摘要: Abstract This article proposes two new stepwise multiple comparison significance tests which control the experimentwise type I error rate and compares these with some existing procedures. The (step-up) begin by examining gaps between adjacent ordered sample means, then three stretches, etc., until range is reached. reverses a procedure (step-down) proposed Ryan (1960). Tables for were constructed using improved Monte Carlo techniques. A simulation study showed that one of step-up modification provided significantly greater power than commonly used Tukey honestly significant difference test.