From a Question to a Testable Hypothesis
Experimental Design domain · Lesson 2 of 20 · Biomedical Innovations (BI)
Today's goal: Students will write a testable hypothesis and its null hypothesis, and identify the independent variable, dependent variable, controlled variables, and control group for a study of Mateo's question.
This is a model of the work you should turn in. Use it to check your own: match the structure and the level of detail, do not copy it. Your wording should be your own.
Study-design card (surgery-timing question):
- Hypothesis: Repairing the palate at 6 months rather than 12 months reduces velopharyngeal insufficiency at age 5.
- Null hypothesis (H-zero): The 6-month and 12-month groups have the same rate of velopharyngeal insufficiency at age 5.
- Independent variable: timing of surgery (6 vs 12 months).
- Dependent variable: rate of velopharyngeal insufficiency at age 5.
- Two controlled variables: same standardized surgical technique for every child; same blinded speech-assessment method.
- Control group: the 12-month (standard-timing) group.
Result that would force rejection of the hypothesis: an equal or higher speech-problem rate in the 6-month group (for example 15.0% vs 15.0%) would fail to reject the null and count against the prediction.
This model shows the level of evidence and organization needed to complete: A completed variable card for a falsifiable cleft-surgery hypothesis.
- Identify the purpose, hazards, and required controls.
- Write the procedure in a usable order.
- Confirm materials, measurements, and waste handling before starting.
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: Underline which slot is the independent variable so a partner can check it is what you change, not what you measure.
The finished product above did not appear all at once. Here is the path from the question to the turned-in work, so you can follow the same steps.
- 1Start from today's question: What is deliberately changed?
- 2Work the Model and the Explore questions to reason it out before writing anything.
- 3Pull the specific evidence the product needs from the reading and any database you used.
- 4Write it up in the required format: Fill in a study-design card for Mateo's surgical-timing question: hypothesis, , , , two controlled variables, and ; then write one sentence naming the result that would force you to reject your hypothesis.
- 5Check it against the rubric, then submit.
| 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. |
- CompleteProficient: Nothing is left blank: the model fills every part of "Fill in a study-design card for Mateo's surgical-timing question: hypothesis, null hypothesis, independent variable, dependent variable, two controlled variables, and control group; then write one sentence naming the result that would force you to reject your hypothesis.".
- 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.
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: Identifying the independent variable, dependent variable, and control group.
- 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.