List all variables whose levels form distinct categories in the model in the Class Variables field. Indicator variables are created for each level of each variable. If you do not specify an effect, then the numerical values of the variables are used directly in the model as in linear regression .Note : The order in which you specify class variables determines how LSMeans and interaction effects are sorted.All of the variables from the specified experimental design data set are listed in the Available Variables field.

Highlight variable(s) from the Available Variables field.

Click to add the highlighted variable(s) to the Class Variables field.