The purpose of this paper is to provide an in-depth critical analysis of the use and misuse of correlation coefficients. Various analytical and interpretational misconceptions are reviewed, beginning with the egregious assumption that correlational statistics may be useful in inferring causality. Additional misconceptions, stemming from…

That the jackknifing technique is superior to traditional techniques for assessing the external validity of statistical results of discriminant analysis is defended. Traditional approaches assessed include: (1) the empirical method, in which the discriminant function coefficients (DFCs) obtained in a given analysis are applied to predict group…

Both common factor analysis and components analysis are useful techniques for reducing the number of variables in a data set or for identifying underlying covariance structures that exist among a set of variables. Although researchers have for some years debated the appropriateness of selecting one of these methods over the other, components…

In 1994, the journal "Educational and Psychological Measurement" (EPM) instituted an editorial policy requiring authors to use technically appropriate language and methodological practices in their discussions of validity and reliability. To determine if this policy has had any effect on current publications, 150 validity and reliability…

This paper demonstrates how Q-methodology combines artistic and scientific procedures to allow social science researchers to develop and test theories about differences in persons. Q-methodology is based on factor analysis. In R-technique factor analysis, the most commonly used technique, variables define the columns and persons define the rows of…