The assumptions of the Rasch model are discussed and the Rasch model is reformulated as a quasi-independence model. Using ordinary contingency table methods, the Rasch model can be tested generally or against less restrictive quasi-loglinear models to investigate specific violations of its assumptions. (Author/BW)

In this paper the parameter identifiability and estimation of a general dynamic structural model under indirect observation is considered from a system theoretic perspective. (Author/LMO)

Various indices for measuring agreement among several raters on the presence or absence of a trait can be interpreted as intraclass correlation coefficients. Such a reformulation clarifies the relationships among the measures, simplifies the computations involved, and permits simple significance tests to be carried out. An illustrative example is…

Four types of metric scales are distinguished: absolute, ratio, difference, and interval. A general coefficient of association for two variables of the same scale type is developed which reduces to specific coefficients of association for each scale type. (NSF)

An alternative is proposed to the usual Interaction and Nested Analysis of Variance (ANOVA) models by which a researcher will be able to investigate both interaction and nested questions in the same experiment without committing Type IV errors. (RC)

The Rasch measurement model improves on traditional test construction by creating tests in which the person's ability is independent of the sample of items used and the norm group used to calibrate the test. This paper reviews the Rasch model by describing properties of the item characteristic curve (ICC) and discussing the utility of having…

Purpose of this paper is to provide an alternative formulation which allows for the model parameters to be determined given the structural specification of zero mean error and independence among errors for different items and between errors and true scores. (Authors)

In this paper the amount of frustration in a section of books is derived from a model that includes the effects of variable book circulation and the nondeterministic nature of book use. (Author/DH)

Some reasons are offered for the differences between survey findings and econometric results. (Editor)

A review is given of doubly-chained trees for information retrieval. It is shown that the chaining steps may be of different cost depending upon whether the step is vertical or horizontal. The problem of constructing an optimal retrieval tree is formulated mathematically and a solution procedure given. (5 references) (Author/KE)

A Mathematical model for use in studying how to minimize the cost of operating a mechanized retrieval system is developed. Through the use of cost analysis, the model provides a method for comparative evaluation between information retrieval systems. (15 references) (Author/SJ)