Contingency tables

Contingency analysis describes and visualizes the distribution of categorical variables, and makes inferences about the equality of proportions, independence of the variables, or agreement between variables.

• Contingency table
  A contingency table, also known as a cross-classification table, describes the relationships between two or more categorical variables.
• Grouped frequency plot
  A grouped or stacked frequency plot shows the joint or conditional distributions.
• Effect size
  An effect size estimates the magnitude of the difference of proportions or the association between two categorical variables.
• Relative risk
  Relative risk is the ratio of the probability of the event occurring in one group versus another group.
• Inferences about equality of proportions
  Inferences about the proportions in populations are made using random samples of data drawn from each population of interest.
• Inferences about independence
  Inferences about the independence between categorical variables are made using a random bivariate sample of data drawn from the population of interest.
• Mosaic plot
  A mosaic plot is a visual representation of the association between two variables.