The chemical model for autocatalytic reactions is adapted to the process of adopting educational innovations and is then applied to six sets of historical data. (Author/IRT)

A test theory model based on the Thurstone judgmental model is described. By restricting various parameters of the model, 3 Rasch models, 2 pseudo-Rasch models, 3 two-parameter models, and a Weber's Law model are derived. (Author/CTM)

An analysis of the question of the optimal depth of indexing in order to design an effective document retrieval system is presented. It is shown that some more fundamental questions about indexing and retrieval rather than indexing depth are central to the issue. (Author/MBR)

J. W. Atkinson expectancy-value theory of motivation is discussed and embellished. Possible ways to enhance student motivation through instructional design are proposed for further study. (BD)

Three counterexamples demonstrate that the Dutch Identity conjecture of P. Holland about examinee ability (1990) does not hold in general. The counterexamples suggest that only under strong assumptions can it be true that the limits of log-manifest probabilities are quadratic. Three propositions giving such strong conditions are given. (Author/SLD)

This paper presents two probabilistic models based on the logistic and the normal distribution for the analysis of dependencies in individual paired comparison judgments such as might occur in educational research. Three applications illustrate the approach. (SLD)

It is shown that, for equivalent structural equation models that have been extended to multigroup models, imposing cross-group equality constraints on no parameters, all parameters, or any number of parameters for which the models are identical preserves the model equivalence property. Results are illustrated with two-group cognitive intervention…

The issue of indeterminacy in factor analysis and the debate between the proposed alternative solution and posterior moment position are explored in an article and 14 commentaries and rebuttals in two rounds. Implications for applied work involving factor analysis are discussed. (SLD)

Reviews the use of structural equation modeling for providing an overall assessment of mediation, the mechanism that accounts for the relation between the predictor and the criterion. A strategy for supplemental details is presented that measures the magnitude of mediational effects. (SLD)

Describes an information retrieval, visualization, and manipulation model which offers the user multiple ways to exploit the retrieval set, based on weighted query terms, via an interactive interface. Outlines the mathematical model and describes an information retrieval application built on the model to search structured and full-text files.…

Presents model for analyzing the distribution and interaction costs of asynchronous distance courses with traditional on-campus courses. (PKP)

Discusses students' exploration of a particular rational function in the context of people waiting in line for service. The concepts of domain, range, and asymptotes are also developed in that context as is the effect of changes in input variables on function outputs. (Author/NB)

Examines the impact of a school-based assessment system on the implementation of an applications/modeling-based curriculum at the senior secondary level. The persistence of high task scaffolding in assessment tasks throughout the course and the concerns of teachers about the reliability and ownership of assessment in unsupervised conditions…

Developed a multidimensional Rasch model that is a multidimensional extension of item component models and determined relations to existing multidimensional item response theory models. Applied the model to a questionnaire on students' interest in physics to demonstrate that model parameters can be estimated even when 17 latent dimensions are to…

Reviews methods for handling missing data in a research study. Model-based methods, such as maximum likelihood using the EM algorithm and multiple imputation, hold more promise than ad hoc methods. Although model-based methods require more specialized computer programs and assumptions about the nature of missing data, these methods are appropriate…