Contingency table

Definition

A contingency table, also known as a cross-tabulation or crosstab, is a type of table in a matrix format that displays the frequency distribution of variables. It helps to analyze the relationship between two categorical variables.

5 Must Know Facts For Your Next Test

1. Contingency tables are used to summarize categorical data and show the frequency distribution across different categories.
2. The rows and columns of a contingency table represent different categories of the two variables being analyzed.
3. Chi-square tests of independence are commonly used with contingency tables to determine if there is a significant association between the variables.
4. Expected frequencies in each cell of the table can be calculated using the marginal totals and overall sample size.
5. Contingency tables can be of any size but are most commonly 2x2, which compares two binary variables.

Review Questions

• What purpose do contingency tables serve in analyzing data?
• How are expected frequencies calculated in a contingency table?
• What statistical test is commonly associated with contingency tables to determine independence?

Related terms

Chi-Square Test of Independence: A statistical test used to determine whether there is a significant association between two categorical variables in a contingency table.

Marginal Total: The sum of frequencies for each row or column in a contingency table, representing the total count for one variable.

Expected Frequency:

The theoretical frequency for each cell in a contingency table, calculated based on marginal totals and assuming no association between variables.