1. Claim, Evidence, and Reasoning
How to write a scientific explanation

2. Claim Most labs start with a question.
Your claim answers your original question.
The claim is usually one sentence.
It must be accurate, specific, and fully answer the question.

3. Evidence
The evidence is all of the scientific data and observations that support your claim.
Evidence must be sufficient and relevant to your claim. Not all data is considered evidence!
Most evidence is specific data from the lab. This can come from your own group or another group in the class.

4. Evidence
On the left side of the form, write the actual data or observation that is relevant to your claim.
Remember: there are a lot of observations that are important to make, but irrelevant to the claim.
On the right side of the form, for each piece of evidence, provide the scientific background that tells why that is a relevant piece of data.

5. Ex: LEFT SIDE
The seed was 0.3 cm wide on day 1. On day 2 it was 0.35 cm wide and had a sprout that was 0.2 cm long.
The rock was 0.7 cm on day 1 and was still 0.7 cm on day 5.
RIGHT SIDE
The seed absorbed water and grew.
The rock did not grow.

6. Explanation
Explanation is the explanation that pulls together your claim and the evidence that supports it.
It shows why the data you chose counts as evidence.
This explanation acts as a “conclusion” of your experiment.

7. Reasoning
It shows a detailed understanding of the scientific principles involved and uses correct science vocabulary.
The reasoning should usually be several sentences in length.