Year 9 Science • AC9S9I06 • Authored homework
Validity, Reproducibility and Scientific Claims
Assess validity and reproducibility of methods and evaluate whether scientific claims are supported by enough relevant evidence. Use precise science language and support longer responses with clear reasoning.
Part A
Short-answer questions
What does validity mean for an investigation method?
What does reproducibility mean for a scientific method?
Why can a small sample weaken a claim?
What is an uncontrolled variable?
Why should a claim match the evidence collected?
What is one sign that a science claim may be exaggerated?
Why does peer review help evaluate claims?
How can bias affect data collection?
What question should you ask before trusting a product claim?
Correct this misconception: “If data supports my claim once, the claim is proven.”
Part B
Long-answer questions
Evaluate a claim that a drink improves concentration because five students felt more alert after drinking it.
A method has no control group, shuffled attempts and vague measurements. Explain how each weakness affects the claim.
Compare a strong evidence-based claim with a weak claim based mostly on opinion or advertising.
Analyse a health, cleaning, energy or fitness product claim. What evidence would be needed to test it fairly?
Explain how confirmation bias could affect how a student records observations.
Rewrite an overconfident conclusion so it accurately reflects limited evidence.
Describe how to improve a weak method so its results are more valid and reproducible.
Evaluate whether one surprising result should lead to a strong claim or further testing.
Create a checklist for judging whether a scientific claim is trustworthy.
Write a full evaluation of one claim, including method quality, evidence strength, limitations and final judgement.
Part C
Research and understanding task
Choose one science-related claim from an advertisement, article or social media post. Identify the claim, evidence provided, missing evidence, possible bias and your judgement.