Do your students ever ask, “How do we know that’s true?” I’m always happy when mine ask that question! It means they are thinking like a scientist and using the claim, evidence, and reasoning framework in your middle school science classroom. This critical science skill is key to implementing an inquiry-focused classroom. And the best part is it’s really pretty easy! Keep reading to see how to use it in your classroom.
Why does the CER framework matter in middle school science?
We work to keep students curious, but it's easy to answer their questions too fast. The best questions can't be Googled — they need evidence that has to be collected. CER gives students a structured way to answer those questions themselves instead of waiting for the answer.
Students like to ask questions. As science teachers, we strive to cultivate that curiosity about the world around us. However, I know that I am often too quick to provide the answer to students. They want to know an answer to their question – and who can blame them? Most questions can be answered by Google immediately.
But, the best questions cannot be answered by a Google search. This is because they require evidence that must be collected. That is something Google cannot do yet.
What are the three parts of the CER framework?
CER is a step-wise way to answer a scientific question. Students start with a question, make a claim to answer it, collect evidence (data or facts) to defend the claim, then write a reasoning statement that ties the evidence to the claim using a scientific principle. Each step depends on the one before it.
The claim, evidence, and reasoning framework (often shortened to CER) is a step-wise way to answer a scientific question.
First, students are presented with a question: “Why does the Earth have seasons?”
Next, they make a claim to answer the question. Depending on your students’ level of comfort taking guesses, they could generate these claims or you could provide them with a choice of two. Consider limiting the number of possible claims as you build this skill with your students.
“The Earth has seasons because it is tilted on an axis.”
OR
“The Earth has seasons because it is closer to the Sun in the summer and farther from the Sun in winter.”
Next, students collect evidence to defend their claims. The type and amount of evidence will depend on the claim they are trying to defend. Evidence can be data from experiments or facts.
“The Sun moves at different positions in the sky during different seasons.”
“While summer occurs in the northern hemisphere, winter occurs in the southern hemisphere. The same season is not occurring all over Earth at the same time.”
“There are more hours of daylight in the summer and fewer in the winter as you get closer to the poles in both hemispheres.”
Finally, students make a reasoning statement using their evidence to defend their claim. Their reasoning statement should explain why or how the evidence supports the claim. It should also include a scientific principle as a basis.
“The Earth spins on an axis pointing the northern hemisphere more directly at the Sun in May through August and the southern hemisphere in November to February. This can be observed by measuring the track the Sun moves across the sky in different seasons. If seasons were based on how close the Earth was to the Sun, both hemispheres would experience the same seasons at the same time.”
What is the purpose of the CER framework?
CER teaches students to use evidence to defend ideas and to update those ideas when new evidence appears. The parts fit together: the claim tells you which evidence to gather, and the reasoning glues evidence to claim with a scientific principle. Unlike a hypothesis, a claim should change when evidence doesn't support it.
It is vital that students can use data/evidence to defend their ideas – both in a science and non-science setting. It is also important that they evaluate new evidence, determine if their claim is still true, and then decide whether to amend or discard it.
A key feature of the CER framework is how each component works together in a step-by-step way. The claim tells you which evidence you need to collect. The reasoning statement should be able to “glue” the evidence to the claim using a scientific principle.
And, in my mind, here is how a claim is different than a hypothesis. We teach students that they should not change their hypothesis during an experiment just to “get the answer right”. However, a claim SHOULD be changed during the discovery process is evidence does not support it. I believe this is a fantastic life lesson for students to understand. It’s okay to change your idea if new evidence comes along – and it’s the basis of how science works to understand the world around us.
How do you introduce CER at the start of the year?
Most students have never used CER in science, though they may know it from English. I scaffold heavily: introduce one component at a time with examples, have students pick the best option before writing their own, and finish with a graphic organizer that walks through all three steps in the context of an experiment.
Most of my students have never used the claim, evidence, and reasoning framework in a middle school science setting. They may have some familiarity with it from English class. But, connecting it to science seems strange to them.
I heavily scaffolded this unit by giving students examples of each component and asking them to choose the best choice. This is less intimidating to students than developing their own CER framework at this stage. Here is my teaching strategy for this unit:
- I give students to term claim and examples of it using cloze notes. Then, we practice making a claim from collected evidence. They choose the best claim from is best supported by the evidence. I also ask them to explain why each claim is or is not the best.
- Next, I give students the term evidence. Then, I give them a reading passage about an experiment. Several parts of the reading are pulled out and students decide if they are or are not evidence. This helps students understand the difference between evidence that supports a claim and evidence that does not.
- Then, I give students the term reasoning. Students read about an experiment and evaluate data. Then, they decide which reasoning statement best connects the evidence to the claim.
- Finally, we complete a graphic organizer of each step in the context of an experiment: “Why does light seem so bright when you leave a dark room?”
