How Far is Far Enough? Connecting Claims, Evidence, and Explanation
Case at a Glance
Teaching Practices:
Encouraging children to share their thinking and engage with each other’s claims and evidence
Using visual resources to support students’ thinking
Highlighting the importance of disagreement and engagement with one another’s ideas
Modeling uncertainty
About the Classroom: This is a second-grade classroom comprising monolingual children whose families indicate they speak English at home and multilingual children whose families indicate they speak Spanish or Portuguese at home. 30% of the students are designated as English Language Learners by the district.
Context: This case takes place within our second grade seed dispersal investigation, in a larger unit about plant needs and the places plants grow. Small groups have collected focal seeds and tested whether they travel by wind. They share their thinking during a Claims and Evidence Conversation.
Introduction
Children studying the “bushpod” share their thinking about whether their seed travels by wind during a whole-class Claims and Evidence Discussion. The case shows how the teacher structures a claim and evidence presentation and how she supports students to productively engage with uncertainty by highlighting the importance of disagreement and engagement with each other's ideas, modeling uncertainty, encouraging children to engage with each other’s evidence, and using visual resources to support students’ thinking.
We see how uncertainty emerges and how the teacher enacts these supports as children:
Share what they think now and why
Deepen claims and evidence
Explore mechanisms for how their seed travels by wind
Case Background
The focal seed for this case is likely a hibiscus seed; it is referred to throughout the case as the “bushpod.” The bushpod is made up of about 4 capsules that each contain 10-20 hairy seeds (Images 2 and 3). As you’ll see in the case, students seek to make sense of what kind of evidence matters for deciding whether the bushpod seeds travel by wind. Should they look at how far each inner seed traveled on its own or how far the the whole bushpod traveled?
When testing their seed to see if it traveled by wind, students placed their seed in front of a fan (Image 4), measured the distance the seed traveled on a piece of chart paper (Image 5), then recorded their preliminary claims and evidence in their notebooks (Images 6 &7).
Uncertainty in Action
The bushpod group shares their claims and evidence
The bushpod group stands in front of the room with a picture of their seed and its parent plant displayed on a slide behind them (Image 8). Their classmates sit on the rug. Lauren invites them to share, then records ideas on a claims, evidence, and explanations chart (Image 9) during the discussion. Students notice that the pods with seeds in them travel a different distance than the seeds alone.
Lauren: Alright, so my bushpod group. Do you think this seed is a wind traveler, is not a wind traveler, or are we not sure?
Luisa: Um, I think it was. Yes.
Lauren: You think yes. Felisa?
Felisa: I think no, because it didn’t really like go far.
Lauren: Okay. So, I’m hearing a yes. I’m hearing a no. You’re saying because it didn’t go that far. Luisa, why did you think yes?
Luisa: Because when you switched it to a little seed…it was kind of flying a little bit. So I would think yes. When, you put the big seed in the wind, it wasn’t really moving.
Lauren: Okay, gotcha. And then Felisa, could you respond to what Luisa was raising?
Felisa: So, I know what you’re saying…The big one didn’t really like fly. When it just went on the floor. It went like on the thingy, but not like on the seeds because the seed stayed a little bit more far… (Image 10)
Lauren: Can I help clarify what we mean by the big one and the small one? Because I know what you’re talking about. So, Luisa, Felisa, Grayson, and Serena, tell me if I’m correct and if I’m not. When you say the big one, are you talking about the outside pod?
Felisa & Serena agree.
Lauren: Okay, so the big one is the outside pod and the little one’s the actual seed inside. Correct?
Students nod their heads.
What we see …
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Luisa and Felisa make public the uncertainty involved in deciding what to count as evidence. Luisa thinks that the distance the pod traveled will provide the best information for deciding whether the seed is a wind traveler, while Felisa thinks the best source of evidence is the distance the inner seeds traveled.
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Lauren displays a slide showing the seed and its parent plant so everyone can access ideas about structure and function.
Lauren records the group’s ideas on chart paper.
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Lauren centers uncertainty, “Okay. So, I’m hearing a yes. I’m hearing a no. You’re saying because it didn’t go that far. Luisa, why did you think yes?”
Lauren supports students to engage with one another’s thinking and claims.
Lauren reinforces norms around uncertainty by recording “No” and “Not sure” in the claims section of the chart paper.
The bushpod group deepens their claims and evidence
Lauren asks a third group member, Grayson, to share what he thinks now and why. He introduces new ideas about how far the seed and the pod went. The class works with their chart showing seed travel distances to deepen their thinking about what counts as a seed traveling far.
Lauren: So, Grayson, what do you think? I’m hearing two different ideas come up.
Grayson: No. [It does not travel by wind.]
Lauren: Why?
Grayson: Because one just went down, and one went far.
Felisa: Yeah. (nodding).
Grayson: And one just went medium.
