Free 4-point CER rubric for science and ELA, with a scored sample.
A CER rubric is a scoring guide that rates the claim, the evidence, and the reasoning (CER) in a student response as three separate rows. At Chalkbox, we build free classroom tools and guides for K-12 teachers, and the four-level rubric below is our own design for you to copy and adapt. Each part gets its own score, so you can tell a student exactly which part needs work instead of handing back one number.
Chalkbox's four-level CER rubric scores Claim, Evidence, and Reasoning from 4 down to 1, so a complete response earns 12 points. Every level has a written description, and that description is what lets you say which part of the paragraph fell short.
The three rows score these parts:
| Row | 4: Complete and precise | 3: Mostly there, one gap | 2: Partial or vague | 1: Missing or wrong |
|---|---|---|---|---|
| Claim | One sentence that answers the question directly and accurately | Answers the question but runs past one sentence or mixes in explanation | Only partly answers the question, or is too vague to test | No claim, or the claim does not answer the question |
| Evidence | Specific data, observations, or quotes, enough of them, all supporting the claim | Specific and relevant, but one piece is missing, unclear, or there is not quite enough | General or vague, or only partly supports the claim | No evidence, or the evidence is an opinion or unrelated |
| Reasoning | Explains why the evidence supports the claim and names the science idea, rule, or text logic that links them | Explains the link, but the idea or rule is named loosely or one step is skipped | Restates the evidence, or states a link with no explanation | Missing, or contradicts the evidence |
This rubric is an original Chalkbox design. It is a model to adapt and is not a published or official standard, so rewrite any descriptor to match your question and your students.
The science version and the English language arts (ELA) and social studies version keep the same three rows and the same 4-point scale, but they ask for different evidence and reasoning at the top level. The table shows what a level 4 response needs in each subject.
| Row | Science (level 4) | ELA and social studies (level 4) |
|---|---|---|
| Claim | One sentence that answers the investigation question | One sentence that answers the prompt about the text or source |
| Evidence | Measurements with units, and enough data points to support the claim | Quotations or details cited accurately from the text or source, and enough quotes to support the claim |
| Reasoning | Names the scientific principle that links the data to the claim | Explains how each quote supports the claim instead of repeating the quote |
To score levels 3 to 1, count how many of those requirements are missing. A science response with numbers but no units, or with a single data point, fits level 3 on Evidence. An ELA response that quotes accurately but then paraphrases the quote as its reasoning fits level 2 on Reasoning.
The sample below is an original Chalkbox paragraph written to show the CER rubric in use. Its numbers are invented for the demo and are not real data.
The question is "Does adding salt change how fast ice melts?"
Salt makes ice melt faster. In our class trial, a cup of ice with salt melted in 6 minutes, and the same amount of ice without salt melted in 10 minutes. Salt lowers the freezing point of water, so ice at the same temperature melts.
Here is how the science version scores it, with one feedback comment per row:
| Row | Score | Why | Feedback comment |
|---|---|---|---|
| Claim | 4 | One sentence that answers the question directly | "Your claim answers the question in one sentence. Keep doing that." |
| Evidence | 3 | Two measurements with units, but from one trial, so there are not enough data points | "Add a number that proves it: run the trial two more times and report each result." |
| Reasoning | 3 | Names the principle (salt lowers the freezing point) but does not tie it to the faster melt | "Tell me why this evidence proves your claim. Connect the lower freezing point to the 4-minute difference." |
The paragraph earns 10 of 12 points. The 4-minute difference in the reasoning comment comes from 10 minutes minus 6 minutes. The student walks away with a specific next step for two rows, which a single grade at the top of the page cannot give.
Three comment stems you can use for rows that score below 4:
Turning rubric points into a grade is your choice or your district's choice. One illustrative conversion is to divide the points earned by 12, then multiply by 100.
The sample paragraph scored 10 points, and 10 divided by 12 is about 0.83, or 83 percent. Where you place the line between letter grades is up to you, and Chalkbox sets no cut-offs here. You can also record the three row scores without converting them, which shows at a glance whether a student needs practice on claims, evidence, or reasoning.
Some teachers add a fourth row called Conventions or Clarity, which covers grammar, units, and sentence structure. The row is optional and not required for a CER task.
Score it separately from the three CER rows, so a spelling slip does not pull down a strong reasoning score. If you use the same 4-point scale for it, the total rises to 16 points, and the grade math becomes points earned divided by 16.
Units show up in two places once you add this row: the science Evidence descriptor and the Conventions row. Decide ahead of time which row counts them, so one missing unit does not cost a student points twice.
Five scoring problems come up often with CER paragraphs, and each has a direct fix:
You can share the CER rubric with students before they write and have them use it on their own drafts. Four ways to use it in class:
This four-level rubric fits a single CER paragraph, and it is the wrong tool for a full lab report. For a lab report, build a separate rubric in the free Rubric Generator. If you want a quicker 0 to 2 version, the CER Template page includes one next to a printable organizer; the rubric here is more detailed. For team assignments, see the Group Project Rubric.
Our CER Examples page has annotated models. If you are introducing claim, evidence, and reasoning for the first time, start with How to Teach CER before you hand out the rubric.
Score claim, evidence, and reasoning as separate rows, give each a score from 4 to 1, and write one feedback comment per row. Copy the four-level CER rubric above, rewrite the descriptors for your next question, and hand it to students before they start writing.
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A CER rubric is a scoring guide that rates the claim, evidence, and reasoning in a student response separately, each on a short scale with a written description per level. Chalkbox's version uses four levels, scored 4 to 1, across three rows for a total of 12 points. Because each part has its own score, you can show a student exactly which part needs work.
The three parts are claim, evidence, and reasoning. The claim is a one-sentence answer to the question, and the evidence is specific data, observations, or quotes that support it. The reasoning explains why the evidence supports the claim and names the science idea, rule, or text logic that links them.
A common mistake is reasoning that only restates the evidence. The student repeats the numbers or the quote but never explains why they prove the claim, which fits level 2 on the Chalkbox rubric. Other common problems are evidence that is an opinion and claims that pack the explanation into the first sentence.
Score one row at a time and use short feedback stems. Read every paper for the claim first, then the evidence, then the reasoning. For a fast formative check, use a one-row mini-rubric and score only the part the class is practicing.
Yes, the three rows and the 4-point scale work for both subjects, but the descriptors should change. A science version asks for measurements with units, enough data points, and a named scientific principle. An ELA or social studies version asks for accurately cited quotations or details, plus reasoning that explains how each quote supports the claim instead of repeating it.