QUICK TEST FOR COMPARING 2 POPULATIONS WITH BIVARIATE DATA

A simple nonparametric test is given for testing the equality of 2 populations when the observations (X, Y) are bivariate and the alternative of interest is that the conditional c.d.f. of Y given X for 1 population dominates that for the other for every value of X. A curve is fit through the combined set of data points and the conditional distribution of the number of points above the curve from 1 population is considered, given certain information (depending on the design of the experiment) on the combined set of data. When used to compare 2 bivariate distributions, the test reduces to Fisher''s exact test for 2 .times. 2 tables.