The Chi-square test of independence is a statistical method used to determine if there is a significant association between two categorical variables. It compares the observed frequencies in each category to the frequencies expected if the variables were independent. A high Chi-square value indicates a strong association, while a low value suggests independence. To perform the test, researchers create a contingency table that displays the frequency counts for each combination of the variables. The Chi-square statistic is then calculated, and the result is compared to a critical value from the Chi-square distribution to assess significance, typically using a significance level of 0.05.