Link to CER Middle School Science Unit
What are some examples of teaching CER in class?
You can run CER with zero prep. Start with non-science examples like ad claims or predicting a story's next event, then move to science questions students already have background on — whether plants need soil, whether light travels in straight lines, or whether sound needs a medium — each worked through claim, evidence, and reasoning.
There are so many interesting and fun examples that you can employ the claim, evidence, and reasoning framework in your middle school science classroom – all without any preparation! Here are some ideas with examples of questions to pose to students with the connecting claim, evidence, and reasoning.
Before beginning with science examples of the CER framework, you can use non-science examples.
- Some commercials make claims about their products. Ask students to identify the claim the advertisement is making and the evidence they cite.
- Read a short story and ask students to make a claim about what would happen next. They should cite evidence from the text and make a reasoning statement that defends their claim with the evidence.
You can also use scientific examples for which your students may already have background knowledge. Here are a few examples:
Question: Do plants need soil to grow?
Claim: Plants do not need soil to grow.
Evidence: Some plants grow in nature without soil such as air plants that grow high the tree canopy of the rainforest on top of other trees.
Evidence: Astronauts grow plants in the International Space Station (ISS) without soil.
Reasoning: Plants get only a small amount of nutrients they require from soil. Most of their mass comes from water and carbon dioxide. Nutrients (such as minerals) can be given to the plant without soil.
Question: Does light move in a straight line?
Claim: Light travels in straight lines.
Evidence: Shadows cast by objects from a flashlight appear directly behind the object.
Evidence: During a sunrise, you cannot see the Sun until it appears over the horizon.
Reasoning: Light travels as a wave through empty space and energy takes the shortest distance to travel between two points. However, light can be affected by gravity such as black holes.
Question: Does sound require a medium to travel through?
Claim: Sound requires a medium to travel through.
Evidence: Sound travels through air easily. It can also travel through liquids and solids.
Evidence: Sound does not travel through vacuums like outer space in which there is no medium.
Reasoning: Sound requires atoms to move back and forth to carry the sound energy. In a vacuum, there is no medium for sound energy to move atoms back and forth.
How do you integrate CER throughout the school year?
Build units around an anchor phenomenon and use CER as the mystery to solve. But CER also works small — after a reading passage, after collecting experiment data, anywhere you have a question and evidence. Once students are comfortable, include CER on assessments in identify-choose-write formats.
One way to use the claim, evidence, and reasoning framework throughout the school year is to build your units around an anchor phenomenon. These can be done in many ways but I prefer using them as “mysteries to be solved” throughout the unit. Ideally, all the information in the unit will be necessary to explain the anchor phenomenon.
While CERs can be large, detailed parts of a unit, they can also be used in smaller ways. They are great to be used with reading passages about a science concept. They can be written after collecting data on an experiment within a unit. As long as you have a question to be answered and data or evidence that can be cited, you can use the CER framework.
Once students become familiar with the framework, I like to include them as test questions on assessments. This can be done by having students identify a claim on the unit material, decide which evidence best supports a given claim, and write their own reasoning for given claims and evidence, or any combination of these!
Is there a CER digital escape room?
Yes. Digital escape rooms bring collaboration, critical thinking, and content review together, so I made one to practice the CER skill specifically. It's a fun, low-stakes way for students to apply claim, evidence, and reasoning while working together.
It’s no secret that I enjoy using digital escape rooms in class. They offer so many benefits – collaboration, critical thinking, and content review! I made one to practice this skill as well. If you’d like to check it out, click on this link to go to my TeachersPayTeachers store.
What are common challenges when using CER?
Critical thinking hasn't been central to most students' schooling, so defending a claim can be hard even when it seems simple. Building the skill takes patience: students may struggle with logic or push back on wording. Stay encouraging but keep expectations high, and press them to connect evidence to claims.
Let’s face it. Critical thinking has not been a required part of schooling for most of our personal education. A lot of our courses focus around facts and implementation of those facts. Asking students to defend a claim, while on it’s surface seemingly straightforward, can be difficult for middle schoolers.
As with most activities we do as teachers, it takes patience to build this skill in our students. They may struggle with logical thinking. They may disagree when we critique their wording.
Remember to be encouraging as they build this skill. But, also have high expectations. Press them to explain how their evidence supports a claim if it is not obvious. Give them conflicting evidence and have them defend their claim in light of it. Developing these skills are not easy but will be so beneficial to them in their future – whether as a scientist or a citizen.
The claim, evidence, and reasoning framework builds a skill in our students that they will depend upon for the rest of their lives. Defending their ideas and incorporating new evidence is something they will need to be able to do throughout their education career, future job, and as a citizen. I like to think that this is one of the most useful skills I teach in my class. While they will probably forget the names of Earth’s geologic eras or all parts of the water cycle, critically analyzing evidence is a skill they may use every day.