Ethics of testing
Do now
Debate whether all biological samples should be tested for everything possible, and defend your stance.
- Hand in
- Written CER (3-5 sentences) arguing whether investigators should test a sample exhaustively or only according to a hypothesis, with sample limitation cited in the reasoning.
- Where
- Turn this in at the drop folder with your district Microsoft sign-in, or hand it to Mr. Mendoza in class. Both count as submitted. Doing the activity in myPLTW does not.
You get two school days for every day you were absent, so this deadline moves with you.
If a bloodstain at a crime scene is the size of a dime and every test consumes some of it, should the lab run every test the sample allows, or only the ones the case theory calls for?
Debate whether all biological samples should be tested for everything possible, and defend your stance.
- • I can weigh costs and benefits of testing scope.
- • I can defend a position with reasoning.
- Name one reason a sample might be impossible to replace once it is used up.
- If you could only run one test on a single drop of blood, how would you decide which test to run?
- 1Read the prompt: Should investigators run every test a sample allows?
- 2List one benefit and one harm of over-testing a limited sample.
- 3Choose a side: test exhaustively vs. test only the hypothesis.
- 4Argue your claim in your group, citing sample limitation as a constraint.
- 5Post a written CER with your position and supporting reasoning.
What did this day actually feel like?
Ethics of testing
ETHICS DAY Today's question: should investigators run every test a sample allows, or only the tests their hypothesis calls for?
It sounds obvious until you learn that samples are finite. Every test consumes a little. Run everything and you might use up the sample before you get to the test that mattered.
I argued for testing exhaustively because you cannot un-miss something. The counterargument was sharper than I expected: testing without a hypothesis is fishing, and if you run enough tests something will come back positive by chance alone. That is a real statistical problem, not a debate trick, and it changed how I think about the word "thorough."
Mr. Mendoza announced at the end that John Carroll is confirmed to start next Monday. He said their philosophy program runs these discussions with students and that our format will not change much, we will just have someone else asking the questions.
AT HOME, THE NIGHT BEFORE THU SEP 17 Biomolecules and design The four biomolecules: carbohydrates, lipids, proteins, nucleic acids. Each one has an indicator test, which is a chemical that changes color when that molecule is present. Benedict's for reducing sugars, iodine for starch, Biuret for protein, Sudan for lipids.
Then experimental design, which is where I got tripped up. Independent variable, dependent variable, controlled variables. I kept mixing up dependent and controlled. The way it finally stuck: the dependent variable is the one I measure, the controlled variables are the ones I refuse to let change. We built a pre-lab design sheet for tomorrow so we walk in knowing what we are doing instead of reading instructions at the bench.
Turned in: pre-lab design sheet → recorded in Class Records
Fiction. There is no such student. The lessons, labs and dates are the real planned course; the student, the classmates and the conversations are invented.
The same day, drawn.
Should you run every test a sample allows? Samples are finite. Every test uses some up.
CLASSMATE
Test without a hypothesis and you are fishing. Run enough tests and something comes back positive by luck.
Fiction. There is no such student. The lessons, labs and dates are the real planned course; the student, the classmates and the conversations are invented.
🛠 Get unstuck · pick your level
🔑 Today's words · 5
Tap a word in the lesson for a plain meaning and one example. Recycled into next week's Do-Now.
Do the work · 80-minute blockfirst 5 min = hook▸
💡 Big idea: A hypothesis constrains which tests are worth running because the sample is finite and every test both consumes it and risks a , so untargeted testing destroys evidence and interpretability at once.
- 0:00Hook: scenario of a limited sample with too many requested tests; what do you cut?
- 0:08Introduce probability concept; brief class discussion
- 0:18Read the ethics prompt; list one benefit and one harm of exhaustive testing
- 0:30Small-group debate: test exhaustively vs. test only the hypothesis; cite sample limitation
- 0:52Individual CER writing: position, evidence, reasoning
- 1:10Share two CERs; connect to Wednesday's lab design choices
- • Imagine a blood sample the size of a pinhead. You can run maybe three tests on it before it is gone. Which three do you pick?
