An empirical comparison of three proposed indices of predictor variable potency is presented. These indices are: (1) the scaled weights of the first Fisher-type discriminant function, (2) the total group estimates of the correlations between each predictor variable and the first Fisher-type function, and (3) the within-groups estimates of the correlations between each predictor variable and the first Fisher-type function. It was found that given a single run of an experiment none of the indices were sufficiently reliable to be of great practical value in identifying potent variables except when the total sample size was very large. (Author)