The procedures required to obtain the approximate posterior standard deviations of the parameters in the three commonly used item response models for dichotomous items are described and used to generate values for some common situations. The results were compared with those obtained from maximum likelihood estimation. It is shown that the use of…

Two software packages commonly used for multidimensional item response theory (IRT) models require the user to input values for the lower asymptotes of the item response functions. One way of selecting these values is to estimate lower asymptotes with a one-dimensional IRT model and use those estimates as fixed values in the multidimensional…

Type I error rates for PARSCALE's fit statistic were examined. Data were generated to fit the partial credit or graded response model, with test lengths of 10 or 20 items. The ability distribution was simulated to be either normal or uniform. Type I error rates were inflated for the shorter test length and, for the graded-response model, also for…

Almost all modern rotation of factor loadings is based on optimizing a criterion, for example, the quartimax criterion for quartimax rotation. Recent advancements in numerical methods have led to general orthogonal and oblique algorithms for optimizing essentially any rotation criterion. All that is required for a specific application is a…

Beginning with Version 11, SPSS implemented the MIXED procedure, which is capable of performing many common hierarchical linear model analyses. The purpose of this article was to provide a tutorial for performing cross-sectional and longitudinal analyses using this popular software platform. In doing so, the authors borrowed heavily from Singer's…

An Excel program developed to assist researchers in the determination and presentation of confidence intervals around commonly used score reliability coefficients is described. The software includes programs to determine confidence intervals for Cronbachs alpha, Pearson r-based coefficients such as those used in test-retest and alternate forms…

Uses a sample data set to describe in nonmathematical terms how to implement and interpret results from a best-subsets logistic regression using the Statistical Analysis System. (SLD)

Uses a few heuristic examples to show how bootstrap analysis can be accomplished using some commonly available software programs. Until bootstrap analysis becomes an automated program option in standard statistical software, quantitative researchers may have to make do with these. (SLD)

Studied the use of an automated grader to score essays holistically and by rating traits through two experiments that evaluated 807 Web-based essays and then compared 386 essays to evaluations by 6 human raters. Results show the essay grading software to be efficient and able to grade about six documents a second. (SLD)

The present study compares vertical scaling results for the Rasch model from BILOG-MG and WINSTEPS. The item and ability parameters for the real and simulated mathematics tests were scaled across five grades, second to sixth. The simulated data were based on real data for a series of mathematics tests for Grades 2 to 6. The results from WINSTEPS…

The article describes a Windows program to estimate the expected value and sampling distribution function of the adverse impact ratio for general multistage selections. The results of the program can also be used to predict the risk that a future selection decision will result in an outcome that reflects the presence of adverse impact. The method…