Leveraging Student Expertise: Collective Sensemaking in Claims and Evidence Conversations
Case at a Glance
Investigation: Decomposition
Investigation Phase: Claims and Evidence Conversation
Teaching Practices:
Allowing students to investigate different questions
Implementing structures that help students engage with and value each other’s ideas and experiences
Inviting students to respond to each other’s claims and questions
Helping students connect claims, evidence, and explanations
Restating and stabilizing ideas students agree on
About the Classroom: This is a fifth-grade classroom comprising 16 students (8 boys and 8 girls). Students’ home languages include Spanish, English, Twi, and Portuguese. 25% of the students have diagnosed disabilities. The teacher, Lorin, has several years of experience teaching at this school, and it is her second year working with the design team as a teacher and co-designer.
Context: This case takes place at the end of the Decomposition Investigation as students present their final claims, evidence, and initial explanations. Students engage in collective sensemaking, working together to refine their understandings of their evidence and the mechanisms at play in their investigation results.
Introduction
This case illustrates a claim and evidence conversation, where students present and discuss findings from investigations. It shows how these conversations can involve naming uncertainty, understanding each other’s evidence, and beginning to explain findings by making connections across investigations.
After working in small groups to plan and conduct investigations of different questions about mold, Lorin’s students share their claims, evidence, and initial explanations with each other. Sabrina, Eva, and Lily claim that moldy tomatoes cause other materials to mold faster. They name and grapple with lingering uncertainty about why mold grows on different foods at different rates.
In this case, we see how Lorin supports students to make public and collectively engage with uncertainty as:
The presenters share their claim and evidence
Other students ask questions to understand the presenters’ investigation and evidence
Lorin supports students to engage in explaining a puzzling finding using evidence from their different investigations
Case Background
Sabrina, Eva, and Lily investigated the question, “Will a moldy tomato cause other things to decompose faster or spread mold to other things?” They set up two jars to investigate this question: both with different fresh food items, one with a fresh tomato [Jar 1] and one with a moldy tomato [Jar 2]. They observed the jars over a period of 20 days as their classmates conducted their own investigations (including examining the role of moisture, sweetness, and substrate in decomposition).
Over time, the strawberries in both jars started molding and other items in both jars began to mold, though Jar 2 always had more mold. The group was puzzled about why the mold from the strawberry in Jar 1, which became moldy quickly, didn’t spread to other items.
After conducting their investigations, each group made a set of slides sharing their setup, claims & evidence, research, and ideas about how they would change their investigations. Over two days, each class presented, took questions from classmates, and discussed their explanations. To prepare for the class presentations, Lorin discussed productive ways for students to give feedback and provided sentence starters to support community sensemaking.
Uncertainty in Action
We will take a close look at Sabrina, Eva, and Lily’s presentation and the Claims and Evidence conversation that followed.
Students share what they think now, why they think so, and their explanation.
As the presentations began, Lorin invited students to share what they thought now and why. Sabrina, Eva, and Lily projected their slides (Images 3- 15), reading from them and pointing out key ideas.
They claimed: “Moldy tomato makes things decompose faster. Things exposed to an already moldy environment will decompose faster than things that are not (Image 11).”
For their evidence: Students used their slides to show pictures of what was happening in their jars over the 20-day observation period. During their presentation, they described what they took as evidence from these observations, and shared the following explanation:
“We think that a moldy tomato will cause other things to decompose more quickly because we saw what happen in jar 2 that a moldy tomato made the other things decompose faster (Image 12).”
What we see…
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The group supports a claim with evidence and begins to propose an explanation (that mold is a spore that spreads to other materials easily and may need dampness to thrive). It’s not entirely clear from their presentation that they are grappling with uncertainty, though they propose a change to their investigation to focus on fewer materials and propose an interesting noticing- that the strawberry begins to mold first.
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During the presentation, students gesture toward their pictures and narrative observations when explaining their thinking.
The images and text remain available throughout the rest of the conversation as other students make sense of their claims and evidence.
Students respond to each other’s ideas and ask questions
Chase: Um, I agree with your claim because like all of your evidence that you gave makes me really think that um like a moldy tomato or anything else moldy will make other things more moldy because mold was already in the environment. Also, I’m pretty sure at my house there was one thing moldy once and then it made other things moldy.
May: Um, can you explain more about like your jar setup?
Lorin: (Switches slideshow back to the jar setup slide) Yeah, so can you guys explain what was in each jar? Like how you started from the beginning.
Sabrina: Oh, uh, can we go back to the next picture? (Lorin switches to the next slide) Yeah, uh, in the jars we had (pointing to the pictures) strawberry, grape and uh-
Lorin: So both jars had-
Lily: -the same thing-
Lorin: -strawberry, grape, carrot, and tomato.
Sabrina: But jar two had a moldy tomato.
Lorin: But jar two had a moldy tomato. Jar one had a non moldy tomato, okay. Any other questions on that, Maya? (Maya indicates no)
Rowan: Which fruit, which fruit did the tomato spread its mold to first?
Sabrina: (Pointing at a picture on the slide) The strawberry.
What we see…
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Often when groups present they don’t provide all the information others need to make sense of their claims and evidence. We see May making sure she understands the setup of the investigation, which is important for making sense of the evidence, but not made explicit in the slides visible at that moment.
