Question

When would you use a chi-square test, what are its assumptions, and what does the textbook recommend for reporting its effect size?

Answer 1

The chi-square statistic is commonly used for testing relationships between categorical variables. There are two types of chi-square tests:

• A chi-square goodness of fit test determines if a sample data matches a population.
• A chi-square test for independence compares two categorical variables to see if they are related.

The chi-square statistic requires that the following assumptions are met:

• The variables should be measured at an ordinal or nominal level (i.e., categorical data).
• The variables should consist of two or more categorical, independent groups.

There are three different measures of effect size for chi-squared test, Phi (?), Cramer's V (V), and odds ratio (OR).