This post is to help anyone starting out with CER get started. If you aren’t sure what CER is or are interested in why I use it, click here; which includes a scaffolding tool, rubric, and helpful steps. Obviously, it helps to start this at the beginning of the year when you are setting all of your expectations, but I learned that it isn’t absolutely essential. I stumbled on some labs that used CER and decided to use them and go for it in the middle of the year. Even starting this in the middle of one year (and honestly, not being all that great at it), I still noticed a big difference in how the students wrote their answers. The next year, I decided to start at the beginning of the year. Luckily, the summer training I was required to do was led by a teacher that used this for his AP Biology class and there were some great ideas.
First, make it easier on the students and start with some non-academic examples. We started with some commercials that we used to write out our examples. If you do a YouTube search for “Audi Alien Dad” and “Audi Prom” you will find the videos I have used. There are plenty out there. The “Alien Dad” is actually a great starting point. The little girl makes a claim and then gives all her evidence. As a class, we wrote out the Reasoning together. The prom commercial is a little more vague and they have to draw their own conclusions about how the guy got a black eye. Some of my classes got really into this one and I let them write their own reasoning. The thing to make sure it that they don’t skip steps. Many of them wanted to skip the part about how they knew the guy had been hit. The black eye is evidence, but they need to include the facts they know-getting hit hard causes black eyes. Total, this took about 20 minutes and I did it on Day 2. Day 1 is usually the start of a lab and we are writing our conclusions on Day 2.
After the introduction, they wrote the conclusion for their lab from the previous class. With my on-level classes we did a Double-Stuf Oreo Lab that you can find here. My advanced classes I actually do a brine shrimp lab. This is an AP Bio lab that has been modified (not by me, but I don’t remember where I got it). It is a great lab for the start of the year; I think it gets them interested pretty quick and if they don’t follow the instructions and mess it up, it will not effect their knowledge of the content 🙂
For my on-level classes, they did not need the scaffolding tool that can be found on the introduction to CER post for this lab. The content was fairly simple; the only thing I made them include was how they knew that the stuffing was twice as much, so they explained the math. This gives them the chance to understand how to do the writing while already understanding the content; when it is time to repeat the writing with new content, it will be easier.
Another teacher gave me the idea to have the lab groups create a poster with their Claim, Evidence, and Reasoning. Then, I give each student 2 sticky notes and they go grade each other’s posters and give feedback for what could be improved. Before I grade them, the groups get the chance to go back and look at the feedback and fix anything they need. This serves 3 purposes-first, the evaluators get the chance to see what their classmates wrote and decide if they should change anything. Second, the groups get to fix any mistakes before I grade it. Third, the grading goes much faster because they have usually fixed most of their mistakes.
If you are writing formal lab conclusions and would like to include sources of error, it is easy to do. Students can add the information to the evidence or reasoning:
- Evidence-this is what happened in lab! Have them add this here as an extra sentence or 2.
- Example: During lab, the cold enzyme and the cold peroxide had a reaction rate of 5. However, this could have happened because we didn’t pour the peroxide slowly down the side of the test tube as instructed. The cold should have reacted slower than the room temperature and warm peroxide.
- Reasoning-this is the content. Why did this not match what should have happened?
- Example: Enzymes catalyze reactions when they have a collision with the substrate. Cold molecules move slower, so the cold peroxide and cold enzyme should have had fewer collisions and resulted in a slower reaction rate. Â
Either way, you can clearly see that they understood the content and the lab and made a connection between them.
This format is easy to learn, but it is important to use it often! Be consistent in your expectations. I expect them to use CER in all writing that we do. You don’t have to redo all your labs, but you can changed one question to CER. If you are having them write a conclusion, make it CER format. We use this for short answer questions, bellringers that require writing, and anything else I can think of. We do this often enough that they actually start to do this without me telling them to! I know, that part is probably hard to believe.
If you have any questions, feel free to ask and I will do my best to help!
