1. Using statistical notation, state the null hypothesis tested by case-control studies. [1]
2. You are performing a test to compare an observed proportion to a hypothetical "null" (p0). Where might p0 come from? [2]
3. You are performing an ANOVA comparing three independent groups. Write the null and alternative hypotheses that are being tested. [2]
4. The Kruskal-Wallis is said to be more robust than ANOVA because it can be used under a greater number of conditions. Why is this so? [2]
5. When is Fisher's test used in place of a chi-squared test? [1]
6. What distinguishes experimental studies from observational studies. [1]
7. What distinguishes case-control studies from cohort studies? [1]
8. Define confounding. [2]
9. Define interaction. [2]
10. What are the necessary preconditions for confounding? [2]
11. We find significantly different odds ratios in different strata. What does this suggest? [1]
12. An adjusted (Mantel-Haenszel summary) relative risk leaves us with a distinctly different impression of risk compared to a crude relative risk. What does this suggest? [1]