Claim, Evidence, Reasoning

CER is a powerful framework used in science education to help students develop critical thinking and analytical skills. It stands for Claim, Evidence, Reasoning, and it’s a way to structure scientific arguments or explanations.


Here’s how it works:

  1. Claim: This is a statement or answer to a scientific question. It’s what you think or what you’ve found out. For example, “Plants grow faster in sunlight.”

  2. Evidence: These are the facts, data, or observations that support your claim. It’s important that evidence is gathered through experiments, observations, or research. For the above claim, evidence could be, “In a two-week experiment, plants in sunlight grew three inches, while those in the dark grew only one inch.”

  3. Reasoning: This links your evidence to your claim. It’s the scientific principle or understanding that explains why your evidence supports your claim. For our example, the reasoning might be, “Photosynthesis, which is necessary for plant growth, requires sunlight. The plants in the sunlight had more opportunity for photosynthesis, hence they grew more.”

Why Use CER?

  • Develops Critical Thinking: CER helps students think more deeply about how they draw conclusions from data.
  • Improves Communication: Students learn how to construct and articulate logical, evidence-based arguments.
  • Encourages Scientific Inquiry: CER mirrors the process scientists use, fostering a better understanding of scientific methods.

Virtual Science Teachers is developing a series of simple and versatile CER resources, suitable for use with our interactives or independently. We’re excited to expand this collection and welcome your suggestions. Share your ideas at admin@virtualscienceteachers.org – we’d love to hear from you!

Photosynthesis CER

Photosynthesis CER

May be used with VST interactive.

CER: Climate Change Rising Sea Levels

Climate Change: Rising Sea Levels CER

May be used with VST interactive.

Why Does Ice Float?

Why Does Ice Float? CER

May be used with VST interactive.

Investigate how sea levels are impacted by ice melting in two scenarios: ice from land sources like glaciers, and ice already floating in the sea.

NASA Melting Ice Activity: New Tab

Ocean Acidification CER

Ocean Acidification

May be used with VST interactive.