Handouts are available at the end of this post.

Video Transcript

Hi Science Teachers,

Welcome to Science Teacher Summer School, Episode 2.

I’m Kent Lui, and something you may not know about me is that I once took harmonica lessons. This was back when I was young, single and had time and was trying to find ways to fill that time and meet people. It was fun, and I remember how to bend notes on a harmonica, which is pretty cool. Now, let’s get to work.

What’s the science skill you want your students to have learned after leaving your science class? For me, it’s knowing how to formulate and communicate a good scientific conclusion or argument. It sounds simple – but requires a whole bunch of other skills like analyzing data and connecting textbook knowledge to real contexts. Also, it’s not something that’s really taught in science textbooks – many textbook labs, for example, just have a list of discussion questions that teachers automatically assign to students at the end of each lab.

So, a few years back, I thought, there’s got to be a better way for students to reflect, write, and discuss their conclusions in their labs.

The solution: I’ve been using a structure known as CER, which stands for Claim, Evidence, and Reasoning, which has been awesome.

A claim is a conclusion or argument I have come up with. Evidence is the data that supports that conclusion. And, reasoning is the scientific explanation for that conclusion.

Let’s consider this textbook lab activity, where students explore what happens to the current when the lamp is switched out for lamps of increasing voltages. In other words, we want to observe the effect that higher voltage lamps have on a circuit’s current.

What I do in my classroom is have students write out CER statements. A CER statement for this lab could sound like this:

When lamps of increasing voltages are connected to a circuit, then the current will decrease. According to our results, when 6V, 12V, 24V, and 36V bulbs were connected one-at-a-time to a circuit, we measured a current of 2A, 1A, 0.5A, and 0.33A respectively. One explanation for this result is that bulbs with larger voltages have larger resistances, and larger resistances prevent the flow of charge through a circuit, which results in a lower current.

Consider the benefits of getting students to write CER statements.

• Students have to analyze and make connections between what they know and what they are observing.
• There’s less plagiarism because it’s not so much about getting an answer as it is about communicating what they found out and how they know it to be true.

Now, perhaps you’re wondering how you can get started. One thing I do with my students at the beginning of the year is a CER activity that has the students learn a little bit about me and practice writing CER statements too. In this activity, I show students things I have brought from home – like… – and then I have students write a CER statement about me. I give them these prompts to help them.

• Claim: What is something you can conclude about Mr. Lui’s personality?
• Evidence: What evidence supports your conclusion?
• Reasoning: What is an explanation as to why Mr. Lui has this personality trait?

For more help getting started with CER, I’m also coming out with an e-book that will provide a collection of notes, worksheets, prompts, and lab activities students can do to practice analyzing data, making connections, and coming up with conclusions.

That’s all the time we have for this episode. Join me next time, when I’ll be talking about how to answer that question we all ask students at the beginning of the year: what is science? You don’t want to miss it.

See you again soon. And, remember to science everywhere everyday.

Resources

Handout(s): 04 – CER Infographics, REAL SC – CER Skill Builder

Our resources are free. We aren’t collecting emails for our resources. However, it would help us out if you liked us on our Facebook page and subscribed to our Youtube Channel. Thanks!