𝜒2 Homogeneity/Independence Test

Common Hypotheses

• H0 :   there is no difference in the distribution of a variable across populations or treatments

• Ha :   there is a difference in the distribution of a variable across populations or treatments

Assumptions

• to test for independence: Samples are randomly selected using a simple random sample

• to test for homogeneity: Samples are randomly selected using a stratified random sample or randomized experiment.

• Sampling with replacement (or sample size < 10% N)

• All expected counts should be greater than 5

Sampling Distribution

𝜒2

TI Calculator:  Stat -> Tests ->  𝜒2-Test...

SPSS: Analyze -> Descriptive Statistics -> Crosstabs

Enter Rowds and Colummn

Choose Statistics...   Check Chi-Square

Choose Cells... Check Expected

For Frequency Table

Do the following steps first

Data -> Weight Cases...