The key idea of the book is that scientific and practical advances can be obtained if researchers working in traditions that have been assumed to be mutually incompatible make a real effort to engage in dialogue with each other, comparing and contrasting their understandings of a given phenomenon and how these different understandings can either complement or mutually elaborate on each other. This key idea applies to many fields, particularly in the social and behavioral sciences, as well as education and computer science. The book shows how we have achieved this by presenting our study of collaborative learning during the course of a four-year project. Through a series of five workshops involving dozens of researchers, the 37 editors and authors involved in this project studied and reported on collaborative learning, technology enhanced learning, and cooperative work. The authors share an interest in understanding group interactions, but approach this topic from a variety of traditional disciplinary homes and theoretical and methodological traditions. This allows the book to be of use to researchers in many different fields and with many different goals and agendas.