## Description

Contingency tables (sometimes called crosstabs) are used to summarize and analyze the joint distribution of two variables, possibly stratified by a third. A table of observation counts will be created for each combination of the variables in the row list and each variable in the column list. If a stratum variable is specified, separate tables are created for each level of the variable. Note that these are the sample values and are not adjusted for the RDS design.

## Dialog

To create a contingency table, choose **Contingency Tables** from the **Analysis** menu on the menu bar of the Console window. The following window will appear.

To create a contingency table to relate the answers to two different survey questions add the row variable and column variable to the appropriate spaces and click **Run**. The results will appear in the Console Window.

## Cells

In addition to observation counts, there are a number of additional cell values that can be displayed.

- Percentages
- Row - Percentage in cell out of observations within each row
- Column - Percentage in cell out of observations within each column
- Total - Percentage in cell

- Chi-squared
- Expected - The expected count of the cell if there were no relationship between the two variables
- Residuals - The observed count minus the expected count.
- Standardized residuals - The residuals standardized such that (if the two variables were independent) they have mean 0 and standard deviation 1. These residuals are useful in determining which cells of a contingency table contribute most to a significant chi-squared test.
- Adjusted residuals - These adjust the residuals by the row and column totals.