Ambiguity in Evidence: “It Melted but It Didn’t Wanna Lose Its Shape”
Case at a Glance
Investigation: Heating & Cooling
Investigation Phase: Conducting Investigations, Claims & Evidence Conversation
Teaching Practices:
Expressing excitement for children’s discoveries
Making the purpose of work visible and a resource for sensemaking
Fostering children's multisensory engagement with resources
Orienting to an emergent uncertainty
Highlighting children’s puzzlement and the need for further investigation
About the Classroom: This is a second-grade classroom comprising sixteen students, with a mixture of monolingual English speakers and students whose families speak Spanish and Portuguese at home.
Context: This case takes place midway through the Heating and Cooling Investigation as children conduct the investigation, then work together to generate claims and evidence about whether chocolate chips remain solid or turn into a liquid after heat is applied.
Case Purpose
Lauren’s class is investigating whether materials, including chocolate chips, change state as they are heated. During the investigation, children observe tins of materials in small groups, exploring them through smelling, touching, and visually inspecting them. As children discuss their claims and evidence the next day, they realize that it’s not easy to apply the properties of “solid” and “liquid” that they read about earlier to the chocolate chips to make claims about whether they changed to a liquid when heated.
In this case, we see how ambiguity in evidence can motivate students to hone disciplinary practices such as argumentation and thinking about what counts as evidence as:
Children engage in a multisensory experience with materials as they conduct the investigation
Children share what they think now and why
Children deepen claims and evidence
Children maintain their interest in the ambiguity of the chocolate chips over multiple weeks
Case Background
At the beginning of the Heating and Cooling unit, children observed liquid cake batter change into a solid cake. They were curious how the change happened and whether any of the batter ingredients was responsible for this change. After exploring properties of materials , children revisited the phenomenon and developed their shared experience with it by reading a book about solids and liquids (Image 1). They drafted a chart of the properties of solids and liquids (Image 2).
They used this chart to classify materials including cake ingredients (e.g., butter, chocolate chips, eggs) into solids and liquids. They made predictions about whether the physical state of those materials would change when heated. They then conducted investigations to test their predictions. In this case, we focus on children’s exploration of chocolate chips, showing how they navigate uncertainty in evidence when debating whether heated chocolate chips (Image 3) are solid or liquid.
Uncertainty in Action
Lauren (the teacher) states the investigation question, “Do chocolate chips change into solid or liquid when heated?” Lauren and Eve (researcher) pass out tins of heated chocolate chips. In small groups, children explore the heated chocolate chips. Then, they write their observations, considering the state of the chocolate chips before and after heating.
Children engage in a multisensory experience with materials as they conduct the investigation
In small groups, children feel, smell, and stir chocolate chips with popsicle sticks debating whether heated chocolate chips are solid or liquid.
Eve: So is this melting or not melting? (Image 4)
Student: Not melting. It's just hot. It's hot.
Samuel: It looks like the outer shell of it turned a bit liquid, but it didn’t really turn into liquid. It’s shiny (Image 5).
Eve: It’s shinier, do you see that? Tatum, what do you notice?
Tatum: It’s shinier a little bit because it didn’t melt all the way
Sarah: Oh they melted
(Gabriel picks up the foil dish)
Eve: Whoa, is it hot or is it not…
Gabriel: It’s not hot…It’s Nutella! see! (pulling up popsicle with melted chocolate)
Tatum: Oh! it looks like Nutella (Image 6)
Student: I smelled chocolate creamy!
Gabriel: Ms. W, look! It’s liquid Ms. W! You just have to touch it! It’s liquid, Ms. W! You just have to touch it! (Image 7)
Eve: Wasn’t it so funny how it seemed solid and then Sarah thought to stir it?
Amber: I know what happened. It melted but it didn’t wanna lose its shape.
Gabriel: It was shiny! It was shiny!
Amber: I won’t believe it till I see it!
What we see …
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Children are uncertain what claim they can make about whether heated chocolate chips are liquid or solid.
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Multisensory engagement with materials is central to children’s sensemaking.
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Reminding children of the investigation question.
Providing access to resources, including multisensory engagement with materials (stirring, touching).
Expressing excitement for children’s discoveries, being responsive to the tools they want to use, and their interest in communicating with and convincing each other.
