This volume in the Lecture Notes of Artificial Intelligence represents the first book on human computing. We introduced the notion of human computing in 2006 and organized two events that were meant to explain this notion and the research conducted worldwide in the context of this notion. The first of these events was a Special Session on Human Computing that took place during the Eighth International ACM Conference on Multimodal Interfaces (ICMI 2006), held in Banff, Canada, on November 3, 2006. The theme of the conference was multimodal collaboration and our Special Session on Human Computing was a natural extension of the discussion on this theme. We are grateful to the organizers of ICMI 2006 for supporting our efforts to organize this Special Session during the conference. The second event in question was a Workshop on AI for Human Computing organized in conjunction with the 20th International Joint Conference on Artificial Intelligence (IJCAI 2007), held in Hyderabad (India), on January 6, 2007. The main theme of IJCAI 2007 was AI and its benefits to society. Our workshop presented a vision of the future of computing technology in which AI, in particular machine learning and agent technology, plays an essential role. We want to thank the organizers of IJCAI 2007 for their support in the organization of the Workshop on AI for Human Computing.