 Research, Intervention and Collective Action Method: What Reciprocal Influences in Childhood Protection? 
Research Framework: This article is part of a participatory research in child protection, resulting in the collaboration of university and peer researchers in a process of inquiry, political consultation and collective mobilization. Objectives: It questions the reciprocal links of influence between research, interventions and collective action in childhood protection in France. Methodology: This article is based on data from the research journal and an analysis of the research process. Results: In this article, we argue that the participative research contribute to developing new forms of knowledge, by establishing new relationship between theory and practice, and new models of interactions between researchers, decision makers and users. We also underline the risk that this innovative analytical device will lose its critical purpose in its relationship with institutions seeking to incorporate criticism while reducing its scope. Conclusions: However, this work shows that research devices are modelled by support systems in a context where the participation of users becomes the cornerstone of legitimizing the utility of social work. In return, research can contribute to influencing support systems by developing new processes of knowledge co-production and recognition of places and roles of researchers, decision makers, children and young people concerned, making possible the emergence collective actions. Contribution: In the line of research interventions and research "with", this article contributes to reflection on the links between research and public action.