Scientific Explanations

Scientific explanation are different from everyday explanations because they are based on evidence. Science students need to explain conclusions that they reach, from taking data, in a clear way. Claim, Evidence and Reasoning is a format that makes writing very complex ideas, a little easier. When you are writing a paper, answering questions on a quiz or CSAP, you have a much greater chance of proving what you know if you use the CER format.


This is the idea that you are trying to prove. In English class, you would call it a thesis statement. It could also be the introductory paragraph in a paper


This section will be very dry. You should describe graphs and outline evidence. Your own thoughts will go in the reasoning section. Evidence should include:
  • Studies that support your claim
  • Data
  • Analysis
  • Facts


This is where you will put your ideas about what the evidence means. Reasoning explains why evidence came out the in the way that it did. Reasoning should include:
  • Your ideas on why graphs have a particular shape.
  • Your ideas on why your claim is true.
  • You should reach logical conclusions based on evidence.
  • Build your argument to prove your point.