- • Today's ethical question is one that scientists and doctors face every day: should you test for everything just because you can?
- • There is a real cost to over-testing. You can use up a sample that cannot be replaced. And every test has a small probability of returning a , which could send an investigation in the wrong direction.
- • Pick a side and defend it. You will use this reasoning when we design our actual tests on Wednesday.
- • and biomedical samples are often irreplaceable; running unnecessary tests can exhaust a sample and destroy its evidentiary value.
- • A hypothesis constrains which tests are meaningful so that results are interpretable rather than a scatter of unrelated data.
- • Every test carries a probability of false positives; more tests on the same sample increases the chance of a misleading result.
Unit 1.1 to 1.2: Experimental design in evidence testing; transition to autopsy evidence and biomolecules. · Ethics of testing
Day 1 of this lesson. Open this exact section in myPLTW (find it in Clever, Microsoft sign-in), then do the work below.
Do this: Log in to myPLTW and open the Lesson 1.1 Investigating the Scene evidence-testing section. Read the unit overview and toxicology introduction before Tuesday.
Mark the evidence-testing unit overview task complete in myPLTW.
You finished Lesson 1.1 scene work last week. Today starts the evidence and phase of Lesson 1.1. The overview reading should be done by the end of today.
myPLTW screenshot showing the Lesson 1.1 evidence-testing overview task marked complete.
The official PLTW activity stays inside myPLTW. If myPLTW will not open, use F1 and E1-E3 on this page to complete today's local evidence decision, then make up the official activity when access returns. Turn this in at the drop folder with your district Microsoft sign-in, or hand it to Mr. Mendoza in class. Both count as submitted. Doing the activity in myPLTW does not.
Check things off as you work, then submit. This tells Mr. Mendoza how you're doing so he can help the class. It does not replace turning in your producible through the submission route shown below.
Use the code Mr. Mendoza gave you, not your name. Saved on this device.
Unit 1.1 to 1.2: Experimental design in evidence testing; transition to autopsy evidence and biomolecules. · Ethics of testing
Log in to myPLTW and open the Lesson 1.1 Investigating the Scene evidence-testing section. Read the unit overview and toxicology introduction before Tuesday.
You finished Lesson 1.1 scene work last week. Today starts the evidence and phase of Lesson 1.1. The overview reading should be done by the end of today.
This is how Mr. Mendoza sees the class keeping pace with PLTW. Be honest, it only helps if it is accurate.
🎯 Debate whether all biological samples should be tested for everything possible, and defend your stance.
- Read the prompt: Should investigators run every test a sample allows?
- List one benefit and one harm of over-testing a limited sample.
- Choose a side: test exhaustively vs. test only the hypothesis.
- Argue your claim in your group, citing sample limitation as a constraint.
- Post a written CER with your position and supporting reasoning.
CER: Written CER (3-5 sentences) arguing whether investigators should test a sample exhaustively or only according to a hypothesis, with sample limitation cited in the reasoning.
Turn this in at the drop folder with your district Microsoft sign-in, or hand it to Mr. Mendoza in class. Both count as submitted. Doing the activity in myPLTW does not. Use the checklist just below and upload by 11:29 PM for full credit. Absent with an excused absence? You get two school days for every day you were absent, so this deadline moves with you.
| Task | Who |
|---|---|
| Read the prompt: Should investigators run every test a sample allows? | _______ |
| List one benefit and one harm of over-testing a limited sample. | _______ |
| Choose a side: test exhaustively vs. test only the hypothesis. | _______ |
| Argue your claim in your group, citing sample limitation as a constraint. | _______ |
| Post a written CER with your position and supporting reasoning. | _______ |
Working solo? Put your own name in "Who" for every row.
- I can weigh costs and benefits of testing scope.
- I can defend a position with reasoning.
- 1Do thisDebate whether all biological samples should be tested for everything possible, and defend your stance.
