DESIGNATING "GROUPING VARIABLES" Grouping variables are those which classify other variables into groups. Usually, a grouping variable is a column having integer values from 1 to 4 or perhaps 0 and 1. The numbers indicate what groups your dependent variables belong to. Often, the integers are a code standing for different experimental conditions. You may have several grouping variables to obtain multiple classi- fication. If your grouping variable has ten or fewer values, BMD regards those values as codes used to classify other variables. If your grouping variable has more than ten values, you must specify in a grouping statement (later in this program) what the codes are in your grouping variable.