Further, Rowan’s question provides an opportunity to see new possible factors that might matter.
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Because the slides are available as a resource, Sabrina can go back to the investigation setup to show May.
We see the result of the classroom culture Lorin has worked hard to cultivate throughout the year as students indicate their agreement and ask questions driven by interest.
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Lorin thinks along with students, clarifying, revoicing, and asking students if they are satisfied or are wondering more after they have posed a question.
Lorin orients to the group’s uncertainty around mechanisms that might explain their observations
Lorin: I have a question that might kind of lead off of what Rowan just asked, where you said something you would like to change. She switches slide to that slide.
You said rather than putting all of those things in the jars, you would put just a strawberry and then the tomato and a moldy one and a non moldy one. Why would you choose to make that as your change? Why did you guys decide that you would want to take out those other fruits and vegetables?
Sabrina: Because we saw what happened in our jar, the moldy tomato spread mold to the strawberry more than other things because the strawberry was soft.
Lorin: Okay, so you think that the strawberry is soft so that got mold first so you’d like to just focus on the strawberries themselves? Interesting. What do we think about that?
What we see…
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Sabrina may be considering how to develop an informative comparison as she considers not using the vegetables in the investigation and only using strawberries.
She expresses the group’s uncertainty regarding why the tomato spread mold to the strawberry more than other things. Sabrina also provides a guess about a factor that might matter for why mold appeared to grow first and fastest on the strawberry: the strawberry’s softness. However, the group has not yet proposed a mechanism by which this factor might lead to faster or more mold growth.
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Lorin connects Rowan's question to the presenters' proposed change to their investigation. This opens up opportunities for the presenters to make public the uncertainties they are grappling with.
Lorin moves from Sabrina’s response to an invitation for the class to engage with the uncertainty, asking “So what do we think about that?”
Lorin supports students to engage in explanatory work by making connections across their investigations
Lorin: I heard some other conversation in other groups about fruits and if they’re soft or not and that causing mold. What do we think about that? Malcom and Reggie, what do we think about the fact that the strawberry is soft and maybe that’s what’s causing it to mold?
Reggie: Because it was injured. Mold goes into, uh, fruits that are injured cause that’s easier to go into fruits that are injured.
Lorin: So some research that Reggie and Malcom are going to talk about, talk about fruits and vegetables that get injured more are more likely to get fungi and molds invasion. What else, Alexis?
Alexis: What I think is that mold goes into like sweeter and softer like fruits instead of like injured fruits so it would kind of make sense that the strawberry was moldy because the strawberries like more like sugary and then, it’s like more softer than like the other things you have in that jar (Other hands go up - see Image 20).
Lorin: So now also thinking about sugar content.
Rowan: Like Lily said, um,...how one piece was similar to Evelyn’s, May’s, and Salma’s, how they both were talking about moisture. This is, this one might relate to Malcom and Reggie’s because the strawberries are sweet fruit and in their jar, the strawberry molded a lot faster than the carrot.
Catherine: Um, more sweeter fruits because sweeter fruits would provide more energy for the mold?
Lorin: So some additional explanations. So you guys were talking about how soft the strawberry was, it seems like some people might agree with that, but some people are also adding on the fact that the strawberry was probably sweeter than the other things in the jar. So maybe that was also causing more mold.
20. Students engage with each other’s ideas
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Students also grapple with how to move from individual cases to comparisons across investigations. The strawberry in the presenting group’s investigation became moldy almost immediately in both jars, but even after the strawberry in Jar 1 (with the fresh tomato) had molded, the other food items took a while to mold. Why is it easier for mold to grow on some things than on others? What factors might determine whether a mold spore can travel to, land, and begin to grow on a food item?
Students suggest multiple possible factors (softness, high sugar content, moisture) that matter for the ability of mold to grow on a food item and mechanisms that might explain why those factors matter (softness makes it easier to for mold to get in; high sugar content provides more energy for mold to grow). Their responses draw on and help them develop understandings of mold as an organism that has a life cycle, including traveling to and beginning to grow on a new source of energy and nutrients.
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Lorin invites multiple responses to the group’s uncertainty.
Lorin positions other students, including students that have typically been less successful academically, as having expertise to contribute, based on her knowledge of their thinking.
Lorin values and connects responses without needing to provide the explanation- she supports children’s work to explain rather than focusing on one correct explanation (and in this case, it is very possible that all of these factors contribute).
Reflection
This case highlights the essential role of productive uncertainty in fostering children's engagement in the scientific practice of supporting arguments with evidence and refining claims and explanations. By creating opportunities for students to make their thinking visible to others, discuss observations, and navigate uncertainty in evidence, teachers empower students to assess evidence and engage in explanation. Students make progress on understanding a phenomenon, applying and deepening ideas about mold as an organism that must travel, get into an item, and meet its needs as they explain what they are seeing.
We encourage you to reflect on your teaching practices in light of your learning from this case:
Are there investigations I teach where students might study different aspects of a phenomenon or focus on different materials to generate expertise, establish a need to question each other, and provide opportunities to combine their learning?
When students present and engage with each other’s claims and evidence in my room, what support do I provide beforehand and in the moment for students to engage in considering and evaluating investigation setups, evidence, and potential explanations?
