Chi-squared test

Steve Simon


This page is currently being updated from the earlier version of my website. Sorry that it is not yet fully available.

Dear Professor Mean, Can the Chi-square test be used for anything besides categorical data?

The Chi-square test exists in many different forms. It is useful for testing whether a categorical variable conforms to a set of hypothesized probabilities. It can also test whether two categorical variables are independent. Both of these tests involve comparing expected counts to observed counts.

There is also a Chi-square test for examining whether a sample variance is equal to a hypothesized value. For this test, you look at the ratio of the sample variance to the hypothesized variance.

Finally many nonparametric tests rely on the Chi-square distribution as an approximation when you don’t have exact tables available.

You can find an earlier version of this page on my original website.