Claims, Evidence, and Reasoning in Science Education PDF

Photograph courtesy of the author Demystifying data during a unit on simple machines By Katherine L. McNeill and Dean M. Martin fifth-grade class is in the middle of a...

Photograph courtesy of the author Demystifying data during a unit on simple machines By Katherine L. McNeill and Dean M. Martin fifth-grade class is in the middle of a unit on simple and writing. Dr. McNeill collaborated with Mr. Martin machines. The teacher, Mr. Martin, asks his class, to analyze students’ writing and videotapes of classroom “Does a lever make work easier?” One student discussions to identify student strengths and weaknesses responds, “I think it makes work easier,” another and to develop future lessons to meet their needs. Mr. student disagrees stating, “I think it depends.” Mr. Mar- Martin then tested those strategies in his two fifth-grade tin then responds, “Each of you has just stated a claim. By classrooms. In this article, we describe the strategies we the end of our investigations today you will be able to pro- used to help students demystify data and share their re- vide evidence to prove which claim is actually correct.” sults. We use examples from a unit on simple machines to illustrate the process, but the strategies and framework Although students are enthusiastic when engaging in can be used in any science content area. hands-on investigations, they can find it challenging to make sense of their data and to create explanations us- ing evidence from their investigations. We spent a year The Framework designing and testing strategies in Mr. Martin’s science National Science Education Standards (NRC 1996) and classroom to better assist his elementary students in con- reform documents (Michaels, Shouse, and Schweingruber structing and justifying their claims in both science talk 2008) include a focus on having students use evidence, 52 Science and Children construct explanations, and engage in argumentation. These meaning-making experiences, whether during Figure 1. classroom discussion or while writing, are essential for effective science instruction. To support students in Visual representations of claim, communicating their explanations and engaging in ar- evidence, and reasoning. gumentation, we developed a framework that simplifies these complex practices for students (McNeill and Kra- jcik 2011). At the elementary level, we typically introduce the framework as consisting of three components: claim, evidence, and reasoning. The claim is a statement that answers a question or problem. Evidence is scientific data that supports the claim. The evidence can come from investigations students engage in firsthand or from research conducted online or in books that provide data. Last, reasoning provides a justification for why or how the evidence supports the claim. The reasoning often includes scientific principles or science ideas that students apply to make sense of the data. As students gain more experience and expertise with the framework, we then introduce a fourth component— rebuttal. The rebuttal describes an alternative claim and provides counterevidence and counter reasoning for why the alternative claim is not appropriate. Typically, we have not introduced the term rebuttal until middle school, though elementary students can debate different claims and evidence in classroom discussions. The claim, evidence, and reasoning framework can support students in productive classroom discussions and science writing because it provides them with a structure to communicate and justify their ideas. claims all the time in their everyday lives. In science class, we often make claims when we answer questions Introducing the Framework in our investigations. After discussing the term claim, When first introducing the claim, evidence, and rea- Mr. Martin wrote the definition on a poster to provide a soning framework, Mr. Martin wanted to make the vo- visual reminder for all his students (Figure 1). cabulary accessible to his fifth graders, so he connected Then, he asked Clara for proof that she had a great the language to his students’ prior ideas and everyday weekend. She responded, “I played with my cousins, we experiences. In the introductory lesson, Mr. Martin had a party, and we ate ice cream.” Mr. Martin then ex- began by asking whether anyone had ever heard of the plained that the proof that she just shared was evidence. words claim, evidence, and reasoning before. One stu- Evidence is data that helps support your claim that you dent responded, “I saw a TV show that had police in it had a good weekend. After adding the definition of evi- and they were looking for evidence.” Another student dence to the poster, the class discussed other examples said, “I know a reason for something like, the reason of evidence that would support the claim that they had we come to school is to learn.” Mr. Martin encouraged a great weekend. multiple students to share their ideas to develop a better Last, Mr. Martin discussed the term reasoning by understanding of their prior ideas about these terms. stating that reasoning helps you explain why or how Next, Mr. Martin posed a simple question to con- your evidence supports your claim. He asked his class nect to their everyday experiences. He asked the class, to brainstorm a list of things that answered the question: “How was your weekend?” Clara replied, “I had a great What does it mean to have a great weekend? The class weekend.” Mr. Martin followed up by responding, “You discussed that having a great weekend means that you did? Well you know something else you just did? You just had fun and that you enjoyed yourself. Certain activities made a claim.” He then went on to explain to his students are often evidence that you had fun—like playing, a party, that a claim is simply an answer to a question. They make and ice cream—but not always. For example, you could