On the Measures of Dispersion for Qualitative Data

Abstract

The index of qualitative variation (IQV) is defined as a measure of dispersion for qualitative (non-numerical) data. There are many indices of qualitative variation, but they are rarely mentioned in introductory statistics textbooks. Wilcox (1967) presented seven indices that can be used to measure qualitative variation. The main purpose of this paper is to mention the concept of dispersion for a qualitative data, submit seven formulas for its measurement, which is appropriate for an elementary course in statistics, and make comparison between the seven indices of qualitative variation (IQV) that are presented by Wilcox (1967). A Matlab computer program has been written to calculate such indices.