MISUSE OF MULTIVARIATE ANALYSIS OF VARIANCE IN BEHAVIORAL RESEARCH: THE FALLACY OF THE 'PROTECTED' F TEST

Researchers who examine multiple outcome variables sometimes invoke a multivariate analysis of variance approach known as the 'protected F test' to control for experimentwise Type I error rate. Unfortunately, this procedure affords protection against experimentwise Type I error only in rare instances. The purpose of the present paper is to present the case against the protected F test and to discuss alternative methods of controlling for Type I error, including the Bonferroni adjustment and descriptive discriminant analysis. The latter approach is briefly elaborated as a truly multivariate solution for multivariate phenomena. The author cites multiple examples of proper and improper use of multivariate analysis of variance in research on child development.