This chapter identifies some of the fundamental conditions and factors that affect collaborative project work on the Net. Understanding them is fundamental to developing key qualities in Net-based collaborative learning such as confidence, reliability, and trust. We argue that: (1) Collaboration and social interaction develop in continuous oscillations between abstract and meaningful frames of reference as to time and place. (2) Such oscillations condition the creation of a double identity of writer and author modes in social interaction. (3) Collaborative work creates an ever-increasing complexity of interwoven texts that we have to develop strategies for organizing. (4) One such important strategy is the negotiation of roles among the participants. Having established this theoretical framework, we discuss how to deal with these conditions in an actual Net-based learning environment, the Master of Computer-Mediated Communication program at Roskilde University, Denmark.