§-Quick questions
NSWInvestigating ScienceModule 7: Fact or Fallacy?
Quick questions on Correlation versus causation: HSC Investigating Science Module 7
8short Q&A pairs drawn directly from our worked dot-point answer. For full context and worked exam questions, read the parent dot-point page.
What is the Bradford Hill criteria?Show answer
In 1965 the epidemiologist Sir Austin Bradford Hill proposed nine criteria for establishing causation from observational evidence. The criteria are not a checklist but a set of considerations to weigh.
What are spurious correlations?Show answer
The website _Spurious Correlations_ lists hundreds of statistically significant but absurd correlations:
What is 1. Confounding?Show answer
A third variable causes both. Ice cream sales and drowning deaths are correlated because both are caused by hot weather. Eating ice cream does not cause drowning.
What is 2. Reverse causation?Show answer
Y causes X, not X causes Y. People with depression sometimes use cannabis to self-medicate. A correlation between cannabis use and depression might reflect depression leading to cannabis use, rather than cannabis causing depression.
What is 3. Chance?Show answer
Random fluctuations produce statistical associations in large datasets. With 100 random tests, on average 5 will appear "significant" at p < 0.05 by chance alone.
What is q1?Show answer
Distinguish correlation from causation with one example of a correlation that is not causal. [3 marks]
What is q2?Show answer
A study reports that NSW students who eat breakfast have higher HSC marks. Outline two confounders and one method to control for them. [3 marks]
What is q3?Show answer
A vaccine-injury claim notes that some children develop autism diagnoses within months of MMR vaccination. (a) Identify the logical fallacy. (b) Explain the correct interpretation given that autism is usually diagnosed at the same age as MMR is given.