Coating ratio CER
This page has four parts, in the order you use them. Part 1 is what you need to know. Part 2 says what to do, in plain English. Part 3 shows the work done once on a case that is not yours. Part 4 is your own work and where to turn it in.
Open your materials, follow the steps, then turn in your work.
Design your own ratio trial, then write a CER recommending a coating ratio against the five-to-six-minute window.
Check you have the right sheet: the top of it prints today's portal day, Coating ratio CER. The PLTW activity itself is in myPLTW and is not posted here.
Optional: listen or watch a unit review▸
Part 1 of 4 · Background and definitions▸
💡 Big idea: This is the first task in the course where better is not more: a coating that opens at three minutes fails exactly as hard as one that opens at nine.
- • A coating ratio CER claim names one ratio and says whether its averaged separation time falls inside the five-to-six-minute window.
- • Trial data is the evidence: the average time for each ratio you tested and the spread between its repeats both belong in the evidence section.
- • A test-data limitation says why a timed run on a coverslip might not match a real tablet in a real gut.
An interval you skipped is data you cannot get back, so the discipline of the interval is what makes the run usable.
This is the first task in the course where better is not more: a coating that opens at three minutes fails exactly as hard as one that opens at nine.
Driving question: Design your own ratio trial, then write a CER recommending a coating ratio against the five-to-six-minute window.
What you already know: An interval you skipped is data you cannot get back, so the discipline of the interval is what makes the run usable.
New idea: This is the first task in the course where better is not more: a coating that opens at three minutes fails exactly as hard as one that opens at nine.
Visual or model: No figure is attached to this lesson. The readings, the worked example and E1 to E3 carry the evidence.
- Observe or measure the relevant feature in coating ratio CER.
- Organize the observation with a stable evidence ID.
- Apply this rule: A design improves when evidence is compared with explicit criteria and constraints.
- Choose the option the evidence supports and state the limit of the conclusion.
Real biomedical example: Today the biomedical team uses Coating ratio CER to make a bounded evidence decision. A classroom , , presentation, or does not establish clinical , effectiveness, manufacturing quality, or regulatory clearance.
What the evidence supports: E1 to E3 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.
- • : The repeating cycle engineers work in: define the problem, set criteria and constraints, generate options, choose one on evidence, build it, test it, and improve it. It is a loop, so a failed test sends you back a stage rather than ending the project.
- • criterion: A clear, agreed-upon standard or rule used to judge, compare, or decide between options.
- • constraint: A limit or requirement that a design must work within, such as a budget, available time, materials, or rules.
- • : An early working model built in order to be tested, not to be sold. Its job is to answer one question about the design, so it is allowed to be rough everywhere that question does not reach.
- • : A written outline of what will be tested, how, and what counts as success, used to guide an experiment or product check.
- • iteration: One repeated cycle of building, testing, and improving, where each pass refines the design or result based on what the last pass revealed.
Use it now: Choose one decision option. Cite E1 and E3, then explain how the rule connects the evidence to your choice. This is thinking practice for the one turn-in named under Turn in, not a second submission.
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 biomedical design advances when test evidence is compared with explicit user needs, criteria, constraints, risks, and failure modes, then used to justify a documented revision.
Limit: A classroom , , presentation, or does not establish clinical , effectiveness, manufacturing quality, or regulatory clearance.
A design improves when evidence is compared with explicit criteria and constraints.
Limit: Biomedical designs also require , ethics, and biological validation beyond a physical test.
Change one variable at a time so a result can be attributed to the ratio.
Limit: E3 defines the classroom product or success criterion. It is not independent scientific evidence and cannot justify a clinical or causal claim.
Today's decision · Simulated classroom evidence scenario
Your role: biomedical team member
Decision: Your team must decide what the evidence from coating ratio CER supports before submitting the claim-evidence-reasoning response named on today's page.
- • Recommend the ratio whose opening time lands inside the five-to-six-minute window, because earlier and later both miss it.
- • Pick the thickest coating you tested, since a longer opening time always means the coating did its job better.
- • Hold the recommendation until a second ratio is tested, because one ratio cannot show which side of the window it misses.
Response: State one choice, cite at least two evidence IDs, explain the rule that connects them, and add one limitation. Use it inside the one turn-in named under Turn in; it is not a separate submission.
Claim ceiling: Today's evidence supports a classroom claim about coating ratio CER. 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 coating ratio CER supports before submitting the claim-evidence-reasoning response named on today's page.
Context: Today the biomedical team uses Coating ratio CER to make a bounded evidence decision. A classroom , , presentation, or does not establish clinical , effectiveness, manufacturing quality, or regulatory clearance.
- • T1: State the target precisely: intact through the stomach phase, then fully separated from the coverslip between five and six minutes.
- • T2: Choose which polymer ratios you will test and how many, and write down why.
- • T3: Write your of fully separated before you run anything, and how you will time it.
- • T4: Decide whether you will repeat each ratio, and how many times.
