For academics, collaboration is an important way to look at and discuss particular themes that are of personal and community interests. Inter-organizational collaboration distinctively offers the possibility for academics to look beyond the familiar and the known, and as such to develop further one’s professional identity and produce rich and creative academic products. The central interest of this PhD study is how communicative processes proceed in inter-organizational project groups, in which academics from different socio-cultural contexts meet and aim to create something collaboratively. Our research question is how diversity comes to the fore in negotiation processes in inter-organizational academic collaboration. Understanding this process enables grasping the challenge of dealing with diversity and to suggest how to facilitate project groups in their boundary crossing endeavor. The research question is explored by studying two inter-organizational collaboration projects. In both cases we identified the socio-culturally informed, and personal viewpoints that play a role in the collaboration and explored in what way these came to the fore during the negotiation processes. Both project groups were followed two years by means of video-taping and observing project meetings, interviewing project members individually, and collecting e-mail communication and documentation. The study of the first project group involves a European collaboration project with 14 academics located in five different countries. What this case illustrates, is that the diverse points of view have to be made explicit in order to play a role in collaborative work. For group participants, this means that they have to consider the particularity of the other person’s arguments. This can be done by questioning what it ‘is’ we are relating to, and focusing on the other as stranger. The second case study involves a Dutch collaboration project of 16 academics from different research groups. In contrast with the case in the first study, this project group comes to define the diversity as they explicate the diverse voices they aimed to advance and integrate. Despite this explicitation of and shared responsibility for the diverse positions, this case shows that diversity requires a long-term dialogical process involving actively construing and shifting between various ways of looking and categorizing the diverse elements in the project activity. In a final study, we sketch some implications that can be drawn from the two case studies of project groups. We came to conclude that managing and making use of diversity subsist in overcoming imprisonment in meaning and in exploiting meaning potential. Managing and making use of diversity seems to subsist in engaging project groups in a continuous process of redefining. By means of such a process one can overcome the bounded nature of one perspective by means of another perspective, and establish flexibility to adapt to new situations. In this last study, we consider in what ways information and communication technology meant to support collaboration, can facilitate groups to redefine. Besides these studies, this thesis includes a conceptual review of group cognition and