April/May 2011 53  day examples help students see that they already Figure 2. know how to construct a strong argument and that they can use similar strategies in science. Antonio’s written scientific argument. Designing Classroom Supports After introducing claim, evidence, and reason- ing in this initial lesson, Mr. Martin used the framework throughout the school year to sup- port his students in making sense of and ex- plaining the data they collected in their inquiry investigations, including with a unit on simple machines. The fifth graders completed two lever investi- gations as part of the Full Option Science System (FOSS) module Levers and Pulleys (Lawrence Hall of Science 2005). In the investigations, Mr. Martin’s students collected data around how the positions of the load and effort, relative to the fulcrum, affect the amount of effort required to move an object. Specifically, the investigations focused on the idea that a lever can make work feel easier, because a lever can reduce the amount of force required to move a load. The investiga- tions did not focus on the idea that a lever may also reduce the required distance, though this would also be considered a mechanical advantage. In Lever Experiment A, the position of the load stayed constant and the students changed the position of the effort. In Lever Experiment B, the position of the effort stayed constant and the students changed the position of the load. In both eat too much ice cream and your stomach could hurt. So investigations, as students manipulated the positions of the reasoning needs to explain why or how the evidence the effort and load, they recorded the amount of effort supports the claim that you had a great weekend. Mr. required to move the load. Martin added the definition of reasoning to the class To help students make sense of and share the results poster. He explained to his students that they would be from their lever investigations, we developed the stu- using these three components—claim, evidence, and dent sheet in Figure 2. Specifically, we asked students reasoning—when they needed to answer a question or to write an argument that answers the question: Does explain the results from their investigations. They would a lever make work easier? The student sheet includes need to support the claims they made in science class, just writing prompts with claim, evidence, and reasoning to like they had supported the claim that Clara had a great remind the fifth graders that they need to include these weekend. The evidence would look different because it three components when they write a scientific argu- would come from their observations and measurements ment. Students needed help learning how to apply the from their science investigations. The reasoning would framework to different science ideas (e.g., biodiversity look different because it would include science ideas. But vs. simple machines). Consequently, we included in the their arguments would have the same structure. writing prompts descriptions of what we were looking In this case, the question of “How was your weekend?” for in this specific investigation. For example, under was used to introduce the framework. Other teachers we Evidence the student sheet states, “Provide scientific have worked with have used different everyday examples data to support your claim. Use evidence from your in- such as: Who is the best basketball player? How long vestigation including the position of the fulcrum and the should recess be at our school? What is the most popular amount of force required to lift the load.” The first sentence song? The examples the teachers used depended on the provides a general definition of evidence. The portion interests and backgrounds of their students. These every- that is in italics specifies what students should be using 54 Science and Children  Claims, Evidence, and Reasoning as data from their specific lever investigations. Includ- in the writing. Antonio provided the correct claim that ing both the general and investigation-specific support a lever can make work feel easier but that it depends, so in the writing prompts helped the fifth graders write the he received a 2 (on a scale of 0–2) for his claim. In terms strongest scientific arguments by both reminding them of his evidence, he provided general statements about of the framework and helping them see how to apply it what occurred in his investigation, but he did not provide to the specific investigation. specific data or numbers. Consequently, he received a 1 (on a scale of 0–3) for evidence. This helped us under- stand that although he knew evidence was “Data from Using Rubrics Experiment A or B,” Antonio did not understand that We developed a rubric to help us identify the strengths he should use specific numbers. For reasoning we gave and weaknesses in the fifth graders’ writing about the him a 2 (on a scale of 0–3)for providing a generalization lever investigations (see NSTA Connection). For this about levers stating, “The position of the effort and load specific example, we used the rubric to analyze the stu- on the lever change the amount of energy needed to lift dent writing to inform future instruction. In other les- the lever,” which articulates why he came up with the sons, Mr. Martin provided similar rubrics to his stu- claim that it depends. Yet he did not talk about the idea dents to support them in evaluating their own writing of “work,” which we had specifically included in the and to help them revise their writing to provide stron- question and prompt to encourage students to talk about ger justifications for their claims. We used the claim, this scientific idea. Few students in the class actually evidence, and reasoning framework to develop the three discussed the idea of work, which suggested to us that categories of the rubric and the content from the two they needed more support around including this science lever