Tables of the Studentized Augmented Range and Applications to Problems of Multiple Comparison

Tables of the upper α-points q'α, k, v of the studentized augmented range distribution with k and v degrees of freedom are given for 2 ≤ k ≤ 8, 12 values of v, and α = .01, .05, .10, and .20. Tukey's well-known approximation of q'α,k,v by the corresponding upper α-point qα,k,v of the studentized range distribution for k ≥ 3 and α ≤ .05 is shown to be as good, if not better, for cases where k ≥ 4 and α ≤ .20. For k ≥ 9, the approximation appears to be accurate to three decimals, as long as α ≤ .20. The primary application is that the Spjøtvoll-Stoline (1973) T' method of multiple comparison is exact and applicable for cases where α ≤ .20 with the use of the studentized augmented range tables.