THE EQUIVALENCE OF KAPPA AND DEL

The purpose of this paper is to demonstrate the formal equivalence of Cohen's weighted kappa (1960, 1968) and the del measure of prediction analysis techniques developed by Hildebrand, Laing, and Rosenthal in 1977 and of their sampling variances. This equivalence leads to interesting extensions of each statistic. In particular, two extensions are presented here: a measure of the maximum value of del is introduced, and a measure of precision for kappa is presented. Other possibilities are suggested for future research.