We propose a hierarchical Bayesian model for analyzing multi-site experimental fMRI studies. Our method takes the hierarchical structure of the data (subjects are nested within sites, and there are multiple observations per subject) into account and allows for modeling between-site variation. Using posterior predictive model checking and model…

Coefficient Kappa is generally defined in terms of procedures of computation rather than in terms of a population. Here a population definition is proposed. Factors influencing the magnitude of Kappa are identified. Strategies to improve reliability are proposed, including that of combining multiple unreliable diagnoses. (Author/CTM)

Three approaches to the analysis of main and interaction effect hypotheses in nonorthogonal designs were compared in a 2 x 2 design for data that was neither normal in form nor equal in variance. The Welch-James test with trimmed means and Winsorized variances provided excellent Type I error control. (SLD)

A test for multisample sphericity based on the efficient scores criterion is obtained as an alternative to the likelihood ratio test developed by Mendoza. (Author)

The validity conditions for univariate repeated measures designs are described. Attention is focused on the sphericity (equality of variance) requirement. It is recommended that separate rather than pooled error term procedures be routinely used to test a priori hypotheses. (Author/JKS)

Redundancy analysis is an attempt to provide nonsymmetric measures of the dependence of one set of variables on another set. This paper attempts to clarify the nature of redundancy analysis and its relationships to canonical correlation and multivariate multiple linear regression. (Author/JKS)

Several ways of using traditional analysis of variance to test the homogeneity of variance in factorial designs with equal or unequal cell sizes are compared using theoretical and Monte Carlo results. (Author/JKS)

A general statistical model for simultaneous analysis of data from several groups is described. The model is primarily designed to be used for the analysis of covariance. The model can handle any number of covariates and criterion variables, and any number of treatment groups. (Author/JKS)

The locally best invariant test statistic for testing sphericity of normal distributions is shown to be a simple function of the Box/Geisser - Greenhouse degrees of freedom correction factor in a repeated measures design. Tables of the critical values of the Box/Geiser - Greenhouse correction factor are given. (Author/BW)

The statistical power of nine k-sample tests against ordered location alternatives under completely randomized designs are investigated. The results are intended to aid researchers in selecting appropriate statistical procedures. (Author/JKS)

A nonparametric test of dispersion with paired replicates data is described which involves jackknifing logarithmic transformations of the ratio of variance estimates for the pre- and posttreatment populations. Results from a simulation show that the test performs well under the null hypothesis and has good power properties. (Author/JKS)

Three analyses of pretest and posttest data are considered: (1) posttest only designs; (2) two-way repeated measures of analysis of variance (ANOVA); and (3) one-way analysis of covariance (ANCOVA). Conditions that ensure legitimacy of inferences about the equality of treatment effects on the latent variable theta are discussed. (SLD)

In this paper, the efficiency of conditional maximum likelihood (CML) and marginal maximum likelihood (MML) estimation of the item parameters of the Rasch model in incomplete designs is investigated. The use of the concept of F-information (Eggen, 2000) is generalized to incomplete testing designs. The scaled determinant of the F-information…

Repeated measures designs have traditionally been analyzed by the univariate mixed model approach, in which the repeated measures effect is tested against an error term based on the subject by treatment interaction. This paper considers an extension of this analysis to designs in which the individual repeated measures are multivariate. (Author/JKS)

A model for describing dynamic processes is constructed by combining the Rasch model with the concept of structurally incomplete designs. This is accomplished by mapping each item on a collection of virtual items, one of which is assumed to be presented to the respondent depending on preceding responses or feedback. (SLD)