The most familiar models of item response theory are defined at the level of individual subjects. It is possible, however, to define such models for groups of subjects. This paper discusses group-level item response models, their uses, and their relationships to subject-level models. (Author/JKS)

This report describes new statistical procedures for item response analysis using estimation of item response curves used in mental testing with ability parameters treated as a random sample. Modern computer technology and the EM algorithm make this solution possible. The research focused on the theoretical formulation and solution of maximum…

A test theory using only ordinal assumptions is presented, based on the idea that the test items are a sample from a universe of items. The sum across items of the ordinal relations for a pair of persons on the universe items is analogous to a true score. (SLD)

To determine the accuracy of simulated data sets, an investigation was conducted of the effects of item sampling plans in the application of multiple matrix sampling using both simulated and empirical data sets. Although results were similar, empirical data results were more precise. (SLD)

In studies involving matrix sampling on items, it is often the case that there are too few responses per individual to use latent trait item response models. A model is formulated wherein individual level variability appears as independent error within the cells of a cross classification of demographic variables. (JKS)

This study tests several explanations for discrepant results in an earlier study (Cook et al., 1985) which presented a partial pre-calibration method for equating new editions of the Scholastic Aptitude Test (SAT) to the same scale as older editions. In contrast to full pre-calibration, which seeks to equate all items from two or more editions,…

The effectiveness of multiple matrix sampling was examined in a study of 495 students' attitudes toward a computer education program. A post hoc analysis of variance was used, with the class as the unit of analysis. The Computer Attitude Scale, a 30-item rating scale, was used to measure attitudes toward learning about and working with computers.…