This paper examines the challenges of participation in large-scale public projects. Taking its offset in a case-study of the development of a new public multimedia library, the paper discusses methods and values of Participatory Design in the face of the challenges that a project of this scale entails. These challenges concern how to address and manage a heterogeneous group of stakeholders and end-users, how to inform stakeholders and establish participation as a relevant activity, the development of new techniques and technologies to scaffold participation, and the interplay between iterative development and institutional transformation.