- • T5: Run the trials and record on the data sheet.
- • T6: Write the CER: your recommended ratio, the data that supports it, and the reasoning that connects them.
- • E1: A biomedical design advances when test evidence is compared with explicit user needs, criteria, constraints, risks, and failure modes, then used to justify a documented revision.
- • E2: A design improves when evidence is compared with explicit criteria and constraints.
- • E3: Change one variable at a time so a result can be attributed to the ratio.
Measurements: Use only the measurements, units, graph, or counts supplied in today's task. No additional patient measurement is implied.
Uncertainty: This is a composite classroom scenario. Missing history, measurements, or confirmation tests remain unknown and limit the conclusion.
- • The solution must address the stated need in coating ratio CER.
- • 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.
- Which version or option did you test?
- Which requirement did it meet or miss?
- Which evidence shows that, and what did it say?
- What did you change?
- Why did you change it?
- Who is this for, and what do they need?
- What must it do, and what limits you?
- Which option did you choose, and what evidence backs it?
- What did you test, and what happened?
- What did you change, and why?
Students often think a polished answer about coating ratio CER is trustworthy even when its evidence source, comparison, or limitation is missing. The trap: Presentation quality cannot raise the evidence level. A classroom , , presentation, or does not establish clinical , effectiveness, manufacturing quality, or regulatory clearance.
- 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 Coating ratio CER. 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.
Part 2 of 4 · Directions in plain English▸
2.1 Open your materials
2.2 Start the work
State the target precisely: intact through the stomach phase, then fully separated from the coverslip between five and six minutes.
Show all 6 required steps
- State the target precisely: intact through the stomach phase, then fully separated from the coverslip between five and six minutes.
- Choose which polymer ratios you will test and how many, and write down why.
- Write your operational definition of fully separated before you run anything, and how you will time it.
- Decide whether you will repeat each ratio, and how many times.
- Run the trials and record on the data sheet.
- Write the CER: your recommended ratio, the data that supports it, and the reasoning that connects them.
Lost your place? Reopen today's Coating ratio CER record. Find the last completed evidence ID, check it against the claim ceiling, and continue with the first unfinished step rather than restarting the whole task.
- 0-8 minPlan the trials: which ratios, how many repeats, and your written definition of fully separated.
- 8-20 minRun the ratio trials and record each time on the data sheet.
- 20-42 minFinish the repeats and average the times for each ratio you tested.
- 42-58 minWrite the claim: the one ratio you recommend, and the averaged times that put it inside or outside the window.
- 58-70 minWrite the reasoning that connects your times to the window, and one test-data limitation.
- 70-80 min: the claim names one ratio, every ratio's times are cited, and the limitation is about the test.
- • Today you design your own ratio trials, run them, and write the argument for one coating ratio.
- • The target is a window, not a race: intact through the stomach phase, then fully separated between five and six minutes.
- • Change one variable at a time, so a difference in timing can be traced to the ratio.
- • Your limitation should say why a timed run on a coverslip might not match a real tablet in a real gut.
PLTW connection and today's work
Open myPLTW and find Lesson 4.1 Designing the Future, Activity 4.1.5 Drug Design Lab Part II, and use its analysis prompts as a writing scaffold.
Today's stopping point: The myPLTW prompts done in the first 10 minutes; full CER submitted before end of period.
PLTW activity titles identify the course connection. If your account will not open, use the posted materials for today and tell Mr. Mendoza. Do not mark an online activity complete unless you completed it.
Use the turn-in directions in Part 4 of this page. Do not create a second submission unless your teacher asks for one.
Show another explanation or a smaller first step
Need help? Choose a starting point
Finish the assigned lab safely before starting extra practice.
Part 3 of 4 · Worked example▸
This is a parallel case, not your own. Read it for the order of the work, then do your own in Part 4.
1. Decision or claim I am testing: ____
2. Evidence ID and exact observation: ____
3. Second evidence ID and exact observation: ____
4. Rule that connects the evidence to my claim: ____
5. Strongest alternative or tradeoff: ____
6. Limitation or missing evidence that controls my confidence: ____
7. Revision I would make if the missing evidence changed: ____
This model shows the level of evidence and organization needed to complete: A blank structure for organizing the assigned response. It contains no claim, ranking, calculation, data interpretation, or recommendation from today's task.
- 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: Submit as one PDF in Schoology.
A bridge is tested against a load limit, cost limit, and user need before revision.
- Which requirement is a criterion?
- Which limit is a constraint?
- What test result should trigger a redesign?
A design improves when evidence is compared with explicit criteria and constraints.
Biomedical designs also require , ethics, and biological validation beyond a physical test.
- • Bridge requirements map to what the device must do for the body.
- • Load results map to the measurements taken from the .
- • Revision maps to the change those measurements justify.
Part 4 of 4 · Your work▸
Check your work before submitting
- Change one variable at a time so a result can be attributed to the ratio.
