This article focuses on participatory research to understand, support and promote the implementation of skills assessment in Cycle 3 within a strengthened priority education network. The research falls within the theoretical and methodological framework of ergonomic analysis of teachers’ activities in their workplace and is enriched by a didactic analysis aimed at identifying the knowledge in circulation related to the tools implemented in skills assessment. Analysis of the results shows that the evaluation systems and their use(s) are characterized by the (...) massive recourse to external resources, the time-consuming construction of new tools, and the enhancement of behavioural and cross-curricular skills to the detriment of disciplinary knowledge. The difficulty of establishing continuity in the students’ pathways due to different professional cultures and sometimes dissonant prescriptions between network primary and middle schools is obvious. The discussion questions the conditions of implementation of prescriptions relating to skills assessment and the articulation of ergonomic and didactic approaches within participatory research. (shrink)