The presence of clustered data is common in the sociobehavioral sciences. One approach that specifically deals with clustered data but has seen little use in education is the generalized estimating equations (GEEs) approach. We provide a background on GEEs, discuss why it is appropriate for the analysis of clustered data, and provide worked…

Although many textbooks on multivariate statistics discuss the common factor analysis model, few of these books mention the problem of factor score indeterminacy (FSI). Thus, many students and contemporary researchers are unaware of an important fact. Namely, for any common factor model with known (or estimated) model parameters, infinite sets of…

Heterogeneity in response styles can affect the conclusions drawn from rating scale data. In particular, biased estimates can be expected if one ignores a tendency to middle categories or to extreme categories. An adjacent categories model is proposed that simultaneously models the content-related effects and the heterogeneity in response styles.…

In the case of trials with nested data, the optimal allocation of units depends on the budget, the costs, and the intracluster correlation coefficient. In general, the intracluster correlation coefficient is unknown in advance and an initial guess has to be made based on published values or subject matter knowledge. This initial estimate is likely…

A latent variable modeling method is outlined for constructing a confidence interval (CI) of a popular multivariate effect size measure. The procedure uses the conventional multivariate analysis of variance (MANOVA) setup and is applicable with large samples. The approach provides a population range of plausible values for the proportion of…

In this article, we discuss the effect of removing the independence assumptions between the residuals in two-level random effect models. We first consider removing the independence between the Level 2 residuals and instead assume that the vector of all residuals at the cluster level follows a general multivariate normal distribution. We…

Presents permutation procedures that jointly test for differences in location and scale among treatments in a completely randomized experimental design. Also considers extensions to multivariate data and provides efficient alternative permutation tests. (SLD)

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)

Outlines the multivariate latent distribution specification and the corresponding interpretation issues. Also shows the univariate formulation and some alternative parameterizations that are useful in the estimation phase. Illustrates the procedures through an application to student ratings data. (SLD)

Provides an overall test statistic to evaluate significance that yields 100% (1-alpha) confidence intervals for all linear combinations of effect sizes, shows how the stepdown Finite Intersection Test (N. Timm, 1995) may be used to test whether effect sizes are simultaneously different from zero, and illustrates the procedure. (SLD)

Presents an application of the EM-algorithm to two problems of estimation and testing in a multivariate normal distribution with missing data. The two models are tested applying the log-likelihood ratio test. Solves the problem of different and nonmonotone patterns of missing data by introducing suitable transformations and partitions of the data…

Provides power comparisons for three permutation tests and the Bartlett-Nanda-Pillai trace test (BNP) (M. Bartlett, 1939; D. Nanda, 1950; K. Pillai, 1955) in completely randomized experimental designs with correlated multivariate-dependent variables. The power of the BNP was generally found to be less than that of at least one of the permutation…

Shows how to test the hypothesis that a nonnested model fits a set of predictors when modeling multiple effect sizes in meta-analysis. Illustrates the procedure using data from previous studies of the effectiveness of coaching on performance on the Scholastic Aptitude Test. (SLD)

This article presents an interview with R. Darrell Bock. He served as president of the Psychometric Society from 1972-1973. He has received the National Council on Measurement in Education award for "Contributions to the Design and Analysis of Educational Assessment" in 1990, the Educational Testing Service award for "Distinguished Contributions…