An index for comparing the magnitudes of the observed correlation coefficients to the partial correlation coefficients. If the sum of the squared partial correlation coefficients between all pairs of variables is small when compared to the sum of the squared correlation coefficients, it is close to 1. Small values indicate that a factor analysis may not be a good idea, since correlations between pairs of variables cannot be explained by the other variables. Kaiser describes values in the 0.90's as marvelous, in the 0.80's as meritorious, in the 0.70's as middling, in the 0.60's as mediocre, in the 0.50's as miserable, and below 0.50 as unacceptable.
