Scientific Conclusions

When making scientific conclusions, start with your CLAIM (what you think is happening), back it up with EVIDENCE, what you actually saw, measured, or observed in your experiment), and connect them with REASONING (explain WHY your evidence proves your claim using scientific facts you know).

⭐ Think of it like building a case: your claim is what you're trying to prove, your evidence is the clues you collected, and your reasoning is explaining how those clues prove your point using scientific knowledge!

CER Example and Walkthrough
Use this video to help you understand how to write using the CER process.
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Question 1
Using the CER framework, construct a scientific explanation addressing the following question:

Question 8: CLAIM

What is happening to the water quality of Lake Erie over time?

(1 point)
The water quality of Lake Erie is
decreasing
.
Question 2
Question 9: EVIDENCE.

Using the data table and graph below, provide evidence that will support your claim.

(2 points)
I know this is happening to the water quality in Lake Erie because the
pH
is
increasing
based on the data in Data Table 2.
Question 3
Question 10: REASONING
Explain how the abiotic (non-living) factor (pH, temperature, etc.) you chose in your evidence affects the health of the ecosystem in Lake Erie.

⭐Hints:

Review the graph and data chart and identify what information best supports your claim.
Think about how your chosen abiotic factor affects the health of the aquatic ecosystem
Review what can cause your chosen abiotic factor to get worse

Optional Sentence Starters:
“I know the (ph, surface temperature, size of the dead zone, or water clarity) of Lake Erie was getting (better or worse) because the numbers in the data table were…”
“When the (ph, surface temperature, size of the dead zone, or water clarity) gets worse, it can affect the aquatic ecosystem by…”
“The (ph, surface temperature, size of the dead zone, or water clarity) can negatively affect the aquatic ecosystem because…”

(4 points)

10000 Word Limit
Rubric

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use temperture as the subject

1 answer

Claim:
The water quality of Lake Erie is decreasing.

Evidence:
I know this is happening to the water quality in Lake Erie because the temperature of the water has been increasing over time based on the data in Data Table 2. The rising temperatures can be observed in the recorded data where average water temperatures have consistently exceeded historical norms over the past several years.

Reasoning:
When the surface temperature of Lake Erie increases, it can negatively impact the health of the aquatic ecosystem. Warmer water holds less dissolved oxygen, which is crucial for the survival of fish and other aquatic organisms. As temperature rises, it can lead to harmful algal blooms, which further deplete oxygen levels in the water as they die and decompose, creating "dead zones" where aquatic life cannot survive. Increased water temperatures can also disrupt the growth and reproduction of native species, altering the food web dynamics in the ecosystem. Thus, the rising temperature represents a negative trend in the overall water quality of Lake Erie, supporting the claim that the water quality is decreasing.