Claim, Evidence and Reasoning (C.E.R.)

Answering Free Response Questions

  Assessing student learning is as important as it is difficult. To truly teach well, we must understand what our students do and do not understand so that we may facilitate their learning as we move forward. There are many, many different types of assessment each with their own merits. If, however, I really want to get a strong feel for how my students are understanding a topic, I am going to have them write about it. This writing could be a quick write during class, a ticket out the door at the end of class or an assignment that requires free response answers. As a science teacher, however, I struggled with helping students to construct strong free response answers. They may have a sense of the material, but really had difficulty in articulating their understanding. In my many years of teaching, I never had a good solution to help my students to write clear, detailed, yet concise science answers. I would model how I would answer the question myself and this would help a bit, but most students still struggled. On a particularly frustrating day, I brought up this topic with a colleague of mine and she suggested that we ask our local science consultant. It was at this time that I was introduced to C.E.R. = Claim, Evidence and Reasoning.
  CER has really transformed both my formative and summative assessments. I now teach my students this framing for their free response answers and receive on a whole a much better written set of answers on any free response question given. Having the frame helps students to know what components should go into an answer, where they should go in the answer and how those parts should be related.
  When teaching students how to use CER for their answers, I first give them these simple instructions:
1. Claim = your answer. It is probably all that you would put in that blank space after the question unless I forced you to give me a more detailed answer.

2. Evidence = the information that supports your claim. It may be from a lab or from some content that you learned in or out of class, but it backs up your claim.

3. Reasoning = The statement or paragraph that explains how your evidence supports your claim. It is the part of the answer that ties everything together and summarizes the information you are giving in response to the question.

CER can be taught to relatively young science students as early as the middle elementary grades. At the start, have students fill in the parts to the frame. "What is the claim?" What is the evidence?" and What is the reasoning?"As students grow older and have more practice at it, their answers should become more detailed and more fluid. Eventually students should eliminate using the frame as they just write a comprehensive paragraph or paragraphs answer.

  Below are two examples that I would share with students in a middle school physical science class.

EXAMPLE 1 – HOW TO USE C.E.R. FROM A LAB

Lab Question– How does the height of the ramp affect the speed of the car?

Height	Speed
100cm	200cm/sec
60 cm	150 cm/sec
30 cm	110 cm/sec

Question - How does the height of the ramp affect the speed of the car?

Claim – The higher the ramp, the faster the car travels.

Evidence – As the height was increased from 30cm to 100 cm, the speed increased from 110cm/sec to 200 cm/sec.

Reasoning – Therefore as you increase the slope of a ramp you cause the car going down the ramp to go faster as evidenced in our lab. The higher angle of the ramp gives the car more potential energy. This potential energy is then converted into more kinetic (motion) energy as it goes down the ramp.

EXAMPLE 2 - HOW TO USE C.E.R. FROM A LESSON

Lesson  - Acceleration can mean many things in physics. It can mean speeding up, slowing down and even changing direction. The definition of acceleration is the rate of change of velocity.

Question. Two kids are arguing about physics. Richie says that the Earth orbits the sun at a constant speed and is not accelerating, but Litisha says that the Earth accelerates as it orbits the sun. Which physics student is correct?

Claim – Litisha is correct. The Earth accelerates as it orbits the sun

Evidence –Acceleration is any change in velocity.  Velocity is speed AND direction. If the direction changes then the velocity is changing and any change in velocity is acceleration.

Reasoning –Since the Earth is constantly changing direction as it orbits the sun, it has a change in velocity and any change in velocity is acceleration.

CER may appear to be a small addition to your teaching tool belt, but I have found it to make a daily difference in both how my students write and how I am able to assess their understanding. As we move into the age of the Next Generation Science Standards and the Common Core we see the recurring theme of evidenced-based reasoning. The use of CER is an outstanding to aid students in their learning to engage in evidenced-based reasoning!