Whether the one- or two-factor Wechsler or weighted sum scores (WSS) structural models adequately fit the Wechsler Intelligence Scale for Children III (WISC-III) covariance matrices was studied with samples of 2200 and 1118 children from previous studies. Both the WSS and supplemented models provided better fit than Wechsler's model but still…

Multidimensional scaling (MDS) and exploratory and confirmatory factor analyses were compared in the assessment of the dimensionality of data sets, using sets generated to be one-dimensional or two-dimensional and differing in degree of interdimensional correlation and number of items defining a dimension. (SLD)

The representation of multivariate data by icons is discussed. The factorial sun is suggested as superior to the commonly used snowflake or sun icons and as better representing the values of the different variables and their correlational structure. Two experiments with 60 college students demonstrate the factorial sun's superiority. (SLD)

Structure of measures of speed was studied by conducting simultaneous confirmatory factor analysis for 1 sample of 149 elderly adults and a sample of 147 young adults using 16 measures of speed. Five first-order factors of speed were found, as hypothesized, and three second-order speed factors were necessary. (SLD)

Two issues in analysis of interactions in complex linear models are considered. One is the omnibus test for interaction, and the other concerns follow-up tests when the omnibus test is significant. Reconsidered omnibus and follow-up tests are illustrated on an educational data set analyzed using the Statistical Analysis System. (SLD)

The question of whether test factor structure is indicative of the test item hierarchy was examined. Data from 1,000 subjects on two sets of five bivalued Law School Admission Test items, which were analyzed with latent trait methods of Bock and Lieberman and of Christoffersson in Psychometrika, were analyzed with an ordering-theoretic method to…

The study of the same people at several occasions is known by various names: panel studies, multi-wave, multi-variable models, cohort analysis, and gain score analysis. The use of econometric concepts, path analysis, and structural equation analysis to study multi-wave, multi-variable models became widespread in methodological practice in the late…

A questionnaire measuring affective, conative, and cognitive responses to 3 aspects of Black advancement in the workplace was administered to 128 White English-speaking and 140 Afrikaans-speaking South Africans. Results of confirmatory, single-group, and multigroup analyses of the data indicate that the structures were very similar across the…

The cognitive structure of an algebra test was defined and validated using the linear test model (LLTM) and quadratic assignment (QA) techniques. The LLTM is an extension of the Rasch model with a linear constraint that describes item difficulty in terms of the cognitive operations required to solve the item. The model permits the specification of…