ABSTRACT
This chapter considers some methods simpler than the complete centroid method, some methods more complex than the principal-axes method, and some methods based on models which are different from the usual linear model of common-factor analysis. The principal axes method is the method of choice for initial factoring. It requires the use of an electronic digital computer for all but very small problems and, because computers are generally available, it is likely to be used even with small correlation matrices as well as with larger ones. The principal-axes method gives a least-squares solution. The sequences of operations for the complete principal-axes method, the centroid method, and the diagonal method are all rank-reducing sequences. The computing procedures for alpha factor analysis and image factor analysis are both somewhat more complicated than are those of principal-axes analysis, approaching in complexity those of the maximum-likelihood and minres methods.
