7 - Multivariate Analysis of Variance and Covariance

Abstract

This chapter provides an overview of some of the conceptual details related to multivariate analysis of variance (MANOVA) and multivariate analysis of covariance (MANCOVA) using a design involving one or two grouping variables and a collection of response variables that may include some concomitant variables. The chapter begins with a discussion of the purposes of multivariate analyses and describe research situations found in the behavioral science literature that call for the use of a MANOVA or a MANCOVA. However, MANCOVA is more involved than MANOVA from three standpoints: substantive theory, study design, and data analysis. Next, the chapter describes some MANOVA design aspects with a focus on the initial choice of a response variable system and on sampling. It also discusses at length a number of suggested guidelines for data analysis strategies and for reporting and interpreting MANOVA results, and illustrates these guidelines using a research example. The chapter concludes with some recommended practices regarding the typical use of MANOVA and MANCOVA by applied researchers.