Write the report CER
Tue, Oct 6, 2026 · Week 7 · Principles of Biomedical Technology (Principles of Biomedical Science)
Today's goal: Write a full investigative CER report integrating all evidence and acknowledging limitations.
This is a model of the work you should turn in today. Use it to check your own: match the structure and the level of detail, do not copy it. Your data and wording should be your own.
Parallel case: A sudden fish die-off in a neighborhood pond. A student team investigated why hundreds of fish died overnight, pulling evidence from four independent streams.
Claim: The most likely cause of the fish die-off is oxygen depletion triggered by an algae bloom, not direct chemical poisoning.
Evidence by stream: Field, a dissolved-oxygen meter read far below the level fish need to survive at dawn. Lab, water samples showed nitrate and phosphate concentrations high enough to feed a large algae bloom. Biological, a thick mat of decaying algae covered the surface, and decay consumes oxygen. Records, the weather log showed several hot, still, cloudy days with no wind to mix the water.
Reasoning (convergence): These four independent streams point to the same explanation. Low oxygen, bloom-feeding nutrients, decaying algae, and calm warm weather each describe one part of the same chain, and when separate methods agree on one story the conclusion is strong.
Conflict resolution: One water test flagged a trace of a lawn chemical, which hinted at poisoning instead. I resolved this by trusting the repeated oxygen readings and the visible algae mat over a single trace measurement that was near the detection limit.
Limitations: 1) I did not test the water on the days before the die-off, so I am inferring the bloom timeline rather than observing it directly. 2) Oxygen and nutrient data show a strong pattern but cannot by themselves rule out every other stressor, so the conclusion stays a reasonable-certainty finding, not a certainty.
This model shows the level of evidence and organization needed to complete: A complete investigative report in CER form for a parallel scenario: a cause claim, one piece of evidence from each of four streams, a convergence paragraph, a conflict-resolution sentence, and at least two limitations. Structure mirrors the report students must write, but the case is different so it guides without revealing today's answer.
- Write one defensible claim.
- Choose specific evidence that supports the claim.
- Explain the scientific rule that connects the evidence to the claim.
Keep the structure. Replace the question, facts, measurements, and evidence. Then recheck units, vocabulary, and whether the conclusion goes beyond the evidence.
Turn in: Daily Evidence Sheet, Day 18, every Part complete. Submit one PDF of your Daily Evidence Sheet to Wk7 D18 · Case Closed (PLTW 1.2.6).
Go to Schoology to turn this in.
Submit one PDF. Schoology attaches your name to your upload; on the page itself, write your period and code. Name the file: FirstName LastName - Assignment Title - YYYY-MM-DD.pdf.
Open Schoology PDF upload helpIf you cannot get in, see Mr. Mendoza. Do not skip the work.
Claim ceiling: Today's evidence supports a classroom claim about write the report CER. It cannot prove causation, diagnose a real patient, or justify action outside this room.
One exam-style question that uses exactly what you practiced today. Try it before you reveal the answer, then read why each choice is right or wrong.
Tap an answer to see the full explanation. Nothing is recorded or graded.
It builds this reusable test skill: Structuring a CER report that integrates streams and acknowledges limits.
- Name the concept or data pattern being tested.
- Cross out choices that violate that rule or the evidence.
- Justify the best remaining choice before checking the answer.