"The author does a good job in explaining basic formal and mathematical concepts. … a useful text for psychologists and scientists from other fields that deal with similar data. The book covers a wide range of topics related to exploratory factor analysis and is useful to readers interested in that topic."—Statistical Papers (2014) 55"I must say that I am very happy that the author has taken the challenge to update and revise this precious book into the second edition. It will be an important source for decades to come. … there are good grounds for the new edition … it digs deep into the foundations of factor analysis … the topics are explained clearly, and mathematics is taught, as it is needed to understand a derivation of an equation or some procedure. … the book is worth having nearby … ."—International Statistical Review (2010), 78