Several goodness of fit (GOF) criteria have been developed to assist the researcher in interpreting structural equation models. However, the determination of GOF for structural equation models is not as straightforward as that for other statistical approaches in multivariate procedures. The four GOF criteria used across the commonly used…

A technique to estimate variances of weighted estimates in program evaluation is discussed. BRR estimates of variance are constructed from orthogonally weighted subsamples and can provide better estimates from complex samples than can other methods. Use of BRR is illustrated in a government evaluation of a food service program. (SLD)

The source of an event-related brain potential (ERP) is estimated from multivariate measures of ERP on the head under several mathematical and physical constraints on the parameters of the source model. Statistical aspects of estimation are discussed, and new tests are proposed. (SLD)

Mislevy (1984, 1985) introduced an EM algorithm for estimating the parameters of a latent distribution model that is used extensively by the National Assessment of Educational Progress. Second order asymptotic corrections are derived and applied along with more common first order asymptotic corrections to approximate the expectations required by…

A new method for evaluating model fit that is easy to use and interpret is presented. The new method, which uses a binomial test of the number of hypotheses (paths) in a model that are supported by the data, has heuristic value when considering problems associated with other goodness-of-fit measures. An application of the binomial test as a…

Methods of probability modeling to analyze rater agreement are described, emphasizing their basic similarities and viewing them as variants of a common methodology. Statistical techniques for analyzing agreement data are described to address questions such as how many opinions are required to make a medical diagnosis with necessary accuracy. Kappa…

The following models which provide an estimate of the reliability of a rating scale are described: (1) disattenuation; (2) common factor; (3) external criterion; (4) treatment effects; and (5) regression. Such models are especially useful in selecting, evaluating, and training participants in clinical research. (SLD)

Statistical significance and "abnormality" have been used as criteria for the evaluation of intra-individual subtest score differences. Shortcomings of these criteria are identified, and improved estimates of the true score differences are suggested. The applicability of the abnormality criterion to these improved estimates is reviewed.…

A procedure for evaluating a variety of rater reliability models is presented. A multivariate linear model is used to describe and assess a set of ratings. Parameters are represented in terms of a factor analytic model, and maximum likelihood methods test the model parameters. Illustrative examples are presented. (SLD)

Studies of differential item functioning (DIF) under item response theory require that item parameter estimates be placed on the same metric before comparisons can be made. Evidence that methods for linking metrics may be influenced by the presence of differentially functioning items has been inconsistent. The effects of three methods for linking…

The effects of certain characteristics (e.g., sample design) of National Assessment of Educational Progress (NAEP) data on statistical analysis techniques are considered. Ignoring special features of NAEP data and proceeding with a standard analysis can produce inferences that underestimate the true variability and overestimate the true degrees of…

A model-based approach to rater reliability for essays read by multiple readers is presented. Variation of rater severity (between-rater variation) and rater inconsistency (within-rater variation) is considered in the presence of between-examinee variation. An additive variance component model is posited and the method of moments for its…

A general longitudinal model is presented for estimating school effects and their stability. The model, capable of separating true changes from sampling and measurement error, controls statistically for effects of factors exogenous to the school system. The model is illustrated with data from large cohorts of students in Scotland. (SLD)

Forty blind children and adolescents had to learn two unknown environments and then externalize the spatial representation via two methods--building a scale model and verbally estimating distances. High correlations were found between the two methods and between those methods and two systems of measuring mobility. (Author/JDD)

Research in structured equation modeling (SEM) suggests that nonnormal data will invalidate chi-square tests and produce erroneous standard errors. However, much remains unknown about the extent to which, and the conditions under which nonnormal data can affect SEM application, especially when excessive skewness and kurtosis are present in data.…