A desirable property of the equamax criterion for analytic rotation in factor analysis is presented. (Author)

Bounds are obtained for a coefficient proposed by Kaiser as a measure of average correlation and the coefficient is given an interpretation in the context of reliability theory. It is suggested that the root-mean-square intercorrelation may be a more appropriate measure of degree of relationships among a group of variables. (Author)

Following the work of Tucker, Cooper, and Meredith, image and anti-image covariance matrices from a correlation matrix that may be singular are derived. The algebra of image and anti-image covariance matrices and the work of Tucker, Cooper, and Meredith are reviewed. (Author/JKS)

A direct proof of Tucker, Cooper, and Meredith's procedure for obtaining the squared multiple correlations from a singular correlation matrix is given. (Author)

A revised theorem is presented concerning uniqueness of minimum rank solutions in common factor analysis. (Author)

Whether to factor the image correlation matrix or to use a new model with an alpha factor analysis of it is mentioned, with particular reference to the determinacy problem. It is pointed out that the distribution of the images is sensibly multivariate normal, making for "better" factor analyses. (Author/CTM)

To assess association between rows of proximity matrices, H. de Vries (1993) introduces weighted average and row-wise average variants for Pearson's product-moment correlation, Spearman's rank correlation, and Kendall's rank correlation. For all three, the absolute value of the first variant is greater than or equal to the second. (SLD)

Demonstrates that traditional exploratory factor analytic methods, when applied to correlation matrices, cannot be used to estimate unattenuated factor loadings. Presents a mathematical basis for the accurate estimation of such values when the disattenuated correlation matrix or the covariance matrix is used as input. Explains how the equations…

The difference in statistical power between the original Bonferroni and five modified Bonferroni procedures that control the overall Type I error rate is examined in the context of a correlation matrix where multiple null hypotheses are tested. Power differences of less than 0.05 were typically observed for the modified Bonferroni procedures. (SLD)

The general factor of mental ability ("g") may reflect general biological fitness. If so, "g"-loaded measures such as Raven's progressive matrices should be related to morphological measures of fitness such as fluctuating asymmetry (FA: left-right asymmetry of a set of typically left-right symmetrical body traits such as finger…

The treatment of covariance matrices given by McDonald (1974) can be readily modified to cover hypotheses prescribing zeros and equalities in the correlation matrix rather than the covariance matrix, still with the convenience of the closed-form Least Squares solution and the classical Newton method. (Author/RC)

Some suggestions for measuring marginal symmetry in agreement matrices for categorical data are discussed, together with measures of item-by-item agreement conditional on marginal asymmetry. Connections with intraclass correlations for dichotomous data are noted. (Author)