A model is proposed for analyzing ability tests which utilizes a cognitive approach to understanding test items and latent trait analysis for quantifying subjects responses to test items. The model adopts a multicomponent perspective on the processes involved in answering test items. (JKS)

Limitations and extensions of Feldt's approach to testing the equality of Cronbach's alpha coefficients in independent and matched samples are discussed. In particular, this approach is used to test equality of intraclass correlation coefficients. (Author)

A chain of lower bound inequalities leading to the greatest lower bound to reliability is established for the internal consistency of a composite of unit-weighted scores (such as a test). Algorithms for obtaining various reliability coefficients are presented. (Author/JKS)

A simple approximation to the conditional distribution of goodness-of-fit statistics for the Rasch model is presented that is used when item difficulties are known. The approximation, which is easily programmed, gives relatively accurate assessments of conditional p-values for tests of 10 or more items. (Author/SLD)

Presents a latent variable representation for multiple-choice items and option characteristic curves, and proposes a criterion for distractors based on distractor selection ratios. Results allow for testing the criterion from observable data without specifying a parametric form for the characteristic curves. (Author/SLD)

Studied whether ordered latent class models can be used as nonparametric item response theory (NIRT) models to scale polytomous models. Simulation findings show that the Bayesian estimation method presented can handle the inequality restrictions on the parameters and the sparseness of the data quite well. (SLD)

L. A. Goodman's loglinear formulation for bi-way contingency tables is extended to tables with or without missing cells and is used for exploratory purposes. Three-way tables and generalizations of correspondence analysis are deduced, and a generalized version of Goodman's algorithm is used to estimate scores in all cases. (Author/TJH)

A new model, the acceleration model, is proposed in the framework of the heterogeneous case of the graded response model, based on processing functions defined for a finite or enumerable number of steps. The model is expected to be useful in cognitive assessment. (SLD)

An item-response model for binary response data exhibiting the bi-factor structure is derived, and a practical parameter estimation method is developed. The model, which provides an alternate to the traditional conditionally independent unidimensional item response theory model, is illustrated with an example from psychiatric research. (SLD)

The current state of multidimensional scaling using the city-block metric is reviewed, with attention to (1) substantive and theoretical issues; (2) recent algorithmic developments and their implications for analysis; (3) isometries with other metrics; (4) links to graph-theoretic models; and (5) prospects for future development. (SLD)

A multidimensional model is presented for measuring learning and change based on item response theory. The model specifies a Wiener simplex pattern for involvement of initial ability and one or more modifiabilities in response potential for successive measurement occasions. Properties of the model are explored for several classical issues. (SLD)

Introduces and discusses the rationale and procedures of two nonparametric approaches to estimating the operating characteristic of a discrete item response, or the conditional probability, given the latent trait, that the examinee's response be that specific response. (SLD)

Multidimensional unfolding methods suffer from the degeneracy problem in almost all circumstances. Most degeneracies are easily recognized: the solutions are perfect but trivial, characterized by approximately equal distances between points from different sets. A definition of an absolutely degenerate solution is proposed, which makes clear that…

Two examples of behavioral measurement are explored--utility theory and a global psychophysical theory of intensity--that closely parallel the foundations of classical physical measurement in several ways. First, the qualitative attribute in question can be manipulated in two independent ways. Second, each method of manipulation is axiomatized and…

Methods for estimating the mean and variance of latent ability parameters of a normally distributed population that has been tested with Rasch model-calibrated test items are discussed. Methods for checking the normality of the population are also included. (JKS)