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Contingency Table (Two-Way Table)

Definition

A contingency table, also known as a two-way table, is a tabular representation of categorical data that shows how two variables are related. It displays frequencies or counts for different combinations of categories from both variables.

Analogy

Think of a contingency table as a seating arrangement at an event where guests can choose between two options for food (e.g., chicken or vegetarian). The table shows how many guests chose each option based on their preferences.

Related terms

Marginal Distributions: Marginal distributions in a contingency table show the frequencies or proportions for individual variables separately without considering their relationship.

Conditional Probability: Conditional probability measures the likelihood of an event occurring given that another event has already occurred. In a contingency table, conditional probabilities can be calculated by dividing cell frequencies by row totals.

Chi-Square Test: A chi-square test is used to determine if there is an association between two categorical variables in a contingency table. It compares the observed frequencies to the expected frequencies under the assumption of independence.