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Chemistry: Argument using CER

This Guide is specially created to help chemistry faculty and students find the best resources in the library.

How to write an argument using CER

How to write an argument using CER (Claim, Evidence, Reasoning)
For Introductory Chemistry


Claim: It is an answer to your question. It is also a conclusion you have drawn from the data or sometimes it is called a thesis (in English class).

Evidence: This is the data you have from your experiment that supports (or backs up) your claim. It may be observations, measurements, calculations, or other information from your experiment. In other courses, it may be facts from credible sources. The evidence should be appropriate, sufficient, and free of inference. This means you are not making generalizations or beliefs about the data, but you are giving hard evidence (measurements and observations) to support the claim.

Reasoning or Justification: it is what links together your claim and evidence. It is usually the 
why. Often it will be a scientific principle, law, definition or rule that will explain the concept that is occurring in the experiment. You will likely learn many of these in the classroom; however, you may need to use credible sources other than the classroom to find the logic that will bring your claim and evidence together.

1. After completing the experiment and evaluating and analyzing your data, answer your question posed at the start of lab. Write a one-sentence answer (the claim).
2. Determine which data from the experiment can be used to support the answer. Write out several sentences (depending on how much data you have) to support the claim using actual numbers or observations from your experiment.
3. Determine what reasoning you will need to connect the claim and evidence together. This may require looking through your notes, textbook or credible sources online.
4. If you have more than one question or claim, make sure to have evidence and reasoning for each claim.
5. If you have negative data, explain how this data does not support the claim and why it does not.

Citation Writing Types: Claim-Evidence-Reasoning
Accessed Aug 27, 2017.