The structure of information matrices in latent-variable models is explicated, and the degree to which missing information can be recovered by exploring collateral variables for respondents is characterized. Results are illustrated in the context of item-response-theory models, and practical implications are discussed. (SLD)

Multiple imputations for latent variables are constructed so that analyses treating them as true variables have the correct expectations for population characteristics. Analyzing multiple imputations in accordance with their construction yields correct estimates of population characteristics, whereas analyzing them as multiple indicators generally…

A framework is described for exploiting auxiliary information about test items within item response theory models to enhance parameter estimates. The method also provides diagnostic information about items' operating characteristics. An empirical Bayesian estimation of Rasch item difficulty is used to illustrate the principles involved. (TJH)

Marginal maximum likelihood estimation equations are derived for the structural parameters of the Saltus model, and a computing approximation is suggested based on the EM algorithm. The solution is illustrated with simulated data and an example from the domain of mixed number subtraction. (SLD)

Standard procedures for estimating item parameters in item response theory ignore collateral information that may be available about examinees. Circumstances under which collateral information about examinees may be used to make inferences about item parameters more precise and circumstances under which collateral information must be used are…

Relationships between Bayesian ability estimates and the parameters of a normal population distribution are derived in the context of classical test theory. Formulas are presented for practical work with Bayesian ability estimates, and a numerical illustration is provided. (SLD)

The basic equations of item response theory provide a foundation for inferring examinees' abilities and items' operating characteristics from observed responses. In practice, though, examinees will usually not have provided a response to every available item--for reasons that may or may not have been intended by the test administrator, and that…

A closed form approximation is given for the variance of examinee proficiency estimates in the Rasch model for dichotomous items, under the condition that only estimates, rather than true values, of item difficulty parameters are available. The term that must be added to the usual response-sampling variance is inversely proportional to both the…

Scaling methodologies used in analysis of National Assessment of Educational Progress (NAEP) surveys since 1984 are reviewed. The plausible values methodology developed for NAEP scale-score analyses is described in the contexts of item response theory and average response method scaling. Current NAEP research in scaling is discussed. (SLD)

This paper illustrates how, in the item-response theory framework, collateral information about test items can augment or replace examinee responses when linking or equating new tests to established scales, using data from the Pre-Professional Skills Test for approximately 40,000 examinees. Collateral information can predict item operating…

Concepts behind plausible values in estimating population characteristics from sparse matrix samples of item responses are discussed. The use of marginal analyses is described in the context of the National Assessment of Educational Progress, and the approach is illustrated with Scholastic Aptitude Test data for 9,075 high school seniors. (SLD)