| Abstract: | A commonly used criterion for the number of factors to rotate is the eigenvalues-greater-than-one rule proposed by Kaiser (1960). It states that there are as many reliable factors as there are eigenvalues greater than one. The reasoning is that an eigenvalue less than one implies that the scores on the component would have negative reliability. I show here that this rule is the result of a misapplication of the formula for internal consistency reliability. I also present a formula for the reliability of a component; it depends on the eigenvalue and the reliability of the individual measures. (PsycINFO Database Record (c) 2010 APA, all rights reserved) |
