Latent trait test models for responses to dichotomously scored items are considered from the point of view of parameter estimation using a Bayesian statistical approach and the EM estimation algorithm. An example using the Rasch model is presented. (Author/JKS)

Using LISREL, the only types of constraints allowed are fixing parameters at a constant value and constraining parameters to be equal. In this paper, two new concepts ("phantom" and "imaginary" latent variables) are introduced which allow fairly general equality and inequality constraints on factor loadings and structural model…

Explains overeducation as an economic phenomenon using several labor-market models. Establishes theoretically the effect of overeducation on production, using a production function model that characterizes production as a two-phase process. (PGD)

It is shown that Trueswell's empirical 80/20 rule arises from type of stochastic model for library loans presented by Burrell and Cane. Particular attention is paid to previously suggested uses of rule in identifying "core collection" for library noting that length of time period is of crucial importance. (20 references) (EJS)

When the experimental units are measured twice, and the response variable is dichotomous, the equality of the two proportions is usally assessed by Mc Nemar's (1947) test. In this paper, Bayesian methods are presented for testing hypotheses regarding the two success probabilities in light of complete and incomplete data. (Author/BW)

Sixteen measures of reliability for two-category nominal scales are compared. Upon correcting for chance agreement, there are only five distinct indices: Fleiss's modification of A-sub-1, the phi coefficient, Cohen's kappa, and two intraclass coefficients. Recommendations for choosing an agreement index are made based on definitions, magnitude,…

This study, which measures the growth rates of the 25 largest ARL libraries from 1962-63 through 1973-74, tentatively identifies the collection size level past which growth-rate deceleration begins. (Author)

The article focuses on a specific method of constructing the concept of function. The core of this method is a didactic model that plays two roles together--on the one hand a role of a model of the concept of function and on the other hand a role of a model of physical phenomena that functions can represent. This synergy of modeling situations and…

In this workshop, we will continue to reflect on a models and modeling perspective to understand how students and teachers learn and reason about real life situations encountered in a mathematics and science classroom. We will discuss the idea of a model as a conceptual system that is expressed by using external representational media, and that is…

This book is combined with a Web site to allow the reader to acquire the basic concepts of item response theory without becoming enmeshed in the underlying mathematical and computational complexities. The first edition, with its accompanying software, was designed to give the reader access to the basic concepts of item response theory without…

Computer Algebra Systems (CAS) can be used to help understand the behavior of cubics and other families of curves. The analysis of the parameters associated with a family of curves can give insight into the behavior of the family and can be used within the context of a mathematical model to determine a policy for the implementation of the model in…

The concepts of quantitative and structural change are considered from a multivariate perspective. A hybrid of these two types of change, quantistructural change, is described. (CS)

Though unshelved books are a problem in every library, little systematic effort has been made to design an optimal solution. Presented here is a mathematical model that attempts to approach such a solution. (2 references) (Author/DH)

How far does the back end of a bus swing out as the driver makes a turn at an intersection?'' is the problem discussed. (MM)