- 2Use this resource
- 3Submit thisCER: Written CER (3-5 sentences) arguing whether investigators should test a sample exhaustively or only according to a hypothesis, with sample limitation cited in the reasoning.
- 4Submit it here
- 1Open the drop folder.
- 2Sign in with your district Microsoft account, not a personal one.
- 3Upload the file, named Lastname_Firstname__Assignment Title.
- 4Your own upload panel says Uploaded with a green check: that is your receipt.
Turn this in at the drop folder with your district Microsoft sign-in, or hand it to Mr. Mendoza in class. Both count as submitted. Doing the activity in myPLTW does not. Principles of Biomedical Technology (Principles of Biomedical Science) › Unit 1.1 to 1.2: Experimental design in evidence testing; transition to autopsy evidence and biomolecules. › CEROpen the drop folder
Learn it · deck, reading, and vocabulary▸
The deck carries the prior idea forward, lets you inspect an analogy, maps the rule to biology, and ends with the same evidence decision and exit ticket used on this page.
Generated from this lesson's canonical data with a red-team citation check.
Observations become evidence only when compared to a reference and bounded by their limits, because corroborates a convergent chain rather than proving guilt alone.
A hypothesis constrains which tests are worth running because the sample is finite and every test both consumes it and risks a , so untargeted testing destroys evidence and interpretability at once.
A smoke alarm detects signs of fire but can also react to burnt toast.
- What does the alarm detect?
- What creates a false alarm?
- What evidence is needed before declaring a fire?
A screening signal changes what to investigate next; it does not automatically prove the cause.
Biomedical tests have measured performance and biological sampling limits that a household alarm does not capture.
- • Alarm signal maps to a test result.
- • Burnt toast maps to a .
- • Inspection maps to confirmation or the next test.
Driving question: If a bloodstain at a crime scene is the size of a dime and every test consumes some of it, should the lab run every test the sample allows, or only the ones the case theory calls for?
What you already know: Observations become evidence only when compared to a reference and bounded by their limits, because corroborates a convergent chain rather than proving guilt alone.
New idea: A hypothesis constrains which tests are worth running because the sample is finite and every test both consumes it and risks a , so untargeted testing destroys evidence and interpretability at once.
Visual or model: F1. F1. A lesson illustration or teaching diagram for Ethics of testing. Use it with E1-E3; it is a model or context image, not experimental or patient data. What to notice: Trace the labeled observation or evidence sequence before choosing an explanation.
- Observe or measure the relevant feature in Ethics of testing.
- Organize the observation with a stable evidence ID.
- Apply this rule: A screening signal changes what to investigate next; it does not automatically prove the cause.
- Choose the option the evidence supports and state the limit of the conclusion.
Real biomedical example: If a bloodstain at a crime scene is the size of a dime and every test consumes some of it, should the lab run every test the sample allows, or only the ones the case theory calls for?
What the evidence supports: E1-E3 and F1 support the daily take-home when the response meets the stated success criteria.
What it cannot prove: The package does not support claims beyond this lesson's or any real patient diagnosis.
- • : A molecule produced by living things that carries out life's functions, including carbohydrates, lipids, proteins, and nucleic acids.
- • : A large biological molecule built from smaller units, with the four main classes being carbohydrates, lipids, proteins, and nucleic acids.
- • toxicology: The science of how chemicals and other substances cause harm to living things, including the dose at which they become dangerous.
- • : A group of similar cells working together to perform a shared function, such as muscle, nerve, or .
- • : A careful medical examination of a body after death to find the , study disease, and gather evidence.
- • : The specific injury or disease that directly led to a person dying, such as a heart attack or massive blood loss.
- • : The classification of how a death came about, falling into categories such as natural, accident, suicide, homicide, or undetermined.
Use it now: Choose one decision option. Cite E1 and E3, then explain how the rule connects the evidence to your choice.
