Transcript Claims, Evidence, Reasoning

Claims, Evidence,
Reasoning
What is it?
 In science, an answer you give must be supported with
data, and that data must be interpreted.
 CER is a logical way to ensure that you answer the
question, provide data, and interpret what that data
means with respect to the question.
 Always answer the question with a claim, evidence,
and then reasoning.
What are they?
 Claim: “A statement or question that answers the
original question / problem.”
 Evidence: “Scientific data that supports the claim. The
data needs to be appropriate and sufficient to support
the claim.”
 Reasoning: “A justification that connects the evidence
to the claim. It shows why the data counts as evidence
by using appropriate and sufficient scientific principles.”

Source: http://www.nsta.org/elementaryschool/connections/201104ClaimsEvidenceRubric.pdf
Example:
 Question: Which of the following is more dense: a ball
made of lead, or a ball made of wood having the same
volume as the lead ball?
 Claim: The lead ball is more dense.
 Evidence: The lead ball’s mass 50 g, while the wood
ball’s mass is 40 g.
 Reasoning: Because the lead ball’s mass is 10 g greater
than the wood ball’s mass, and
mass
density =
volume
the lead ball must have a greater density.
Practice
 Identify the following as a claim, evidence, or
reasoning:
 The 400 g car was displaced 30 cm after the collision,
while the 200 g car was displaced 60 cm after the
collision.
 The heavier the car, the less distance the car will be
displaced after colliding with another car.
 The two cars moved with the same speed prior to the
collision. After colliding, the car with the greater mass
was displaced a smaller distance because it takes a
greater amount of energy to move a larger mass.