RC - A PROFILE SIMILARITY COEFFICIENT INVARIANT OVER VARIABLE REFLECTION

As a measure of profile similarity, the product-moment r between variables suffers from the defect that its value varies with arbitrary decisions as to the direction in which variables are measured, for example, whether extraversion or introversion is scored high. A new correlation coefficient rc is invariant over reflection about m of any number of variables and has the descriptive properties of r but is generally smaller, thus facilitating Q-factor analysis using standard computer routines. Guilford's G index and Holley's H index are special cases of rc, which with r and Tucker's phi are special cases of rg, a general index of correlation via proportionality of paired deviations from constants. (PsycINFO Database Record (c) 2006 APA, all rights reserved). © 1969 American Psychological Association.