The Stability of Three Indices of Relative Variable Contribution in Discriminant Analysis

An empirical comparison is made of three proposed indices of relative predictor variable contribution: (1) the scaled weights of the first discriminant function; (2) the total group estimates of the correlations between each predictor variable and the first function; and (3) the within-groups estimates of the correlations between each predictor variable and the first function. It was found that given a single run of an experiment, none of the indices was sufficiently reliable in identifying the rank-order of the variables except possibly when the total sample size was very large.