Children share what they think now and why
The next day, the teacher fosters a whole-group conversation about students’ claims and evidence. She restates the investigation question, asks children to share what they think now and why, and invites uncertainty. As Lauren facilitates this conversation, she makes resources available. She displays the picture of chocolate chips before heating on the board, has the properties of solids and liquids chart on the wall, and fills out a chart with children’s claims and evidence. As children claim whether chocolate chips are liquid or solid, they begin to uncover some ambiguity in their evidence.
What we see …
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Tatum begins to introduce uncertainty in evidence- if he focuses on the shape of the chocolate chips they are solid, but if he focuses on what happens when they were stirred, they appeared more liquid.
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Children can draw on their previous multisensory experience with the chocolate chips.
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Making the purpose of work visible by asking children to make and justify claims
Inviting and working with ideas
Probing children’s thinking to provide a resource for other students’ sensemaking.
Children deepen claims and evidence
As Lauren motivates children to deepen their understanding of claims and evidence, children argue that heated chocolate chips have properties of both liquids and solids.
Lauren: What do other people think about that? Did other people think that too?
Sarah: Sometimes I noticed the same as Terrell, but also it’s not ….it’s kind of a liquid. Because it was a solid. It was hot and it got shinier.
Lauren: So I'm hearing some evidence.
Sarah: It was in the same position that it was. But then what happened, it’s just because you touched it. But it’s also solid- it would stay its shape. It’s not really like water. So, I would say it was like a solid, both ways because it’s not spilling, but it is moveable. So I would say that the second way I think it’s still a solid…when it’s in shape, it stays its shape. Leave it out, it will stay its shape….
Lauren: So, Sarah you’re making the claim that it was a solid, then almost like a different type of solid?
Sarah: When I would touch it with a stick, it would like turn like into a solid-liquid.
Lauren: I’m just adding “only changed shape when touched” (Image 8,9)
Mikey: Well, when it was on the hot plate, you know how like, you took it off the hot plate, it was still in the shape of the chocolate chips? When you pushed- I think it turned into a liquid but stayed in its shape. Because, you know how it’s all gooey? I don’t think when you- I kind of think of like it’s a solid and a liquid.
Lauren: So became gooey and sticky (Writes on board). So Mikey, it almost makes me wonder if we, you know how we added some investigation ideas about the butter? It almost makes me wonder if we need to test trying to pour the hot chocolate chips? What do other people think about that?
Student: Yeah.
Lauren: Because would that give us more evidence of whether or not, because Mikey is bringing up a good point. It’s kind of like a solid and a liquid, and I’m hearing a lot of people agreeing with that, so maybe that’s an investigation we can do to gather more evidence?
Enzo: Yeah.
Lauren: And Ally, what were you and Leo discussing yesterday?
Ally: I was saying that, I was saying kind of the same thing that Mikey was saying that like it was kind of like both states. So I think it was bit more of a solid because on our properties of solids chart (Image 10), it says “keep, keep their shape unless you do something to them” and they did keep their shape until we touched them (Image 11).
Lauren: That’s– because- that’s like one of the very clear properties about the solids. That’s a great point and you’re using really clear evidence there Ally.
What we see..
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Children think about how to make sense of unexpected results as the chocolate chips don’t behave entirely like liquids (for example, not flowing like water).
Children consider what to use as evidence to support claims as they see that chocolate chips have some properties of liquids and some properties of solids. They debate which properties to use and what they mean.
Children consider whether they have enough evidence to support a claim.
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Children have already made and agreed on less complex claims, for example, that the ice and butter changed into a liquid, and supported these with evidence
Children can draw on their previous multisensory experience with chocolate chips
Access to resources like the properties of solids and liquids chart supports children’s navigation of evidence.
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Inviting multiple responses to the question and inviting children to respond to each other’s ideas before trying to do something with children’s ideas.
Highlighting children’s puzzlement and the need for further investigation.
Children engage in explanatory work
As children deepen their understanding of claims and evidence, they begin to consider why and how chocolate chips melt. Lauren works to understand children’s ideas and what they are making sense of.
Lauren turns back to Tatum, who has raised his hand.