- Recommend a ratio against the window, not against the fastest time.
Before lab work: read the safety rules
- Goggles on for every trial, including the timing runs.
- The simulated stomach fluid is acidic. Rinse and report any skin contact immediately.
- Shellac preparations are commonly alcohol based. Keep them away from heat and capped between mixes.
- Mix and test a ratio in the same session: cross-linking continues while a coating sits, so yesterday's mix is not today's coating.
- Dispose of every solution in the designated container.
- Wash hands after cleanup.
4.1 Turn in your work
DueCheck the Schoology assignment for this day- Hand in
- CER recommending one coating ratio against the five-to-six-minute window, citing your timed trials for each ratio you tested, with reasoning that connects the data to the window and one test-data limitation.
How to submit and name your file
Submit as one PDF in Schoology.
In Schoology, open your course and the assignment for this lesson. Attach your file, select Submit, and check that it appears in the submission.
PDF upload helpYou get two school days for every day you were absent, so this deadline moves with you.
Today's lesson is in Schoology
Each school day has one lesson page in Schoology that holds everything for the day: the goal, the story so far, every table and data value, the numbered steps, and what to turn in. Open it first and work from it. The other rows for this day, if any, are the score line for a paper quiz or test and the John Carroll debate item; they do not add work. Check Schoology for each deadline.
- Today's Lesson · Tue 12/15 · Wk17 · Stop the Bleed, then triage fifteen emergency room patients(today's lesson page: the goal, the data, the steps, and what to turn in are all on it)
Link will not open? Open Schoology, choose your course and section, and find the title shown above.
- 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.
- SubmittedGo 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. If you cannot get in, see Mr. Mendoza. Do not skip the work.
- Error analysis and method · counts doubleName a specific limit of the method and how it moved your result, and compare what you predicted to what happened. "Human error" does not count; say what about the procedure or instrument caused it.
How this lesson connects
Keep using what you learned last class: An interval you skipped is data you cannot get back, so the discipline of the interval is what makes the run usable. Today: This is the first task in the course where better is not more: a coating that opens at three minutes fails exactly as hard as one that opens at nine.
Practice: try a question, then check your answer▸
Claim ceiling for this check: Today's evidence supports a classroom claim about coating ratio CER. It cannot prove causation, diagnose a real patient, or justify action outside this room.
A student treats one classroom result about coating ratio CER as proof. What must the student add before the conclusion is defensible?
Write an answer and pick a confidence to unlock the key.
Missed class or ready for more?▸
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.
I can name the procedure's purpose and the evidence I will record. I can name today's hazards and the control for each: Shellac preparations are commonly alcohol based. Keep them away from heat and capped between mixes. My data table is ready before materials are handled.
Finish the checklist before you handle any material.
- • Goggles on for every trial, including the timing runs.
- • The simulated stomach fluid is acidic. Rinse and report any skin contact immediately.
- • Shellac preparations are commonly alcohol based. Keep them away from heat and capped between mixes.
- • Mix and test a ratio in the same session: cross-linking continues while a coating sits, so yesterday's mix is not today's coating.
- • Dispose of every solution in the designated container.
- • Wash hands after cleanup.
- 1Before materials are handled, identify the purpose, variables or comparison, controls, measurement units, and stop-work condition.
- 2State the target precisely: intact through the stomach phase, then fully separated from the coverslip between five and six minutes.
- 3Choose which polymer ratios you will test and how many, and write down why.
- 4Write your operational definition of fully separated before you run anything, and how you will time it.
- 5Decide whether you will repeat each ratio, and how many times.
- 6Run the trials and record on the data sheet.
- 7Write the CER: your recommended ratio, the data that supports it, and the reasoning that connects them.
- 8Record each result in the prepared table before interpreting it. Mark missing, repeated, or invalid results truthfully.
- 9Complete the named cleanup and waste route, remove PPE safely, wash hands when required, and confirm the station is ready for the next group.
| Which trial or sample this row is | What you changed on purpose | What you measured, with units | What you saw, before you explain it | Anything that could make this reading wrong |
|---|---|---|---|---|
Before the procedure, predict the result and cite the rule behind the prediction.
After the procedure, compare the result with the prediction and name one limitation or source of uncertainty.
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.
Today is individual work you can do from home: complete the same target above, then submit your CER.
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. If you cannot get in, see Mr. Mendoza. Do not skip the work.
Class still runs. Complete today's work as this page describes (it is self-guided). Need the concept taught without a teacher? Use this authoritative explainer:
PhET: simulations for engineering and physical testingThe optional extra-credit track is open. Complete reserved-unit work from home, including virtual labs, for extra credit. Each item shows its correct submission route.
Open the extra-credit trackSources: slides, readings, and resources▸
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.
Play the cold open at the start of the unit to set the scene. Each recording is AI-generated and simulated (fictional callers, no real people or student data).
Hand-picked readings and interactives for this lesson, from authoritative open organizations and PLTW's own public course outline.
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