The 37 expository articles in this volume provide broad coverage of important topics relating to the theory, methods, and applications of goodness-of-fit tests and model validity. The book is divided into eight parts, each of which presents topics written by expert researchers in their areas.   Key features include:   * state-of-the-art exposition of modern model validity methods, graphical techniques, and computer-intensive methods   * systematic presentation with sufficient history and coverage of the fundamentals of the subject   * exposure to recent research and a variety of open problems   * many interesting real-life examples for practitioners   * extensive bibliography, with special emphasis on recent literature   * subject index   This comprehensive reference work will serve the statistical and applied mathematics communities as well as practitioners in the field.