A chi-square test of independence can be used to determine if there is a relationship between two categorical variables. It is a nonparametric hypothesis test for nominal and ordinal variables. Nominal variables are simply named or labeled without order, like eye color or gender. Ordinal variables have a specific order between their options, such as education level or customer satisfaction ratings. A chi-square test can test if two such variables, like education level and customer purchases, are independent of each other.

1. Chi-Square Test
for
Independence

2. What is a Chi-Square Test for Independence?
A chi-square (Χ2) test of independence is
a nonparametric hypothesis test. You can use it to test whether
two categorical variables are related to each other.

3. What is a nominal and ordinal variables?
Nominal scale is a naming scale, where variables are simply
“named” or labeled, with no specific order. Ordinal scale has
all its variables in a specific order, beyond just naming them.
Interval scale offers labels, order, as well as, a specific
interval between each of its variable options.
Nominal Data Ordinal Data
Examples: Eye color,
housing style, gender, hair
color, religion, marital
status, ethnicity, etc
Examples: Economic
status, customer
satisfaction, education
level, letter grades, etc