Knowledge creation and sharing in organizations is most often assumed to involve direct interactions. It is true that the creation of shared knowledge is really only feasible when people share and improvise local practices, through membership of the same workgroup. However, organizational innovation frequently involves a range of different stakeholder groups, spanning many different domains of professional practice. Definitions of "valid" and "relevant" knowledge become subject to negotiation and joint improvisation. This is reflected not only in discourse, but in the resources that mediate boundary-spanning interactions. This exploratory study analyzes how technical and organizational resources provided mediation of knowledge between different work-groups and how different forms of mediation led to the adaptation of the information systems that they defined and use in common.