This book addresses the question of whether and how currentcomputational approaches to communication can or might beable to accommodate the range ofcomplexities thatcharacterize both human-human and human-machinecommunication. The chapters in the book are based on papers presented at aNATO Advanced Research Workshop held in Italy in late 1990where an international group of computer scientists andcognitive scientists met to discuss theoretical and appliedissues concerning communication. The initial chapters aremore theoretical in nature with an emphasis on formalapproaches to communication. The middle chapters focus onparticular application issues, such as the generation ofmultimedia documents and the role of planning in buildingsystems to support human-human or human-machine interaction. The final few chapters consider more general issues relatingto communication, such as the influence of social structureon, and the role of affect in communication.