Spearman's "law of diminishing returns" or SLODR refers to a decrease in "g" saturation as ability level increases. SLODR has been demonstrated in a number of intellectual batteries but several important aspects of the phenomenon are not yet well understood. We investigated the presence of SLODR in the Kaufman Assessment…

I describe an assignment for personality psychology or introduction to psychology classes in which students used the Five Factor Model of personality to analyze the personality of entertainer Johnny Carson through his The New York Times obituary. Students evaluated this assignment highly: A majority indicated that the assignment was interesting,…

Some authors have suggested that sample size in covariance structure modeling should be considered in the context of how many parameters are to be estimated (e.g., Kline, 2005). Previous research has examined the effect of varying sample size relative to the number of parameters being estimated (N:q). Although some support has been found for this…

All parametric analysis focuses on the "synthetic" variables created by applying weights to "observed" variables, but these synthetic variables are called by different names across methods. This paper explains four ways of computing the synthetic scores in factor analysis: (1) regression scores; (2) M. S. Bartlett's algorithm…

Higher order factor analysis is an extension of factor analysis that is little used, but which offers the potential to model the hierarchical order often seen in natural (including psychological) phenomena more accurately. The process of higher order factor analysis is reviewed briefly, and various interpretive aids, including the Schmid-Leiman…

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

The Dutch Identity is a useful way to reexpress the basic equations of item response theory (IRT) that relate the manifest probabilities to the item response functions (IRFs) and the latent trait distribution. The identity may be exploited in several ways. For example: (1) to show how IRT models behave for large numbers of items--they are…

Distributional characteristics of the measure of sampling adequacy (MSA) were investigated in sample correlation matrices generated from multivariate normal populations with covariance matrix equal to the identity. Systematic variation of sample size and number of variables resulted in minimal fluctuation of the overall MSA from .50. (Author/RC)

Investigates the relation between factor score estimates, principal component scores, and image scores. The three methods compared are maximum likelihood factor analysis, principal component analysis, and a variant of rescaled image analysis. (RC)

A Fortran IV program is presented which will cross-correlate least squares estimated factor scores across separately factor analyzed variable domains without the tedious necessity of actually calculating the factor scores. (RC)

TMFA, a FORTRAN program for three-mode factor analysis and individual-differences multidimensional scaling, is described. Program features include a variety of input options, extensive preprocessing of input data, and several alternative methods of analysis. (Author)

Extension analysis allows for the investigation of relationships between factors from a core set of variables and the variables from an additional, extension set. This frequently results in obtaining negative residual variances, called Heywood cases. Procedures for checking for that problem are presented here. (Author/JKS)