Inference for Categorical Variables
effect modification vs confounding
if we don't take effect modification into account, we get an over-generalized estimate of teh realtionship between the outcome and the exposure for the entire co-hort
looks at two binary categorical variables while adjusting for the value of a third categorical variable
NOTE: one-sample single proportion test gives a 95% CI – $\Chi^2$ does not!
Joint, Marginal and Conditional Probabilities
to assess a paired difference