title: Three programs for computing Dunn-Sidák critical values.
abstract: The Dunn-Sidák multiple comparison procedure is used to test hypotheses and construct confidence intervals for two or more a priori nonorthogonal contrasts for population means. The procedure uses a levels that are not available in conventional t tables. In 1977 Games prepared a table of two tailed critical values that simplifies using the procedure. Researchers are accustomed to doubling alpha in a two-tailed t table to obtain the critical value in one tail. Unfortunately, doubling alpha in Games's table always gives one tailed critical values that are too small. Computational routines using the t inverse function in Microsoft Excel 98, SAS, and SPSS are presented for obtaining Dunn-Sidák one- and two-tailed critical values for ant familywise error rate, number of contrasts, and error degrees of freedom.
authors.affiliation: Department of Psychology and Neuroscience, Baylor University, Waco, TX 76798-7334, USA.
authors.forename: R E
authors.initials: RE
authors.lastname: Kirk
authors.forename: F
authors.initials: F
authors.lastname: Natanegara
mesh_terms: D016001:Confidence Intervals; D003627:Data Interpretation, Statistical; D006801:Humans; D015233:Models, Statistical