Orthogonal principal planes

Factor analysis and principal component analysis result in computing a new coordinate system, which is usually rotated to obtain a better interpretati on of the results. In the present paper, the idea of rotation to simple str ucture is extended to two dimensions. While the classical definition of sim ple structure is aimed at rotating (one-dimensional) Factors, the extension to a simple structure for two dimensions is based on the rotation of plane s. The resulting planes (principal planes) reveal a better view of the data than planes spanned by Factors from classical rotation and hence allow a m ore reliable interpretation. The usefulness of the method as well as the ef fectiveness of a proposed algorithm are demonstrated by simulation experime nts and an example.