Authentic Lessons for 21st Century Learning

Claim, Evidence, Reasoning (CER)

K20 Center | Published: September 16th, 2020 by K20 Center


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Claim, Evidence, Reasoning (CER)

This strategy provides a scaffolded way for students to use evidence to formulate and justify their own arguments by breaking down materials and research into smaller pieces for analysis.

Claim, Evidence, Reasoning (CER)


This critical thinking strategy allows students to use evidence to substantiate claims to answer a posed question. Students will write a conclusion that justifies their claim and supported evidence. 


  1. Present students with a question that allows them to create a claim. The claim will answer the question and will usually be one sentence.

  2. Next, students will look for evidence to support their claim in materials and online research provided. The more relevant the evidence, the better the claim will be supported.

  3. Students will write their reasoning, which acts as a conclusion, providing explanations for why the data they chose counts as evidence and supports their claim. This should be a few sentences in length.

  4. ELA variation: Students look at a persuasive text (science journal article, newspaper column, etc.). They annotate the article by labeling the author's claim, evidence, and reasoning. Students could also write the claim, evidence, and reasoning on a large paper to allow their classmates to see if they all gathered the same components or if there were different perspectives.

McNeill, K. L., & Krajcik, J. (2008). Inquiry and scientific explanations: Helping students use evidence and reasoning.