6 - Analyses for Non-continuous Data

Summary

A contingency table is a table that shows the distribution of one variable within categories of another, like gender vs. disease/no disease. These tables can be 2 × 2, 2 × 3, 2 × 4 (if you were to examine gender by race, for example), 2 × 6, etc. The second variable can have two values (such as yes or no) or three or more values like race (White, African American, Asian, etc.). When examining a 2 × 2 table like disease by gender, one would test for statistical significance using chi-square (χ) analysis. However, like ANOVA (Section 4.3.2), when including a variable that has more than two categories, like race, you can run the χ statistic but there are so many resulting cells, you won’t really know where the statistical differences lie since you are examining so many categories at once.