Tatum: I think that if it would be important if it was actually still its shape because if it, if it was a little shiny, then it wouldn’t hold its shape…So, if there’s just normal chocolate chips, then if you put it in something hot, it will melt, but if it was like a little shiny it won’t, but it will kind of.
Lauren: So, are you saying there are different stages of when it melts? I want to make sure I’m understanding correctly. So you’re bringing up that it got shiny, are you thinking if it was only a little little bit shiny, it wouldn’t really have changed state?
Student: I think, I think––
Lauren: But hold on, I want to make sure I’m understanding Tatum and that all of us understand. But if it’s really shiny, that that’s when you’re able to stir it?
Tatum: Yeah.
Lauren: So there’s like a change that’s happening over time? (Image 12)
Tatum: Yeah.
Lauren: And do you think the amount of heat matters?
Tatum: It doesn’t really matter because you won’t really know how much heat got on it. You wouldn’t really know how much the heat was there because you wouldn’t know unless you set a timer, so like ten minutes. Then you would know.
Amber: I know the amount of heat matters because if you wanted to melt chocolate in a pot on the stove, and it cooks a little bit. It took a couple minutes. But …it got really hot and melted into a liquid. I knew it was a liquid because it poured and it didn’t keep its shape, it had no shape. We poured it into a cup and containers. I know that because that would happen…I know that the stove is hotter than the hot plate because there’s an actual fire in the stove and the hot plate doesn’t have fire (Image 13). And sometimes you boil that way with chocolate.
Lauren: Deanna, what are you thinking? Do you think it changed from a solid to a liquid or is it still a type of solid?
Deanna: It’s still a type of solid. Because in the middle- to feel it, it was like melting on the liquid but it was still keeping its shape a little.
Lauren: Does it get changed to a different type of solid? Does it change to a liquidy solid? What would you be comfortable with us recording?
Ally: I would say that it’s still kind of a solid…it just got really hot.
What we see..
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Tatum grapples with how the chocolate chips melt, connecting noticings such as their shininess and change in shape. He seems to be beginning to think about changes over time, but seems uncertain about how and why the chocolate chips might change into a liquid over time.
Deanna describes the material as still retaining some shape while also melting, indicating it might be in a transitional state. This duality creates uncertainty about whether it should be classified as a solid or a liquid.
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Access to resources (e.g., properties of solids and liquids chart) and previous multisensory experience.
Children draw from personal experiences
Children use analogies. Ally uses the analogy of lava being "gooey" to explain his perception of the physical state of chocolate chips.
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Orienting to an emergent uncertainty/question.
Working to understand a child’s idea and what they are making sense of.
Inviting multiple responses.
Validating children’s contributions through revoicing and summarizing their ideas.
Children maintain their interest in the ambiguity of the chocolate chips over several weeks
Over the rest of their experience testing materials and using what they have learned to explain how cake batter becomes a cake, children continue to be interested in the chocolate chips and their uncertainty about their state.
Deanna and Sarah make a poster summarizing what they had learned about how chocolate chips change when heated, and when heat is removed (Image 14). They draw detailed drawings and wrote descriptions of the chocolate chips before heating (Image 15) and after heating (Image 16), focusing on shape, stirring, and their remaining uncertainty about whether the chocolate chips were a liquid or a solid.
Other children made posters summarizing their final claims and evidence for other materials investigated, including butter, water, and eggs.
With these observations and claims in hand, children work to explain how the cake batter with the chocolate chips in it became a solid cake when heated.
Reflection
This case study highlights the essential role of productive uncertainty in fostering children's engagement in the scientific practice of argumentation and in refining evidence. By creating opportunities for students to engage in multisensory experiences, discuss observations, and navigate uncertainty in evidence, teachers empower students to assess and articulate their understanding of science ideas.
We encourage you to reflect on your teaching practices in light of your learning from this case:
How do I – and how can I – facilitate students' engagement with a variety of evidence, including integrating their personal experiences and sensory observations?
Do children in my classroom get to choose and interpret the evidence they use for their sensemaking in my classroom? How do I invite and support this process?
How do I respond when children don’t agree with each other at the end of an investigation? What strategies do I use to validate their ideas, acknowledge ambiguity, and consider what next steps (if any) to take?