Exploratory Factor Analysis with SAS

The Magic of Rotation

Unrotated results from a factor analysis—as presented in Chapter 3—are not easy to interpret. Factor loading plots can help, but they can still present a rather confusing picture, particularly if there are more than two factors! Rotation was developed not long after factor analysis to help researchers clarify and simplify the results of a factor analysis. Indeed, early methods were subjective and graphical in nature (Thurstone, 1938) because the calculations were labor intensive. Later scholars attempted to make rotation less subjective or exploratory (e.g., Horst, 1941), leading to initial algorithms such as quartimax (Carroll, 1953) and varimax (Kaiser, 1958). Although varimax was introduced early on, it is still one of ...