The need to understand decision-making processes and develop individual decision-making skills is vital in modern societies. Increasingly, however, decisions are being made in a group context where the study of individual decision-making has limited utility. When people gather in a group a new entity is created. The contributors to this volume examine the importance of various factors to decision-making, including; membership characteristics, the nature of the task, group cohesiveness, size, channels of communication, and leadership.