Addendum to: Heterogeneity Coefficients for Mahalanobis' D as a Multivariate Effect Size

In a previous paper (Del Giudice, 2017 [Heterogeneity coefficients for Mahalanobis' D as a multivariate effect size. Multivariate Behavioral Research, 52, 216-221]), I proposed two heterogeneity coefficients for Mahalanobis' D based on the Gini coefficient, labeled H and EPV. In this addendum I discuss the limitations of the original approach and note that the proposed indices may overestimate heterogeneity under certain conditions. I then describe two revised indices H₂ and EPV₂, and illustrate the difference between the original and revised indices with some real-world data sets.