Clue 1: Orient yourself
Who knows the lane before assignment?
Use the labels and the picture's left-to-right, near-to-far, or before-and-after order. Name only what you can point to.
The question
How do you make a fair comparison between two treatments for children?
Why it matters: Clinical recommendations affect real children and families. Fair comparisons, bias control, ethical limits, and honest uncertainty keep a promising result from becoming a harmful claim. Today you practice the professional reasoning behind that work: Fair treatment trials require equipoise, concealed randomization, unbiased outcome assessment, and analysis by assigned group.
On your WebXam
Recognizing why intention-to-treat preserves randomization
For life
To find the cause, change one thing and watch what changes.
Principle: Same look, different cause
Five principles we return to
Having it is not using it
Same instructions, different switches
Same look, different cause
Change one thing and watch
Boss or doorman?
Decides the result or only allows it
Held down, not gone
Remove the brake and it returns
Many roads, one ending
One result can begin many ways
Try the everyday version first
A fair race uses concealed lanes, blinded judges, and every assigned runner
A fair race keeps lane assignment hidden, prevents judges from favoring a runner, and counts everyone assigned. These steps reduce several kinds of bias.
Do not jump to the biology yet. Treat the picture as a small system. Track its parts, follow one change at a time, and keep more than one explanation open until the picture supplies a way to separate them.
Clue 2: Trace one change
What is hidden from judges?
Follow one object, stage, or path. Point to the first place where the situation changes instead of jumping to the ending.
Clue 3: Keep the cause open
Why keep runners in their assigned lane during analysis?
List more than one explanation that still fits. Name the extra observation that would help you separate those possibilities.
Now inspect the illustration
Work from the visible evidence. A useful answer names the part of the picture that supports it and leaves unknown causes open.
- 1Who knows the lane before assignment?
- 2What is hidden from judges?
- 3Why keep runners in their assigned lane during analysis?
Tier 1 check
Finish with the everyday model
Use the everyday picture to answer today's question in plain words: How do you make a fair comparison between two treatments for children?
You can complete today's required check without opening the technical details below.
Ready for the real names? Optional tier 2
Technical rules and limits
Rule 1: Randomize only between acceptable options under genuine uncertainty.
Rule 2: Conceal assignment and blind outcome assessment when feasible.
Rule 3: Use intention-to-treat to preserve the assigned comparison.
Where the analogy stops: Clinical trials cannot blind every participant or clinician, and patient care must continue throughout the study.
Carry the previous idea forward
Loss plus targeted rescue strengthens causation when the rescue is specific, verified, and compared with controls.
Today's technical takeaway
Fair treatment trials require equipoise, concealed randomization, unbiased outcome assessment, and analysis by assigned group.
Now map the same rules onto biology
Design a fair comparison of two accepted palate-repair timings
Concealed lane draw
Allocation concealment and randomization
Coded judges
Blinded outcome assessment
Assigned-runner roster
Intention-to-treat analysis
Educational illustration, not a clinical photograph or a patient-specific study plan. Use the supplied evidence cards and claim ceiling.
Mateo's case file: evidence supplied in this lesson
EXP13-E1
Both timings are accepted options and experts remain uncertain about their balance of outcomes.
Why it matters: Clinical equipoise can support randomization.
EXP13-E2
A central system reveals assignment only after an eligible infant is enrolled.
Why it matters: Allocation concealment reduces selection manipulation.
EXP13-E3
Speech assessors receive coded recordings and analysis keeps participants in assigned groups.
Why it matters: Blinding and intention-to-treat protect the comparison.
Make the clinical decision
You are the clinical-trial methods chair.
A surgeon wants to choose timing after seeing the next assignment and remove crossovers from analysis.
AUse concealed randomization, coded assessment, and intention-to-treat.
BLet the recruiter predict and change assignments.
CAnalyze only participants who perfectly followed the schedule.
Choose the fair-trial plan and explain the threat controlled by each safeguard.
