Intersection tests for Union hypotheses (IU tests) have been proposed for use in some multiple comparisons problems, see for instance Berger (1982), Laska and Meisner (1988), and Berger and Hsu (1996). In this paper, sharper IU tests are given for some restrictive multiple comparison problems. The restriction assumed in all these problems is that the multiple effects under consideration are all of the same sign. One and two sided examples where such assumptions are meaningful are discussed. Critical values for implementing the sharper procedure are given for selected values of the underlying study parameters, in addition to a method of using SAS to give a very good approximation to the critical value for any desired case.

References:

1. Berger, R. L. (1982). Multiparameter Hypothesis Testing and Acceptance Sampling. Technometrics 24, 295-300.
2. Berger, R. L. and Hsu, J. C. (1996). Bioequivalence Trials, Intersection-Union Tests, and Equivalence Confidence Sets. Statistical Science, 11, 283-319.
3. Laska, E.M. and Meisner, M.J. (1989). Testing whether an identified treatment is best. Biometrics, 45, 1139-1151.