Cooperation is both a key concept to deal with complex design tasks and an ambiguous notion interpreted in a variety of ways. In particular, cooperation is considered from its behavioral aspects relating to the course of the dialogue (communication), and from a synchronizational viewpoint with respect to coordination issues. From the database point of view, the second perspective is more familiar, and is thus scrutinized to considerable detail. Especially, the dynamic aspects of interactions are of paramount interest for interactive, multi-user databases. In this paper, first some conceptual foundations on interaction in teams are established. Second, a new concept named conversational team-work is defined. Conversational team-work is a joint manner of data manipulation for dynamically interacting database users.<<ETX>>