A computerized adaptive test (CAT) administration usually requires a large supply of items with accurately estimated psychometric properties, such as item response theory (IRT) parameter estimates, to ensure the precision of examinee ability estimation. However, an estimated IRT model of a given item in any given pool does not always correctly…

Concentrates on studies of growth, composition (industry and population), and spatial form of urban areas--models of growth and intraurban land use, and urban simulation and efforts to build large scale statistical models for analyzing the impact of government policies on patterns of urban development. (RJ)

Techniques for digitalizing analog signal data are presented and compared. The techniques presented are: boxcar averaging, ensemble averaging, unweighted digital filter, weighted digital filter, and analog filter. (BB)

Simulates effects on educational expenditures in the Boston metropolitan area of establishing a statewide tax on commercial and industrial property to finance state aid for education. Concludes that removing business property from the local tax base for education would adversely affect the pattern of educational expenditures in the Boston area.…

Focuses on Elman's (1990) statistical analyses of the hidden unit activation patterns in his simple recurrent network on sentence prediction, first to highlight the feasibility of such analyses and then to show how connectionist explanations contribute to the development of effective explanatory theories. Argues for the evolutionary nature of…

In applying I. I. Bejar's method for detecting the dimensionality of achievement tests, researchers should be cautious in interpreting the slope of the principal axis. Other information from the data is needed in conjunction with Bejar's method of addressing item dimensionality. (SLD)

This study examined the effectiveness and efficiency of a three-dimensional virtual-reality simulation model designed to train kindergarten teachers in the understanding of kindergarten children's needs and perceptions. Results of statistical analysis indicated that the virtual-reality simulation was more effective than a workshop method.…

The authors conducted a Monte Carlo simulation of 4 test statistics or comparing dependent correlations with no variables in common. Empirical Type 1 error rates and power estimates were determined for K. Pearson and L. N. G. Filon's (1898) z, O. J. Dunn and V. A. Clark's (1969) z, J. H. Steiger's (1980) original modification of Dunn and Clark's…

Describes and evaluates three computer-assisted simulations used with Statistical Package for the Social Sciences (SPSS) and Microsoft Excel. Designed the simulations to reinforce and enhance student understanding of sampling distributions, confidence intervals, and significance tests. Reports evaluations revealed improved student comprehension of…

Differential item functioning (DIF) continues to receive attention both in applied and methodological studies. Because DIF can be an indicator of irrelevant variance that can influence test scores, continuing to evaluate and improve the accuracy of detection methods is an essential step in gathering score validity evidence. Methods for detecting…

Purpose: The purpose of this study was to develop guidelines for the statistical analysis of percentage of syllables stuttered (%SS) data in stuttering research. Method; Data on %SS from various independent sources were used to develop a statistical model to describe this type of data. On the basis of this model, %SS data were simulated with…

The purpose of this research is to demonstrate that a systematic approach to the graphical analysis of Rasch model residuals can lead to an increased understanding of ordered response data, and that residual patterns do change in predictable ways, and that summary statistics need not be the only piece of evidence for assuring the fit between model…

This paper extends the theory of conditional covariances to polytomous items. It has been mathematically proven that under some mild conditions, commonly assumed in the analysis of response data, the conditional covariance of two items, dichotomously or polytomously scored, is positive if the two items are dimensionally homogeneous and negative…

Two iterative procedures for constructing Rasch scales are presented. A log-likelihood ratio test based on a quasi-loglinear formulation of the Rasch model is given by which one item at a time can be deleted from or added to an initial item set. In the so-called "top-down" algorithm, items are stepwise deleted from a relatively large…

These symposium papers discuss the instructional use of computers in psychology, with emphasis on computer-produced simulations. The first, by Rich Edwards, briefly outlines LABSIM, a general purpose system of FORTRAN programs which simulate data collection in more than a dozen experimental models in psychology and are designed to train students…