This volume was conceived as a tribute to Fred Fiedler in honor of his fortieth year of research and scholarship in the study of leadership and organizational effectiveness. Fiedler's contributions to this field have been of such magnitude that the term paradigm shift does not seem out of place in describing them. As Harry Triandis points out in his chapter in this book, the study of leadership can be fairly divided into before and after Fiedler's introduction of contingency theories. The realization that leadership effectiveness depends on the interaction of qualities of the leader with demands on the situation in which the leader functions made the simplistic one best way approaches of earlier eras obsolete. The implication of contingency notions spread like sonic waves throughout the field of organizational studies.