Following a review of prior work, the paper presents a model of organizational memory. Relying on structuration theory for its development, the model overcomes some of the problematic dualisms of conventional approaches (i.e., subjecUobject, social/technical, abstract/concrete). According to the model, co-memory (for collective memory) consists of rules and resources that recursively mediate both interactivity and structure in organizations. The model provides the basis for a taxonomy of existing and projected IT-based co-memory systems. Four classes of co-memory systems are described: transactional, managerial, strategic, and team. An analysis of driving trends concerning people, structure, and technology is used to project four scenarios for organizations in 2001: bureaucracy, factory, affiliation, and infocracy. Co-memory systems that can be expected in each scenario are discussed. Predictions indicate that a mnemonic sh