Eve: Grayson, can I hold up the sheet that you all measured the distance on just to remind myself how far it went?
Eve and Lauren hold up wind test results chart. (Image 12)
Eve: And this might be one we have some disagreement about. Maybe someone can say what they think. So, the triangles are the bushpods and when you’re talking about the big one, I’ll just say the pod, it didn't go far and the seeds on their own went medium…Grayson, can you come point to where the pod went and where the seed went?
Grayson points on the chart paper at where the pods landed. (Image 13)
Eve: So that’s the pod and then the seed went maybe here or here. And you’re saying that’s not very far? Luisa, is that what you agree with? That the seed went about here?
Luisa nods her head.
Eve: And you’re noticing the pod went here and the seed went farther than the pod. And Grayson’s saying yes, but he still doesn’t think that’s very far. That’s interesting.
What we see …
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Students disagree about whether the small seeds inside the pod traveled far enough for the bushpod to be considered a good wind traveler. Luisa thinks the seeds traveled far enough to make them good wind travelers, while Grayson thinks they did not.
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Eve and Lauren provide students with the chart paper to gesture with. They are asked to describe what they are taking as evidence to support their claim and guided through justifying their choice.
Lauren continues to fill out the anchor chart with all students’ ideas about evidence.
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Lauren centers uncertainty when she says she’s hearing two different ideas coming up.
Lauren and Eve reinforce norms about disagreeing in science.
Eve holds up the chart paper where students recorded distance and invites students to gesture to the chart paper and use it to help explain their thinking.
Eve revoices the evidence each student has used to support their claim, highlighting the disagreement.
Lauren writes all forms of evidence students share.
The classroom community considers mechanisms
Lauren asks students how they would explain why the seed is or isn’t a good wind traveler, inviting thinking about flight mechanisms. Building from prior work that had considered different parts that help seeds travel by wind (Image 14), children compare the pod to the seeds, begin to focus on the hairs on the seeds, and compare the bushpod seed (Image 16) to the milkweed seed (Image 17) to consider travel mechanisms further.
Lauren: I want to just have this group finish their thinking and then I’m going to call on all of you too. This is what we need in science. We need to have disagreements. If we always agreed all the time, we wouldn’t be able to learn anything new. I’m hearing a lot of evidence from what we saw. So how can we explain that based on what we know about that pod and about that seed. How could we explain why maybe it is or is not a wind traveler? I can make notes for both.
Felisa: So, I think it went further than the pod (Image 15). I think it was more like light, the seeds, because it’s little and when something’s little, they’re like really light. But the pod it wasn’t really flying. It was just moving and then it dropped off.
Maya: What Felisa kind of said, how things are light. I think the pod holding the seed doesn’t go far because it’s a very big thing. See how like humans can’t fly because they’re tall and heavy? It’s the same thing but like very lighter. It can’t fly.
Lauren: So you’re saying the pod didn’t go far because it’s so big? Because I’ve heard a lot of ideas about how the little seeds inside were little and light.
Maya: Yeah..But I think-because those seeds when I look inside, I realize there was hair around it, like little things. And so, I think that’s how they could fly.
Lauren: So, you’re proposing because of those little hairs that might help it be able to fly?
Maya nods
Lauren: What do you all think, since this is your seed?
Luisa and Felisa: Yeah
Lauren: I wonder later if the milkweed seed group and the bushpod group could do a comparison of your seeds and the hairs, because it’s interesting that they both have hairs but the milkweed seed went so much farther (Images 16 & 17).
Maya: Because they’re longer…and it’s bigger. You know how like a parachute is very big and they can move because like it’s very big.
What we see …
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Students still aren’t quite sure whether the seed flies, and are trying to think about mechanisms by which the seeds might fly.
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Lauren makes available an anchor chart where children had recorded structures that help different wind-traveling seeds to travel by wind.
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Lauren highlights the importance of disagreements in science and the importance of listening to one another.
Lauren orients toward an uncertainty students have identified around whether the small seeds can travel well by wind.
Lauren draws together ideas by highlighting comparisons students are making across seed structures and how the similarities and differences between the analogous structures may help or hinder the seed’s ability to travel by wind.
Reflections
This case study shows how orienting to students’ uncertainty and providing visual resources during a claims and evidence conversation supports students’ sensemaking. By reinforcing uncertainty in science, allowing children to choose and justify evidence, and supporting comparisons across seeds and investigations, teachers help students deepen their claims and evidence and make progress in understanding seed travel.
We encourage you to reflect on your teaching practices in light of your learning from this case:
Do children in my classroom have the agency to choose and interpret the evidence they use for their sensemaking? Are there ways to adapt my practice to provide children with more choice and support when generating their claims and evidence?
Do I—and how can I—make use of visual resources in the classroom for children to think and gesture with while making their thinking public?
What teacher moves from this case might I adapt for my own use toward establishing and maintaining a culture of productive uncertainty in my classroom?