investigations to develop the levels for each cat- idea in their writing. Figure 3 includes an example from egory (McNeill and Krajcik 2008a). another student in the class, Hannah, who has different Using this rubric to examine Antonio’s writing (Fig- strengths and weaknesses. She also made a correct claim, ure 2) helped us identify the strengths and weaknesses but the evidence and reasoning she provides are differ- ent. We gave her a 3 for evidence, because she did include specific data (e.g., when we had the Figure 3. effort on 2.5 it was 9.4 N) to support her claim. Hannah’s written scientific argument. We only gave her a 1 for reasoning, because she did not provide any generalization about levers or bring in the science idea of work. The examples of student writing from these two students illustrate the challenges some fifth-grade students had with writing scientific arguments during the middle of the school year. Initially, introducing the framework helped the students be better able to provide a claim that specifically addressed the question and included some justification for why they came up with the claim. Yet they continued to struggle with including specific data as evidence to support their claim and providing reasoning to explain why their evidence supported their claim. Using rubrics helped us identify these challenges, provide students with feedback, and modify instruction to meet their needs. For example, based on the student challenges using evidence during the lever investigations, Mr. Martin facilitated class discussions dur- ing which students shared their evidence and had peers agree or challenge the quality of the evidence. This led to the class discussing and students recognizing the importance of includ- ing specific data (measurements) and specific April/May 2011 55 Claims, Evidence, and Reasoning vocabulary (fulcrum, load, effort) from their investigation Katherine L. McNeill ([email protected]) is an assis- in their evidence to support their claim. tant professor of science education at Boston College in Chestnut Hill, Massachusetts. Dean M. Martin was a third- through fifth-grade science teacher in Boston, and Providing Support Over Time is currently an elementary and middle school profession- Helping students develop strong scientific arguments al development specialist for the Boston Public Schools during discussion and in writing takes time. After the in Massachusetts. lever investigation, we continued to provide students with writing prompts on their investigation sheets and References Mr. Martin included a variety of teaching strategies in Lawrence Hall of Science. 2005. Full option science system: his instruction. He used instructional strategies such as Levers and pulleys. Nashua, NH: Delta Education. modeling and critiquing samples of writing, connect- McNeill, K.L., and J. Krajcik. 2008a. Assessing middle school ing to everyday examples, and providing students with students’ content knowledge and reasoning through feedback (McNeill and Krajcik 2008b). written explanations. In Assessing science learning: Reasoning was the most challenging component Perspectives from research and practice, eds. J. Coffey, R. for his students to grasp. One strategy we used to help Douglas, and C. Stearns, 101–116. Arlington, VA: NSTA students understand what counts as good reasoning was Press. to discuss examples of both strong and weak reasoning McNeill, K.L., and J. Krajcik. 2008b. Inquiry and scientific statements. For example, Figure 4 illustrates a multiple- explanations: Helping students use evidence and reason- choice task in which students had to select which rea- ing. In Science as inquiry in the secondary setting, eds. J. soning statement was the strongest for an investigation Luft, R. Bell, and J. Gess-Newsome, 121–134. Arlington, focused on the question “Does friction affect the distance VA: NSTA Press. a car travels?” McNeill, K.L., and Krajcik, J. 2011. Supporting grade 5–8 stu- Over the course of the school year, Mr. Martin pro- dents in constructing explanations in science: The claim, vided his students with a variety of different supports. evidence and reasoning framework for talk and writing. His fifth graders became better able to make sense of Boston, MA: Pearson Education. their data and appropriately share the results of their Michaels, S., A.W. Shouse, and H.A. Schweingruber. 2008. inquiry investigations in which they justified the claims Ready, set, science! Putting research to work in k–8 sci- they made with evidence and reasoning. n ence classrooms. Board on Science Education, Center for Education, Division of Behavioral and Social Sciences and Education. Washington, DC: National Academies Press. Figure 4. Does friction affect the distance a car travels? NSTA Connection Download the rubric at www.nsta.org/SC1104. Circle ONE of the following. A. The data showed us that the car traveled the farthest distance on linoleum, a medium distance on sandpaper, and the shortest Connecting to the Standards distance on the rug. That is why my evidence This article relates to the following National Science supports my claim. Education Standards (NRC 1996): B. Friction is a force that resists motion. The rug Content Standards had the roughest surface so it had the most Grades K–8 friction. The linoleum was smooth so it had Standard A: Science as Inquiry the least friction. So the greater the friction, Abilities necessary to do science inquiry the shorter the distance the car will travel. Understanding about science inquiry C. We had fun doing this experiment in class. Standard B: Physical Science The data showed that the greater the friction, Motions and forces the shorter the distance a car travels. All of National Research Council (NRC). 1996. National the groups got the same results so that is how science education standards. Washington, DC: we know it is true. 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