The CLASS statement specifies variables in the input data set that serve as indicator, dummy, or classification variables in the MODEL statement. If a CLASS variable is specified as an independent variable in the MODEL statement, the RELIABILITY procedure automatically generates an indicator variable for each level of the CLASS variable. The indicator variables generated are used as independent variables in the regression model specified in the MODEL statement. An indicator variable for a level of a CLASS variable is a variable equal to 1 for those observations corresponding to the level and equal to 0 for all other observations.