This class runs in two periods and they do not do the same lesson on the same day. You are reading the Period 6A-7B calendar, the one with John Carroll bioethics on Mondays.
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
- Submit this on the class form named on this page. The form requires the student's district Microsoft sign-in. The thank-you page is the submission receipt. A physical handoff counts only when the day page names that route. Doing the activity in myPLTW does not count as submitted.
You get two school days for every day you were absent, so this deadline moves with you.
If the form offers you a saved draft, choose New draft. If the Assignment box comes up empty, type it exactly: Ethics of testing
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
PBS Unit 1 is one case, not twenty topics. A woman was found dead at home, and you are the team that has to work out how she died. You get the evidence in pieces, in the order a real investigation would get it, and you are not told the answer at any point.
Before you run anything, you argue what a laboratory should be allowed to test a sample for. That argument sets the limit you have to respect for the rest of the case.
- Activity 1.1.4 Blood Evidence
Look this up in myPLTW to check you are in the right place.
What you cannot claim in this case, on any day
- A physiological chart records breathing and heart rate. It does not measure lying, and nothing in this unit produces a deception call.
- Microscopic hair comparison can support consistency or support exclusion. It cannot identify a person.
- A fingerprint pattern class can narrow a field or exclude a person. By itself it cannot name a source, and it never says when or why a finger touched something.
- A scheduled event is not proof that a person was there. Time of death is not established by the early evidence.
- Repeating a measurement reduces random error. It does not remove a calibration offset, a shared bias, contamination, or a weak method.
Where the case record itself lives: the case file, the source packet and the timeline are PLTW materials and are handed out on paper in class. They are not posted here.
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.
From Scene to Lab: designing evidence tests and meeting 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: In myPLTW, open Lesson 1.1 Investigating the Scene and go to Activity 1.1.4 Blood Evidence. Read the whole activity before you pick a side in today's debate.
Mark Activity 1.1.4 Blood Evidence started 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 Activity 1.1.4 Blood Evidence started.
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. Submit this on the class form named on this page. The form requires the student's district Microsoft sign-in. The thank-you page is the submission receipt. A physical handoff counts only when the day page names that route. Doing the activity in myPLTW does not count as submitted.
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.
From Scene to Lab: designing evidence tests and meeting biomolecules · Ethics of testing
In myPLTW, open Lesson 1.1 Investigating the Scene and go to Activity 1.1.4 Blood Evidence. Read the whole activity before you pick a side in today's debate.
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.
Submit this on the class form named on this page. The form requires the student's district Microsoft sign-in. The thank-you page is the submission receipt. A physical handoff counts only when the day page names that route. Doing the activity in myPLTW does not count as submitted. 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 form. It must say For students at the top: if it says For parents and guardians, press Back and pick I am the student.
- 2If it offers you a saved draft, choose New draft: an old draft brings back the old assignment.
- 3Sign in with your district Microsoft account, not a personal one.
- 4Check the Assignment box says today's assignment from this page, then pick your period and type your student ID, all nine digits.
- 5Attach your file and press Submit. The thank-you page is your receipt.
Submit this on the class form named on this page. The form requires the student's district Microsoft sign-in. The thank-you page is the submission receipt. A physical handoff counts only when the day page names that route. Doing the activity in myPLTW does not count as submitted. Principles of Biomedical Technology (Principles of Biomedical Science) › From Scene to Lab: designing evidence tests and meeting biomolecules › CERTurn it in
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 review board sorts scientific evidence, stakeholder needs, possible benefits, possible burdens, and uncertainty before choosing a policy.
- Which statements are scientific evidence?
- Which statements express a value or priority?
- Who receives the benefit and who carries the burden?
Use science to estimate consequences, then state the value judgment and tradeoff that determine the decision.
A review-board model organizes reasoning but does not make one ethical principle automatically outweigh every other principle.
- • Evidence cards map to source-backed findings.
- • Stakeholder cards map to affected people and priorities.
- • The recommendation maps to an explicit tradeoff with a named uncertainty.
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: Use the labels and arrows in F1 to identify the relationship that supports Ethics of testing.
- Observe or measure the relevant feature in ethics of testing.
- Organize the observation with a stable evidence ID.
- Apply this rule: Use science to estimate consequences, then state the value judgment and tradeoff that determine the decision.
- 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.
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.
A defensible biomedical decision separates scientific evidence from value judgments, identifies who may benefit or be burdened, and states the uncertainty and tradeoffs that remain.
Limit: Scientific evidence can inform the options and likely consequences, but it cannot choose a single value-neutral answer.
Use science to estimate consequences, then state the value judgment and tradeoff that determine the decision.
Limit: A review-board model organizes reasoning but does not make one ethical principle automatically outweigh every other principle.
You can weigh costs and benefits of testing scope.
Limit: E3 defines the classroom product or success criterion. It is not independent scientific evidence and cannot justify a clinical or causal claim.
PLTW-PBT@P67-2026-09-15 · Simulated classroom evidence scenario
Your role: biomedical team member
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: Today's evidence supports a classroom claim about ethics of testing. It cannot prove causation, diagnose a real patient, or justify action outside this room.
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: A defensible biomedical decision separates scientific evidence from value judgments, identifies who may benefit or be burdened, and states the uncertainty and tradeoffs that remain.
- • E2: Use science to estimate consequences, then state the value judgment and tradeoff that determine the decision.
- • E3: You 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. Use the labels and arrows to identify the decision-relevant relationship. 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.
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: Today's evidence supports a classroom claim about ethics of testing. It cannot prove causation, diagnose a real patient, or justify action outside this room.
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.
Go further and get help▸
Run this before you touch the bench. It is built from the real lab procedure, so the decisions you make here are the ones you will make with the equipment in your hands. This lesson has more than one, and they cover different skills.
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. Submit this on the class form named on this page. The form requires the student's district Microsoft sign-in. The thank-you page is the submission receipt. A physical handoff counts only when the day page names that route. Doing the activity in myPLTW does not count as submitted.
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 through the one route named under Submit here and confirmed by the form receipt or the named physical handoff. Not in Schoology: that is where the report-card grade appears later.