The criteria for assessing convergent and discriminant validity proposed by D. T. Campbell and D. W. Fiske (1959) are shown to be inadequate for either the additive or multiplicative structures of data in a multitrait-multimethod matrix. Model-specific criteria are more promising for assessing convergent and discriminant validity. (Author/SLD)

This article compares two methods for analyzing small sets of repeated measures data under normal and non-normal heteroscedastic conditions: a mixed model approach with the Kenward-Roger correction and a multivariate extension of the modified Brown-Forsythe (BF) test. These procedures differ in their assumptions about the covariance structure of…