Go further, optional: The source links below are optional enrichment. Every fact required for today's local evidence decision appears in this lesson package.
and biomedical samples are often irreplaceable; running unnecessary tests can exhaust a sample and destroy its evidentiary value.
Limit: E1 supplies context or an observation; it does not by itself establish the explanation.
A hypothesis constrains which tests are worth running because the sample is finite and every test both consumes it and risks a , so untargeted testing destroys evidence and interpretability at once.
Limit: E2 is a teaching statement or comparison and must be checked against the task evidence.
I can weigh costs and benefits of testing scope.
Limit: E3 supports only the result or product criterion named here; it cannot justify a broader clinical or causal claim.
PLTW-PBT-2026-09-15 · Simulated classroom evidence scenario
Your role: biomedical investigator
Decision: Your team must decide what the evidence from Ethics of testing supports before submitting the claim-evidence-reasoning response named on the lesson page.
- • Choose the strongest supported explanation.
- • Choose the next evidence to collect.
- • Hold the decision because the evidence is insufficient.
Response: State one choice, cite at least two evidence IDs, explain the rule that connects them, and add one limitation. Submit it as the claim-evidence-reasoning response.
Claim ceiling: The supplied lesson evidence can support an observation, pattern, classroom mechanism, or next-step decision about Ethics of testing. It cannot by itself prove causation, establish a real clinical diagnosis, or justify action outside this classroom task.
Reason for review: Your team must decide what the evidence from Ethics of testing supports before submitting the claim-evidence-reasoning response named on the lesson page.
Context: A limited sample forces you to choose your tests before you run them, because a hypothesis tells you which results will actually mean something.
- • T1: Read the prompt: Should investigators run every test a sample allows?
- • T2: List one benefit and one harm of over-testing a limited sample.
- • T3: Choose a side: test exhaustively vs. test only the hypothesis.
- • T4: Argue your claim in your group, citing sample limitation as a constraint.
- • T5: Post a written CER with your position and supporting reasoning.
- • E1: and biomedical samples are often irreplaceable; running unnecessary tests can exhaust a sample and destroy its evidentiary value.
- • E2: A hypothesis constrains which tests are worth running because the sample is finite and every test both consumes it and risks a , so untargeted testing destroys evidence and interpretability at once.
- • E3: I can weigh costs and benefits of testing scope.
Measurements: Use only the measurements, units, graph, or counts supplied in today's task. No additional patient measurement is implied.
Figure finding: Teaching diagram for Ethics of testing. Trace the labeled observation or evidence sequence before choosing an explanation. This is a teaching model, not patient or experimental data.
Uncertainty: This is a composite classroom scenario. Missing history, measurements, or confirmation tests remain unknown and limit the conclusion.
Mean = sum of values / number of values. Median = middle ordered value. Range = maximum - minimum.
For 2, 4, 4, and 10: mean = 20 / 4 = 5, median = 4, and range = 10 - 2 = 8.
Mean, median, and range keep the measurement unit. Order the values before finding the median.
Calculate the requested summary for today's supplied values, then write what it reveals and what it hides.
- • The solution must address the stated need in Ethics of testing.
- • The decision must be supported by E1-E3.
- • The final product must make the success criteria visible.
- • Complete the work inside the 80-minute block.
- • Use only supplied or teacher-approved materials and evidence.
- • Do not trade , accessibility, or privacy for speed.
- • and evidence quality: must pass before scoring other criteria.
- • User need and effectiveness: highest scored criterion.
- • Time, cost, and ease of use: compare only after and effectiveness pass.
Test evidence: For each option, record the E1-E3 result that supports or fails each criterion. Do not assign a score without a named observation.
- Version or option tested
- Criterion met or missed
- Evidence ID and result
- Revision made
- Reason for the revision
- Need and user
- Criteria and constraints
- Chosen option and evidence
- Test result
- Revision and reason
Students often think Students assume more testing always means more truth, so running every possible test on a sample must give the most complete and reliable answer.. The trap: Running every test is a trap because each test consumes irreplaceable sample and carries its own false-positive rate, so piling on tests can exhaust the evidence and stack up misleading results instead of clarifying the case.
