Louis E. Guttman (1916–1987)

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45742/1/11336_2005_Article_BF02294129.pd

Comment on a note on a base-free measure of change

change scores,

Obtaining squared multiple correlations from a correlation matrix which may be singular

A theorem is presented relating the squared multiple correlation of each measure in a battery with the other measures to the unique generalized inverse of the correlation matrix. This theorem is independent of the rank of the correlation matrix and may be utilized for singular correlation matrices. A coefficient is presented which indicates whether the squared multiple correlation is unity or not. Note that not all measures necessarily have unit squared multiple correlations with the other measures when the correlation matrix is singular. Some suggestions for computations are given for simultaneous determination of squared multiple correlations for all measures. © 1972 Psychometric Society