The details of EM algorithms for maximum likelihood factor analysis are presented for both the exploratory and confirmatory models. An example is presented to demonstrate potential problems in other approaches to maximum likelihood factor analysis. (Author/JKS)

A handout, developed for use with students at Arizona State University, describes Gaussian Elimination procedures to be used when working with matrices. (MK)

Investigates the relationship between curriculum choice and occupational choice. The lag between curriculum choice and degree attainment generally ensures a mismatch between new labor supply and employer requirements, even if students are quite responsive to labor market conditions. (Author/CT)

Demonstrates that the process of comparing each document in an automated system with all others during the classification procedure may be avoided by the use of an inverted file. (FM)

A computer program which creates and stores a cumulative item covariance matrix upon each administration of an instrument is described. Use of this program would facilitate keeping a constant log on reliability in situations in which the test is administered to different groups over a period of time. (Author/JKS)

A program is described utilizing a microcomputer and tape drive with any contingency or chi-square table from 2x2 to 8x8. It requires only the entering of the number of rows and number of columns, plus one-time entry of cell frequencies. (Author/JKS)

The effect of stratified sampling of items based on item difficulty and/or interitem correlations on the estimation of test score distribution parameters using multiple matrix sampling was studied. Results indicated that stratification did not consistently improve the stability of parameter estimation. (Author/JKS)

This paper presents the generalized symmetric means approach to the estimation of population covariances, complete with derivations and examples. Particular attention is paid to the problem of missing data, which is handled very naturally in the incidence sampling framework. (CTM)

Describes how elementary linear algebra can be taught successfully while introducing students to the concept and practice of mathematical proof. Suggests exploring the concept of solvability of linear systems first via the row echelon form (REF). (Author/KHR)

A Monte Carlo simulation evaluated conditions that contribute to excessively high coefficients of congruence when fitting one factor pattern matrix into the space of a targeted pattern. Results support the conclusion that orthogonal Procrustes methods of factor rotation do produce spurious coefficients between predictor and criterion factor…

Discussion of the use of computers in math instruction highlights two possibilities suggested in response to an earlier journal column: (1) a program written in BASIC for producing spirolaterals, and (2) the use of LOGO list processing to solve matrix problems for exploring geometric transformations. (LRW)

An algorithm, based on a solution for C. I. Mosier's oblique Procrustes rotation problem, is presented for the best least-squares fitting correlation matrix approximating a given missing value or improper correlation matrix. Results are of interest for missing value and tetrachoric correlation, indefinite matrix correlation, and constrained…

Presents and demonstrates three new concepts in innovation diffusion: the attribution matrix, the innovation profile, and the potential for adoption rating that determines which among similar innovations is most likely to be adopted. This predictive model represents a means of conducting formative evaluation research about the potential for…

The impact of general control processing and working memory capacity on a measure of abstract intelligence was examined with 577 military recruits. A new multicomponent latent trait model for covert response was applied to item response data for matrix problems. General control processing has a stronger impact. (SLD)

Structural models that yield circumplex inequality patterns are reviewed, focusing on a model developed by T. W. Anderson (1960). A modification is proposed to this model to allow for negative correlations. This model may be reparameterized as a factor analysis model with nonlinear constraints on the factor loadings. (SLD)