Each of the four classic multivariate analysis of variance (MANOVA) tests of statistical significance may lead a researcher to different decisions as to whether a null hypothesis should be rejected: (1) Wilks' lambda; (2) Lawley-Hotelling trace criterion; (3) Roy's greatest characteristic root criterion; and (4) Pillai's trace criterion. These four omnibus test statistics are discussed and their optimal uses illustrated using hypothetical data sets. Discriminant analysis as a post hoc method to MANOVA is illustrated in detail. Once a significant MANOVA has been found, the next step is to interpret the non-chance association between dependent and independent variables. (Author/GDC)