought to apply their models to explain whether their seed would travel the same way outdoors as it had indoors.
During this phase students did not necessarily learn a new reproduction concept in the traditional sense. They had already listed all the ways that seeds travel, and no new methods of seed travel were proposed during the investigations. Rather than learning (in the sense of receiving) knowledge, they had to understand how to make shared knowledge, and in doing so appeared to further differentiate the idea of seed travel and its entailments in the backyard.
Modeling brought into relief the relations between modes of travel, features of the seed, and features of the environment. As a result, both seeds and the outdoors became further
differentiated: seeds into sets of structures (seed cases, sticks, fuzz, air), the outdoors into new partitions (amount of rain, windiness, presence of other organisms like animals and people) that mattered for the question at hand: an understanding of how the seeds traveled.
Figure 4. Students’ participation in modeling activity during the seed claim-making phase