The growing field of Group Decision and Negotiation is best described as the empirical, formal, computational, and strategic analysis of group decision-making and negotiation, especially from the viewpoints of Management Science and Operations Research. The topic crosses many traditional disciplinary boundaries. It has connections to business administration and business strategy, management science, systems engineering, computer science, mathematics, and law, as well as economics, psychology, and other social sciences. This defining handbook provides an up-to-date reference on new approaches to the principles and practice of negotiation, group decision-making, and collaboration, including the origins, development, and prospects of electronic negotiation, as well as the associated development of on-line or computer-based arbitration systems. It also provides a current and comprehensive reference on how traditional issues in negotiation, such as knowledge, language, strategy, fairness and justice, have been transformed by technology. Until now, this advancing field has lacked a comprehensive, accurate, reliable, and readable reference. This handbook satisfies this need, and is set to become the major reference in the field.