Multivariate Statistical Techniques in Neuropsychology: II. Comparison of Number of Factors Rules with the Motor Scale of the Luria-Nebraska Neuropsychological Battery.

Discusses the relative advantages of statistical rules, mathematical models, and empirical methods in deciding the appropriate number of factors to be extracted in a factor analysis. The use of these approaches is illustrated using data from 125 normals and 375 brain-damaged and psychiatric patients on the Motor scale of the Luria-Nebraska Neuropsychological Battery. It is recommended that researchers accept a slightly larger number of factors rather than omit a possibly substantive factor and that at least 2 of the following 3 rules be used: scree test, parallel analysis, and percent variance. (15 ref)