1. Relations in Categorical Data

2. Contingency Tables (Two-way)
Ticket class and survival statistics from the Titanic

3. Two-way Table
This allows us to look at two categorical variables together
Each cell of the table gives us counts for the combination of the two given variables.

4. Variables
Row variable – the variable distributed in the rows of the two-way table. In this example: Survival
Column variable - the variable distributed in the columns of a two-way table. In this example: Class

5. Marginal Distribution
The margins, both on the right and on the bottom, give totals for each variable.
This is the marginal distribution for Class

6. Conditional Distributions
A conditional distribution shows the distribution of one variable for just the individuals who satisfy some condition on another variable.
The following is the conditional distribution of ticket Class, conditional on having survived:

7. Conditional Distributions (cont.)
The following is the conditional distribution of ticket Class, conditional on having perished: