This book, Correlation Analysis in Chemistry: Recent Advances, is a sequel to our Advances in Linear Free Energy Relationships. t The change in the title is designed to reflect more accurately the nature of the field and the contents of the volume. The term LFER is still widely used, but it is often applied rather loosely to correlation equations that are not LFER in the restricted sense of a relationship involving logarithms of rate or equili brium constants on each side of the equation. The term "correlation analysis" seems to us more appropriate for the whole subject. The use of this term has compelled us also to introduce "chemistry" into the title; we have preferred not to prefix this with "organic" on the grounds that several areas of interest are not "organic chemistry" as usually understood, al though, of course, traditional applications of the basic relationships asso ciated with the names of Hammett and of Taft continue to be of interest. In the first volume we sought through our authors to provide a series of general articles covering the various aspects of the field as they seemed to us. Since the book was the first international research monograph in its field, each chapter, while giving prominence to recent developments, did not neglect earlier work, so that each article presented a comprehensive account of its own area.