This article offers a retrospective glance at four experiences of participant observation regarding various participative devices in the realm of urban planning in Brussels. The authors question the relationships between the researchers involved in these experiments and other stakeholders, including associations. Based on the sociology of Norbert Elias, this paper aims at thinking about shifting configurations formed by the actors and the involvement/detachment balance formed by these experiences. As for the researchers, being involved or participating would indeed signify a kind of self-detachment, helping to better understand the realities of participation in Brussels and the other actors’ standpoints. Starting with the empirical material, the authors also investigate the impact of their own participation on the research and on the participatory device and its outcome.