Multivariate Analysis: Data Reduction and Treatment Evaluation

In a recent article, Everitt (1975) discussed several problems with multivariate techniques. However, two useful applications of multivariate techniques were not covered. The present paper describes the use of factor analysis to reduce a large array of outcome variables to a statistically manageable number, and multivariate analysis of variance to determine the relative effectiveness of several treatment regimes where a single outcome variable cannot be specified. It is concluded that the advantages of a multivariate approach out-weigh the disadvantages, provided the researcher is careful in interpreting and reporting his results.