A general computer program for estimating the unknown coefficients in a set of linear structural equations is described. In its most general form, the variables in the equation system may be unmeasured hypothetical constructs or latent variables, and there may be several measured variables or multiple indicators for each unmeasured variable. Also,…

The 50 papers on educational evaluation presented at the 1972 AERA Conference are reviewed. The papers were classified into four categories: Theory and Methodology, Empirical Models, Empirical Studies, and Nationwide Evaluation and State Assessment. A list of the papers reviewed, their authors, and, when applicable, the ED numbers concludes the…

The effects of dynamic quantum allocation and swap-time variability on central processing unit (CPU) behavior are investigated using a model that allows both quantum length and swap-time to be state-dependent random variables. Effective CPU utilization is defined to be the proportion of a CPU busy period that is devoted to program processing, i.e.…

Two specific approaches of how to evaluate an information retrieval system are explored. The first is a mathematical model for use in studying how to minimize operating costs. The model provides a method for comparative evaluation between systems. The cost model divides the costs of a retrieval system into two components: system costs and user…

Several different mathematical methods for optimization of instruction are presented and compared. A way in which one of these methods might be applied to the measurement and avoidance of inequality in educational opportunity and performance is presented. Finally, it is suggested that computer-assisted instruction might provide a particularly…

Designed for the student of urban simulation, this paper offers definitions of "models"--conceptual or mathematics formulations of concrete things or of abstract relations between them--and of "simulation"--an act or process, conducted either by persons or devices, by which a model or a hierarchy of models is made to imitate reality. Six basic…

The Automatic Interaction Detector (AID) is discussed as to its usefulness in multiple regression analysis. The algorithm of AID-4 is a reversal of the model building process; it starts with the ultimate restricted model, namely, the whole group as a unit. By a unique splitting process maximizing the between sum of squares for the categories of…

This research is a study of demands for books in library circulation systems. Demand data for random samples of books were collected and fitted to various standard distributions. The numbers of demands for collections of books are shown to be Negative Binomially distributed. As is shown, this implies that the numbers of demands for individual…

A class of tests for normality using the ratio of two estimates of the standard deviation is generalized to provide a class of tests for multivariate normality using a characterization of the multivariate normal. The posers of some of the tests are examined numerically and compared with the power of a recent similar test. (Author)

Games (1973) criticized the Marascuilo and Levin (1970) "nested" or simple effects design as a poor substitute for the usual logic of a factorial analysis of variance. Marascuilo and Levin's use of "nesting" is completely idiosyncratic and contrary to well-established usage, thus confusing the student. Proper usage is…

Although analysis of variance is the most popular statistical tool to researchers in the behavioral sciences, the casual user has recognized only recently that there is no single correct way to perform such an analysis. This paper is concerned with hypotheses tested in the two-way, fixed model under a variety of conditions: (1) with and without…

The approaches taken to psychological research are discussed. Studies are classified as axiomatic, classical, stochastic or statistical, or structural. The mathematical models used in each type of study are discussed. (SD)

When the logistic function is substituted for the normal, Thurstone's Case V specialization of the law of comparative judgment for paired comparison responses gives an identical equation for the estimation of item scale values, as does the Rasch formulation for direct responses. Comparisons are made. (Author/CTM)

A rigorous definition for a factor analysis model and a complete solution of the factor score indeterminacy problem are presented in this technical paper. The meaning and application of these results are discussed. (Author/JKS)

A special case of Bloxom's version of Tucker's three mode factor analysis model is developed statistically. A goodness of fit test and an empirical example are presented. (Author/JKS)