be able to accommodate the range of complexities that characterize both human­ human and human-machine communication. The chapters in this book are based on the papers that were presented at the workshop. They are presented in an order that is determined primarily by the specificity of the topics they address. The initial chapters are more theoretical in nature with an emphasis on formal approaches to communication. The middle chapters focus on particular application issues, such as the generation ofmultimedia documents and the role of planning in building systems to support human-human or human-machine interaction. The final few chapters consider more general issues relating to com­ munication, such as the influence ofsocial structure on, and the role of affect in communication.