Parallel case: A hospital lab has a single small tube of a patient's leftover blood after the ordered test is complete. A researcher asks to use it. Should the lab run every research assay the tube can support, or only the assays the study's question calls for?\n\nClaim: The lab should run only the assays the research question calls for, not every assay the leftover tube can support.\nEvidence: The leftover blood is a fixed, single-use amount, and each assay consumes part of it; running every possible assay can exhaust the tube before the study's own question is measured. Consent for leftover samples is also usually written for a stated purpose, so tests outside that purpose may fall outside what the patient agreed to.\nReasoning: A defined research question sets which assays are meaningful, so the results can be interpreted together instead of becoming a pile of unrelated numbers. Each extra assay on the same tube also adds another chance of a false positive, so broader testing raises the odds of a misleading finding that no one planned to act on. Limiting testing to the question protects the sample, keeps the findings interpretable, and keeps the work inside the consent the patient gave.
This model shows the level of evidence and organization needed to complete: A claim-evidence-reasoning paragraph, modeled on a parallel scenario, arguing whether the scope of testing on a limited biological sample should be set by a specific question or run as broadly as the sample allows.
- 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.
Also due today: Post your CER to the discussion board or hand in the written copy before leaving.
- CER:
- Claim, Evidence, Reasoning: make a claim, back it with evidence, explain your reasoning.
- SOP:
- Standard Operating Procedure, the exact steps to follow (especially in a lab).
- Tracker:
- Your PLTW progress log where you record completed evidence.
- myPLTW:
- The PLTW course site where you do the online activities. Find it in Clever with your Microsoft sign-in, right next to Schoology.
Tap the speaker to hear a term. Add two of these to your notebook glossary with a definition and an example in your own words.
Pick just 2 or 3 words from today and make them yours: write what each one means in your own words, name the context clue or evidence that helped, then give one example from what you actually did in Ethics of testing. Try your own words first; the glossary is there if you get stuck. This is voluntary and counts as extra credit, so keep it short.
Saved on this device. Show Mr. Mendoza or add these to your notebook glossary to claim the extra credit.
Hand-picked readings and interactives for this lesson, from authoritative open organizations and PLTW's own public course outline.
Check yourself · commit, then reveal▸
Claim ceiling for this check: The supplied lesson evidence can support an observation, pattern, classroom mechanism, or next-step decision about Ethics of testing. It cannot by itself prove causation, establish a real clinical diagnosis, or justify action outside this classroom task.
A lab has one tiny sample and two possible tests. Why can't they just run both to be safe?
Write an answer and pick a confidence to unlock the key.
Fast retrieval with instant answers, not the commit-then-reveal check above. Try each from memory first: write what you remember about the earlier units, then check yourself here.
Go further and get help▸
What today's skills lead to. These are real health-science careers this course builds toward. Tap one to see, on the US Department of Labor's O*NET site, what the job actually involves, what it pays, and how fast it is growing.
Watch the recorded testing-ethics prompt and post a written CER on whether exhaustive sample testing is justified.
John Carroll Philosophy for ChildrenThen submit your CER. Turn this in at the drop folder with your district Microsoft sign-in, or hand it to Mr. Mendoza in class. Both count as submitted. Doing the activity in myPLTW does not.
Class still runs. Complete the online activity above (it's self-guided). Need the concept taught without a teacher? Use this authoritative explainer:
Khan Academy: macromolecules- CompleteEvery required part of the artifact is present, nothing left blank.
- AccurateThe science and the data are correct and match the evidence.
- Scientific reasoningYou explain your claim with evidence and reasoning (CER), not just an answer.
- Professional communicationClear, organized, labeled, and written the way a clinician or scientist would.
- SubmittedTurned in the right way, on the class site or handed to Mr. Mendoza in class, and confirmed. Not in Schoology: that is where the report-card grade appears later.