Classification procedures are common and useful in behavioral, educational, social, and managerial research. Supervised classification techniques such as discriminant function analysis assume training data are perfectly classified when estimating parameters or classifying. In contrast, unsupervised classification techniques such as finite mixture…

The authors compare the operating characteristics of the bootstrap-F approach, a direct extension of the work of Berkovits, Hancock, and Nevitt, with Huynh's improved general approximation (IGA) and the Brown-Forsythe (BF) multivariate approach in a mixed repeated measures design when normality and multisample sphericity assumptions do not hold.…

This paper analyzes ways in which the methods used to measure psychological constructs contribute invalidity to measurements. The analysis distinguishes between inadequacies stemming from the behaviors selected for measurement and the harmful effects generated by the measurement operations themselves. (BS)

A confirmatory factor analysis of 61 published data sets from multitrait-multimethod studies provides estimates of the trait, method, and error variances of measures used in the social and behavioral sciences. Traits accounted for less than 50 percent of the variance among construct measures overall. Implications for testing are discussed. (SLD)