A procedure for obtaining Rasch model estimates of item difficulty and of ability is detailed. The procedure approximates the optimal but difficult to obtain "unconditional" estimates. (JKS)

An artifact encountered in regression models of human judgment is explored. The direction and magnitude of the artifactual effect is shown to depend upon the nature of the experimental task and task conditions. Use of an alternative index is recommended. (Author/JKS)

A general coefficient for tests, delta, is derived from a decision theoretic point of view. The situations are considered in which a true score is estimated by a function of the observed score, observed scores are split into more than two categories, and observed scores are split into only two categories. (Author/CTM)

An alternative formulation for Guttman scaling is presented. The new formulation is described, and advantages over Guttman's formulation are detailed. The method is assumption-free and capable of multidimensional analysis. (Author/JKS)

The strategy for investigating convergent and discriminant test validity, known as the multitrait-multimethod matrix, is investigated. A nonparametric significance testing procedure is suggested and demonstrated. (JKS)

The "Traveling Salesman" and similar combinatorial programming tasks encountered in operations research are discussed as possible data analysis models in psychology, for example, in developmental scaling, Guttman scaling, profile smoothing, and data array clustering. A short overview of various computational approaches from this area of…

An application of Samejima's latent trait model for continuous responses was applied using the Impulsivity and Harmavoidance scales of Jackson's Personality Research Form; attention was given to the requirement that the model be invariant across populations and sex groups. Responses from males were found to fit the model better than those from…

Econometric techniques for estimating the parameters of individual and group multi-attribute utility models are discussed. These techniques permit measurement of intra-and inter-individual heterogeneity with regard to the importance ascribed to the model attributes. (Author/JKS)

A rederivation of Lord's formula for estimating variance in multiple matrix sampling is presented as well as the ways Cronbach's coefficient alpha and the Spearman-Brown prophecy formula are related in this context. (Author/JKS)

A model is presented which allows for the prediction of relationships among stimuli when stimulus responses are linearly related to squared distances between stimulus scale values and person scores along a latent continuum. Applications to developmental and attitudinal data are discussed. (Author/JKS)

A model for the setting of mastery cut scores is presented. The model, based on the beta-binomial test distribution, allows for hand calculation of cut scores. The model provides a simple way to explore the consequences of selecting a particular cut score. (Author/JKS)

The analytical procedure of path analysis is described in terms of its use in nonexperimental settings in the social sciences. The description assumes a moderate statistical background on the part of the reader. (JKS)

Discusses an introductory chemical engineering course in which mathematical models are used to analyze experimental data. Concepts illustrated include dimensional analysis, scaleup, heat transfer, and energy conservation. (MLH)

The relationship between mathematics and chemistry has been changing rapidly in recent years. Some chemistry teachers have experienced difficulties in their teaching with the introduction of modern mathematics in the schools. Some suggestions for reinforcing the concepts and language of modern mathematics are put forth. (Author/MA)

Elementary differential calculus is used to analyze and to discuss some complex economic situations. (JT)