Discusses the hierarchical rater model (HRM) of R. Patz (1996) and shows how it can be used to scale examinees and items, model aspects of consensus among raters, and model individual rater severity and consistency effects. Also shows how the HRM fits into the generalizability theory framework. Compares the HRM to the conventional item response…

Proposed some modified asymptotic distribution free (ADF) test statistics with distributions that are approximated by F distributions. Empirical studies show that the distributions of the new statistics are more closely approximated by F distributions than are the original ADF statistics when referred to chi-square distributions. (SLD)

Presents a latent Markov model in which the latent states are regressed on time-constant and time-varying covariates by means of a system-logit model. In an illustration, 541 secondary-school students' interest in physics at different times is explained by the time-constant covariate sex and the time-varying covariate physics grade. (SLD)

Describes the maximum likelihood (ML) estimation of mean and covariance structure models when data are missing. Describes expectation maximization (EM), generalized expectation maximization, Fletcher-Powell, and Fisher-scoring algorithms for parameter estimation and shows how software can be used to implement each algorithm. (Author/SLD)

Presents a review of fundamental concepts and applications used to address the Behrens-Fisher problem (W. Behrens, 1929 and R. Fisher, 1935), a problem in testing the difference between two population means, through fiducial, Bayesian, and frequentist approaches. (Contains 86 references.) (SLD)

Two possible standard error formulas for the polytomous differential item functioning index proposed by N. J. Dorans and A. P. Schmitt (1991) were derived. These standard errors, and associated hypothesis-testing procedures, were evaluated through simulated data. The standard error that performed better is based on N. Mantel's (1963)…

This article considers the impact of missing data arising from balanced incomplete block (BIB) spiraled designs on the chi-square goodness-of-fit test in factor analysis. The new approach is shown to outperform the pairwise available case method for continuous variables and to be comparatively better for dichotomous variables. (SLD)