Confirmatory factor analysis was applied to test second- and higher-order factor models in the areas of structure of abilities, allometry, and the separation of specific and error variance estimates. The estimation of validity and reliability, second-order models within factor analysis models, and the concept of discriminability were also studied.…

A model was developed for estimating individuals' true changes on test scores using the additional information provided by an auxiliary variable correlated with a trait being measured. This provides an improved and more precise estimate when compared with simple difference scores. It involves the reliability of "X" scores only. (SLD)

An alternative definition has been developed of the delta scale of item difficulty used at Educational Testing Service. The traditional delta scale uses an inverse normal transformation based on normal ogive models developed years ago. However, no use is made of this fact in typical uses of item deltas. It is simply one way to make the probability…

Eight formula-based estimates of population squared cross-validity and nine estimates of factor scores were compared with estimates from the conventional cross-validation procedure. Burket's and Rozeboom's formula-based estimates of population squared cross-validity in combination with a factor score method offer the most for practitioners…

The impact of misspecification on the estimation, testing, and improvement of structural equation models was assessed via a population study in which a prototypical latent variable model was misspecified. Results provide insights into the maximum likelihood estimator versus a limited two-stage least squares estimator in LISREL. (TJH)

Single sample approximations are considered for the cross-validation coefficient in the analysis of covariance structures. Results of a random sampling experiment--using data from ability tests administered to high school students (sample sizes 100, 400, and 800)--illustrate the coefficient and adjustment for predictive validity. (SLD)

Methods for examining the viability of assumptions underlying generalized linear models are considered. By appealing to the likelihood, a natural generalization of the raw residual plot for normal theory models is derived and is applied to investigating potential misspecification of the linear predictor. A smooth version of the plot is also…

Results of empirical validation studies of six statistical models available for indirectly estimating the need for alcohol, drug abuse, and mental health services across a large geographic area are presented. Models were evaluated using Colorado Social Health Survey data for 4,745 adults from 48 subareas of Colorado. (SLD)

This study examined the accuracy of predictions of college grades in English, mathematics, social studies, and natural science courses, and the accuracy of predictions of overall freshman grade point average (GPA) based on American College Testing Program (ACT) assessment test scores and on high school course work and grade information from the…