Analysis of Categorical Data
So far we have performed hypothesis tests on categorical variables with only two
categories (levels). How do we handle categorical variables with more than 2
Question of Interest
How well does the observed data fit with what we expect it to be like?
We conduct a Goodness of Fit Test
Before conducting a study, we must have an expected proportion for each category. We use
this proportion to find the expected number of observations in each category.
After conducting a study, each category will have an observed proportion and an observed
number of observations.
Based on the observed counts, can we conclude that our expected counts are correct, or is
there evidence to conclude that the expected counts are incorrect?
Hypotheses for k categories
We assume expec