Some distribution-free rane-like statistics having the mann-whitney-wilcoxon null distribution

In this note we suggest a class of two-sample test statistics iich have, as their null distribution,the Mann-Whitney-Wilcoxon

ill distribution. An interesting property of these statistics is lat many are not rank statistics; that is, they cannot be coumplited from, the ranks of the original observations. However, they %e still distribution-free when the two populations are identi-il. This class contains the Mann-Whitney-Wilcoxon test for the niality of location parameters of two distributions and a two-aiaple test for equality of spreads of two distributions recently ivestigated by Fligner and Killeen (1976)