APPROXIMATE AND EXACT DISTRIBUTIONS OF RANK-TESTS FOR BALANCED INCOMPLETE BLOCK-DESIGNS

Judges rank Ic out of t objects according to m replications of a basic balanced incomplete block design with b blocks. In Alvo and Cabilio (1991), it is shown that the Durbin test, which is the usual test in this situation, can be written in terms of Spearman correlations between the blocks, and using a Kendall correlation, they generated a new statistic for this situation. This Kendall tau based statistic has a richer support than the Durbin statistic, and is at least as efficient. In the present paper, exact aad simulation based tables are generated for both statistics, and various approximations to these null distributions are considered and compared.