F. Samejima's approximation for the bias function for the maximum likelihood estimate of the latent trait in the general case where item responses are discrete is explored. Observations are made about the behavior of this bias function for the dichotomous response level in general. Empirical examples are given. (SLD)

A probabilistic choice model, based on L. L. Thurstone's Law of Comparative Judgment Case V, is developed for paired comparisons data about psychological stimuli. The model assumes that each stimulus is measured on a small number of physical variables. An algorithm for estimating parameters is illustrated with real data. (SLD)

Scoring of response vectors to give maximum test-retest correlation is investigated. A general method is given for finding the best scores, deriving them for the normal factor model, and showing that for a standard model for binary response it is easy to approximate the best scores. (SLD)

Polynomial algorithms are presented that are used to solve selected problems in test theory, and computational results from sample problems with several hundred decision variables are provided that demonstrate the benefits of these algorithms. The algorithms are based on optimization theory in networks (graphs). (SLD)

A connectionist model of argument strength that applies to categorical arguments involving natural categories and predicates about which subjects have few prior beliefs is proposed. This feature-based model was tested in argument strength rating studies with 34 undergraduates, and its validity is discussed. (SLD)

Principal component, image component, three types of factor score estimates, and one scale score method were compared over different levels of variables, saturations, sample sizes, variable to component ratios, and pattern rotations. There were virtually no overall differences among methods, with the average correlation between matched scores…

The problem of measuring impacts of employment and training programs when workers not receiving services are affected by the program is explored, using a reemployment bonus program as an example. The conventional measures of bonus impacts may significantly overestimate the net impact of the bonus offer. (SLD)

After a brief review of the contributions of factor analysis and regional analysis to the elaboration of the structures of spatial abilities, a facet design and regional model for spatial abilities are presented. A cylindrical-wedge model is proposed to represent the correlational structure of spatial ability tests. (SLD)

Describes a theoretical model based on binary vectors that was developed to improve relevance in information retrieval systems. Earlier probabilistic models are examined, quadratic and linear discriminant functions are discussed, relationships between queries and documents are considered, and further research is suggested. (15 references) (LRW)

Asymptotic distributions of H. Brogden's and F. Lord's modified sample biserial correlation coefficients (SBCCs) are derived. Asymptotic variances of these estimators are evaluated for bivariate normal populations and compared to the maximum likelihood estimator's asymptotic variance. These estimators are less variable than ordinary SBCCs when the…

A growth curve approach to longitudinal profile analysis is presented by which univariate and multivariate descriptions of achievement and rate of growth are provided, and intraindividual strengths and weaknesses are computed for profiles of achievement and progress. Analyses are reported for simulated data conforming to a straight-line growth…

Discusses distributed information retrieval systems that take into account the weights of descriptors from thesauri. Topics addressed include a mathematical model for information retrieval subsystems; organization of inverted files; models for the distributed homogeneous information systems; a distributed information retrieval system based on…

Performance of the logistic regression (LR) procedure was compared to that of the Mantel Haenszel (MH) procedure in the detection of uniform and nonuniform differential item functioning on a simulation examining distributional properties of the LR and MH test statistics and the relative power of the two procedures. (SLD)

A model for solving very large item selection problems is presented. The model builds on binary programming applied to test construction. A heuristic for selecting items that satisfy the constraints in the model is also presented, and various problems are solved using the model and heuristic. (SLD)

An approach to empirical Bayes analysis of aggregated survival data from different groups of subjects is presented based on a contingency table representation of data using transformations to permit the use of normal priors. Analysis of families of survival curves leads to improvements over classical estimates. (SLD)