Supporting Claims with Evidence and Reasoning
Chemistry teacher Martin Berryman shows how to help students write strong claims based on evidence, reason, and the interpretation of data.
Teacher: Martin Berryman
School: Malden High School, Malden, MA
Discipline: Science (Chemistry)
Lesson Topic: Gravimetric analysis
Lesson Month: December
Number of Students: 32
Featured Lesson’s Student Goals:
- Content objectives – Design an experiment and/or interpret data to determine the empirical formula of a compound using gravimetric analysis techniques; construct thoughtful and testable beginning questions; investigate the characteristics of a strong claim; construct claims; construct evidence to support claims; compare the claim and evidence to literature values
- Literacy/language objectives – Focus on academic language, such as claim, evidence, and hypothesis
- Engagement/interaction objectives – Construct knowledge in small, self-managed groups with specifically defined roles; utilize teamwork, oral and written communication, management, problem solving, information processing, and critical thinking
A Framework for K–12 Science Education
- Asking questions (for science) and defining problems (for engineering)
- Developing and using models
- Planning and carrying out investigations
- Analyzing and interpreting data
- Constructing explanations (for science) and designing solutions (for engineering)
- Engaging in argument from evidence
- Obtaining, evaluating, and communicating information
Common Core State Standards for English Language Arts & Literacy in History/Social Studies, Science, and Technical Subjects
Write arguments focused on discipline-specific content.
Write informative/explanatory texts, including the narration of historical events, scientific procedures/experiments, or technical processes.
Follow precisely a complex multistep procedure when carrying out experiments, taking measurements, or performing technical tasks, attending to special cases or exceptions defined in the text.
Produce clear and coherent writing in which the development, organization, and style are appropriate to task, purpose, and audience.
The goal for this 10-day unit was for students to understand that chemical elements are fundamental building materials of matter and that all matter can be understood in terms of arrangements of atoms, which retain their identity in chemical reactions. The lesson on gravimetric analysis occurred in the middle of the unit, and the students had already performed laboratory work.
Before the Video
During the previous class, students performed laboratory tests by heating a hydrate salt to determine its empirical formula. Each group was given a hydrate salt with a different initial mass.
During the Video
The students’ task was to construct a quality claim about a beginning question by examining evidence and calculations from the previous day’s lab. The beginning question was: Does the empirical formula of a hydrate depend on the initial mass? Mr. Berryman provided guidelines for a quality claim: it should be a statement about the results of their lab work, be one to two sentences in length, and answer the beginning question.
To help students understand what makes a strong claim, Mr. Berryman asked the groups to review and discuss two claims and choose the strongest. Then, in small groups of four, students wrote down observations about their hydrate salt lab and constructed claims based on these observations (which would later provide the evidence they would need to support their claim). As a large group, Mr. Berryman and the students reviewed the characteristics of strong evidence. Mr. Berryman then asked students to examine their evidence to justify their claims. Groups pooled their data to determine the answer to the beginning question: the empirical formula of a hydrate does not depend on the initial mass (rather, it depends on the mole ratio). Students wrote a short essay to summarize their findings.
After the Video
Students did a close reading of scientific literature to compare their findings to published findings. Rather than rely on him to tell them whether they “got it right,” Mr. Berryman wanted students to be able to compare their claims to those of scientists in the field.
Throughout the year, Mr. Berryman collaborated with teachers in the English department to create a common curriculum based on claims, evidence, and reasoning. When preparing his lesson, Mr. Berryman used the POGIL approach (Process Oriented Guided Inquiry Learning), a student-driven cycle of investigation, construction of ideas, and application of what was constructed. Students worked in small groups with assigned roles to investigate claims and determine which was the strongest, construct the concept, and apply that concept to what they did in the lab.
To participate in this lesson, students needed basic algebra skills and a basic understanding of matter as a solid, liquid, and gas. Students also needed to know how to write chemical equations, how to analyze a hydrate, and how to classify matter.
Mr. Berryman used vocabulary as “the window” into understanding the content (especially for English language learners). He used a word wall and a Moodle website (a free web app that allows for interactive vocabulary within posted assignments—key words are highlighted, defined, and represented visually).
For all lessons, Mr. Berryman encourages students to connect with content on three levels: macroscopic, microscopic, and representatively. If time had permitted after this lab, students would have written an expression of the chemical equation, drawn diagrams of the chemical equation to imagine what was happening at the microscopic level, and then written an explanation of what did happen.
Students worked in small groups of four, each with a specific role. The group leader facilitated data analysis and reflections about results; the quality controller analyzed data from other group members to ensure accuracy; the speaker reported out to the class on his or her group’s findings and presented the group’s claim; the group analyst presented the collected evidence and data that supported the claim.
Throughout the year, Mr. Berryman emphasized routines and set expectations to create a structured environment in which students feel free to contribute, ask questions, engage in discussion, and make presentations. He used a hand-raising strategy to get students’ attention and quiet the room as well as a cold-calling technique to keep students on task and accountable. He offered extra-credit “5-point cards” to keep students motivated. (They could “cash in” 100 points to raise a grade.)
Mr. Berryman encouraged collaborative teamwork and often grouped students in small groups. (He also felt that small groups helped with classroom management.) He used assessments and diagnostics to group students based on how they think. When students worked in groups, he focused on process skills and interpersonal effectiveness—his “rules of engagement” for students included listening respectfully, maintaining eye contact, being loud enough to be heard, using peers’ names, and respecting all opinions.
Resources and Tools
- PowerPoint Presentation: “How Do Chemists Communicate Their Findings?,” created by POGIL (Process Oriented Guided Inquiry Learning)
- Claim Evidence A, created by POGIL
- Claim Evidence B, created by POGIL
- “The Science Writing Heuristic Lab Report Format” by Thomas J. Greenbowe
- “Determination of the Percent of Water in a Compound and Its Empirical Formula” adapted from Advanced Chemistry with Vernier & Laboratory Experiments for Advanced Placement Chemistry by Sally Ann Vonderbrink, PhD
- Role cards
- Moodle website
- Process Analyst Report Form, created by POGIL
Mr. Berryman observed students throughout the lesson. At the end, he projected a problem that was similar to the lab challenge. Students worked individually to solve it and submitted their answer using a process analyst report tool (clicker). Mr. Berryman aggregated the answers and discussed the class results.
Students assessed their own group work using the process analyst report tool. They also assessed their understanding of the objective (on a scale of 1 to 5) by writing the number on a sticky note and hanging it on the board. Together, the class analyzed the responses.
Mr. Berryman assessed students’ final lab reports using the Science Writing Heuristic—an instructional design model. Grades were given based on accuracy of results, interaction with other members of group, and how well students fulfilled their group roles.