Evidence required
EXP13-E1 + EXP13-E2 Claim ceiling
You may design the comparison when both options are acceptable. You may not randomize repair versus knowingly harmful no repair.Go deeper Optional tier 3
Everything required for today is above. Open these only if you want the explainer, source trail, or download files.
The everyday model and Tier 1 check are the complete required path for this lesson.
Use these checks to keep your place. They are not turned in through the portal.
Check off as you finish
- Worked through the everyday picture and answered its three questions.
- Completed the Tier 1 check in plain words.
Turn in: Experimental Design lesson 13: The Fairest Test: How to Compare Two Treatments in Real Children
Go to Schoology to turn this in.
Submit one PDF. Put your first and last name in the document header. 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.
Optional legacy technical materials Open only if you want the original notes, vocabulary, artifact, and CER work
Before this page, you should know
- A removes a gene to see what fails; by itself it shows the gene is needed but does not prove the gene, and nothing else, caused the defect.
- A deletes a possible backup gene (here Ezh1) to rule out that the backup, not your gene, explains the result; losing Ezh1 alone did nothing to the .
Today's new idea is only
Randomization, , and intention-to-treat analysis make a two-treatment comparison fair, and equipoise is what makes randomizing ethical in the first place.
Goal: Explain how randomization, , and intention-to-treat make a two-treatment comparison fair, and identify each, plus equipoise, in a study description.
Know by the end
- A assigns patients to treatments by a chance process, and it is the strongest design for a question about which treatment causes a better outcome.
- Randomization spreads every trait, even traits never measured, roughly evenly across groups, so any difference in outcome is believably due to the treatment.
- keeps the outcome assessor unaware of group assignment; a surgeon cannot be blinded, so TOPS blinded the central speech assessors who scored children at age 5.
- Intention-to-treat analyzes each patient in the group they were assigned to, even if their treatment changed, which protects the balance randomization built; equipoise (genuine uncertainty) is required before it is ethical to randomize.
1
Randomization and blinding
Model start: A compares treatments by assigning patients to groups at random; it is the strongest design for a which-treatment-is-better question.
- Randomization means a chance process, not a person's judgment, decides who gets which treatment, so over many patients every trait spreads roughly ____ (evenly / unevenly) across groups.
- means keeping someone unaware of the assignment; when the person measuring the outcome does not know the group, their expectations cannot ____ (color / sharpen) the score.
- TOPS could not blind the ____, who always knows what they did, so it blinded the central speech assessors instead.
2
Intention-to-treat and equipoise
- Intention-to-treat means analyzing each patient in the group they were ____ to, even if their treatment later changed, which protects the balance randomization built.
- Equipoise means it is only fair to randomize when the expert community genuinely does not ____ which option is better.
- A sham (fake) surgery is generally unacceptable in children, so a surgical RCT compares two ____ treatments, never treatment versus a pretend operation.
Everything you need for today is on this page. These links are optional.
What to read
Read the short plain-language explanation written for this lesson. Plain-language explainer for this lesson
Why this source matters
This explanation gives you the background for today's idea without making you decode a research paper: Randomization, , and intention-to-treat analysis make a two-treatment comparison fair, and equipoise is what makes randomizing ethical in the first place.
Words to unlock first
randomized controlled trialrandomizationblindingintention-to-treatequipoise
Reading moves
- Skim the title and abstract first to get the gist.
- Circle the one sentence that states the main claim.
- Box the evidence the authors give for that claim.
- Mark one sentence that confuses you, and move on.
Stop point
Stop after the final 'Use it now' section. The research citations are available separately for advanced readers.
Your output
Write one claim-evidence sentence: state the main idea, then name the example or evidence that supports it.
