Year 9 Science · Unit 1 · Lesson 18
Challenge Worksheet
Learning Goals
Design a mini-experiment
A researcher wants to test: "Does sleep duration affect academic performance in Year 10 students at an Australian high school?" Plan an ethical investigation below. Justify each choice.
| Recommended study design (RCT, cohort, or case-control) and justification | |
| Target population and sample size considerations | |
| Independent variable (what is deliberately changed) | |
| Dependent variable (what is measured or observed as a result) | |
| Three potential confounding variables and how you would control for them | |
| How data would be collected (be specific, what instrument, how often) | |
| Two specific ethical considerations and how you would address each | |
| One limitation of your study design that could not be eliminated |
Evaluate Imagine your study finds a strong correlation: students sleeping fewer than 7 hours per night score 15% lower on average. A journalist writes the headline: "Sleep deprivation causes exam failure in Year 10 students." Using what you know from this lesson about correlation, causation, and confounding variables, identify TWO reasons why this headline overclaims what your study shows. For each reason, explain what additional evidence would be needed before a causal claim could be made.
Extend The 1932 Tuskegee Syphilis Study withheld treatment from Black American men with syphilis, without their knowledge or consent, for 40 years. Using what you know about ethical principles in disease research from this lesson, identify ONE specific ethical principle this study violated and explain why that principle exists in modern research guidelines.
Wrap Up
In one sentence, what is the hardest part of designing an ethical study of a real-world health question?