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How to Teach CER Basics in Your Science Classroom

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I struggled to help my students become better science writers. But once I started chunking the information and doing lots of practice I saw improvements in their writing. One strategy that definitely helped was using CER writing. Read on to find some tips that you can implement right away for how to teach CER basics to your students. There’s also a link to a free checklist and graphic organizer that your students can use.

Image of students writing CER basics

How to Teach CER Basics 

CER, or Claim – Evidence – Reasoning, is a structured writing method that helps students think and write scientifically. When students are able to find evidence to support their claim and then explain how and why it does so, they are more able to make connections and understand the science concepts behind their claim. Read more about teaching CER here.

The Claim

Students make a claim based on the evidence they find in the source material. Some tips for teaching Claim:

  • If students can understand how this writing method works with a non-science idea it will make it easier for them to understand how to write a CER on a science topic. I like to use television commercials. There are several that are funny and students enjoy “defending” their claim with reasoning. This is a cute Youtube video titled “My Dad’s a Space Alien.”
  • Start out with evidence that contains an obvious claim. Reading passages are a good source for straightforward evidence statements. 
  • When you’re just starting to teach CER basics, give students a question to answer as their claim that’s based on the evidence source. This can be a straight yes or no question. 
  • Give small snippets of evidence and let students practice making claims about them. 
  • As students get better at making claims, start giving them different types of source materials such as graphs, charts, and illustrations. 
  • Move on to giving students evidence sources without building in the question for them. The goal is for them to study the evidence and come up with their own claim.


  • Give your students as much variety as you can in the types of source material they use. 
  • Model finding the evidence in the different types. I like to use my document camera to go through the source with the class, thinking out loud and asking questions to help them decide on what is evidence and what is not.
  • It’s ok to give them even more structure. For example I tell my students that 2 pieces of evidence is the minimum they should find, and 3 is even better.
  • Get them in the habit of annotating and highlighting the evidence they find. This will make it easier for them when they’re writing the Reasoning part. 


This is usually the part where students have the most difficulty. They need to have at least a basic grasp of the science concepts behind the source material.

  • Sentence starters can be a big help here, especially in the beginning. Examples might be “All of the evidence proves ______ because ______.” Or “Based on the evidence, we can conclude that _____” or  “Using (insert whatever science concept is being used)  explains that _____.” 
  • I’ve found that students think that they need a long explanation in this part. They only need 2 or 3 sentences to show their reasoning.
  • This is where the television commercial CER can be useful. It’s a fun way for them to practice showing the reasoning behind their claim. How does the evidence prove their claim? Let them work in pairs and share their ideas with the class. 
  • Graphic organizers can be really helpful here. Seeing a visual breakdown of their evidence may make it easier to explain their reasoning. It’s also easier to write their reasoning when they can explain one piece of evidence at a time.

Pull It All Together

Teach CER basics by giving your students as much practice and variety as possible. Chunk the process up by section and don’t introduce the next section until you’re confident that your students can handle each one. Provide the level of support needed … you can differentiate instruction by class or even by student by using sentence starters or changing the reading difficulty of the source material. 

This book called Supporting Students in Constructing Claims in Science has some great tips for helping students write concise, logical claims. It’s written for grades 5 – 8 but I’ve also found that it works just as well for high school students. I love this book because it has video clips of classrooms, rubrics, and examples of student writing. I found it to be really helpful as I tried various strategies with my students.

Grab This Free CER Checklist and Graphic Organizer

I’ve put together a checklist that students can keep right in their notebook or binder.

Following the steps one at a time will make it easier for them to complete each section of the CER. There’s also a graphic organizer that’s really helpful as they find the evidence. They can then see each piece of evidence as a separate item which makes it easier to write their reasoning. 

Do you have some tips on teaching CER to your students? Please share!

Hello! Welcome to my little slice of the Internet!

I’m Debbie … retired teacher, curriculum writer, nature-lover, and bibliophile. I love planners, both paper and digital … planning is my “me”time! I live in the Adirondack Mountains of New York State with my husband and our 3 furbabies. That’s me in the picture above with our two horses, Clifford and Shy … they are in addition to our other 3 pets.

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