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)

Two recent indices of fit, the Relative Noncentrality Index (RNI) (R. P. McDonald and H. W. Marsh, 1990) and the Comparative Fit Index (P. M. Bentler, 1990), are shown to be algebraically equivalent in most applications, although one condition in which the RNI may be advantageous for model comparison is identified. (SLD)

This National Council on Measurement in Education (NCME) instructional module compares classical test theory and item response theory and describes their applications in test development. Related concepts, models, and methods are explored; and advantages and disadvantages of each framework are reviewed. (SLD)

A class of models is presented for gamma distributed random variables. These additive, multiplicative, and combined additive-multiplicative models are more flexible than classical linear models with respect to the structure that can be imposed on expected values. As a special case, a class of psychometric models for reaction times is presented.…

Describes the outcomes of an intensive one-month mathematical modeling course and the use of posters in peer assessment of student work. (Author/ASK)

Comments that fuzzy-trace theory is broadly comprehensive and contains compelling experimental manipulations; debates assumptions of the theory. Describes aspects of the historical and theoretical context of the theory and its usefulness in organizing false memory phenomena. Suggests some limitations concerning the representation of child…

Describes the origins of fuzzy-trace theory, including Piagetian, interference, information-processing, and judgment and decision-making influences. Discusses similarities and differences between fuzzy-trace theory and other approaches to memory falsification. Considers the theory's predictions regarding age differences in memory falsification and…

Describes and evaluates a peer-tutoring scheme to support the learning of mathematical models and mathematical modeling that was developed at the University of Ulster. The benefits of group work, assessment of student assignments, and limitations of the study are discussed. (Author/LRW)