Where this fits
Tested on (Ohio WebXam)
Genetics of Disease · 072130
PLTW lesson
MI · Experimental Design domain · Randomized controlled trial design; randomization, blinding, intention-to-treat, equipoise
WebXam domain
Molecular and Genetic Technology
Evidence to produce
A colleague proposes: to find the better cleft palate surgery, let each family pick Surgery A or B, then compare the groups after five years. As PI, redesign this into a fair trial. (1) Replace the family-picks step with one sentence describing randomization. (2) Add one sentence describing who you would blind and why the surgeon cannot be blinded. (3) State the intention-to-treat rule for a child assigned A whose family later switched to B. (4) Name the one condition (equipoise) that must be true before it is even ethical to randomize.
Lab / skill
Biomedical Innovations (BI) · AP Biology
Everything required for today's decision is already in the case file and plain-language explainer. The links below are original papers and database records for teachers and advanced readers, not assigned student reading.
- NEJM. Timing of Primary Surgery for Cleft Palate (TOPS), 2023.
- CONSORT 2025. Updated reporting guidance for randomized trials.
- Gamble et al. 2023, Timing of Primary Surgery for Cleft Palate (TOPS trial, NEJM)
- Ozawa et al. 2020, Surgical technique and timing in UCLP, a randomized clinical trial (Orthod Craniofac Res)
- Claim: A gives a (more / less) trustworthy answer about which treatment is better than letting surgeons or families choose.
- Evidence: Use the Clinic 1 versus Clinic 2 contrast and at least one feature of TOPS (randomization, , or intention-to-treat).
- Reasoning: Explain how random assignment makes the groups comparable, so the treatment becomes the believable cause of any difference.
How this is graded (rubric)
For: A colleague proposes: to find the better cleft palate surgery, let each family pick Surgery A or B, then compare the groups after five years. As PI, redesign this into a fair trial. (1) Replace the family-picks step with one sentence describing randomization. (2) Add one sentence describing who you would blind and why the surgeon cannot be blinded. (3) State the intention-to-treat rule for a child assigned A whose family later switched to B. (4) Name the one condition (equipoise) that must be true before it is even ethical to randomize.
| Criterion | Proficient | Developing | Beginning |
|---|---|---|---|
| Complete | Every required part of the artifact is present and filled in. | Most parts are present, but one is missing or left blank. | Several parts are missing. |
| Accurate | The science and data are correct and match the evidence. | Mostly correct, with a small factual slip. | Key science or data is wrong. |
| Scientific reasoning (CER) | States a claim, backs it with specific evidence, and explains the reasoning. | Has a claim and evidence, but the reasoning is thin or missing. | Gives an answer with no evidence or reasoning. |
| Professional communication | Clear, organized, and labeled the way a clinician or scientist would write it. | Readable but disorganized or missing labels. | Hard to follow. |
| Submitted | Turned in through the route named under Submit here and confirmed. | Turned in, but in the wrong place or unconfirmed. | Not turned in. |
How the model answer scores against this rubric
- CompleteProficient: Nothing is left blank: the model fills every part of "A colleague proposes: to find the better cleft palate surgery, let each family pick Surgery A or B, then compare the groups after five years. As PI, redesign this into a fair trial. (1) Replace the family-picks step with one sentence describing randomization. (2) Add one sentence describing who you would blind and why the surgeon cannot be blinded. (3) State the intention-to-treat rule for a child assigned A whose family later switched to B. (4) Name the one condition (equipoise) that must be true before it is even ethical to randomize.".
- AccurateProficient: Every number and claim matches the case evidence.
- Scientific reasoning (CER)Proficient: It names a claim, cites the specific evidence, and explains the reasoning, not just the answer.
- Professional communicationProficient: It is organized and labeled like a real chart note.
- SubmittedProficient: It would be attached to your class form or handed in, and confirmed.
What's next: We can design a fair trial on paper. But for Mateo's care, families face a real fight that lasted decades: at what age should a be repaired? Earlier might help speech, but might harm facial growth. How did scientists run a real trial to settle that exact question, and what did they decide? We chase that next time.