A Population Subgroup Multiple Comparison Computer Program Based Upon Categorical Data

Abstract

Much of the information obtained on a particular population within psychological and educational research involves categorical data, usually in the form of nominal responses to items on a questionnaire. It is often of interest to compare various sets of subgroups of the population with respect to their response distributions to the items on the questionnaire. Procedures for performing multiple subgroup comparisons have been presented by Snee (1974) and Gabriel (1966). The question considered is whether or not a set of subgroups is homogeneous over the item response categories. Furthermore, if a set of subgroups is declared heterogeneous for an item, which subsets of that set may also be declared heterogeneous? It could be necessary to perform subgroup comparisons based upon a combination of some categories of the item. The computer program presented in this paper allows a researcher to determine which subgroups of the population are heterogeneous for some combination of categories of a questionnaire item.