CER Format for Chemistry Lab Conclusions

Claim-Evidence-Reasoning Format for Lab Write-ups in Chemistry 2014
CLAIM: Answer the question at the beginning of the lab (1 sentence)
EVIDENCE: Describe the evidence that supports the claim. Use observations and data (with
units) from your lab results. (At least 3 sentences)
REASONING: Explain how the evidence that your described supports the claim that you made.
This is the “because” section. Often you will need to refer back to basic scientific
principles (I.e. “Substances 2 and 4 were the same because they had the same
properties. Substances with the same properties are most likely samples of the
same substance.”) (At least 3 sentences)
ERROR ANALYSIS: Describe results of any error analysis calculations: 5% rule for y-intercept,
% error, etc.
Describe at least 2 possible sources of error in the lab. Be specific. ”Human
error” and “measurement error” are NOT specific. Think of possible errors in
processes you use in lab.