The limits of numerous agricultural systems developed on principles set after the Second World War are increasingly highlighted. Meanwhile, agricultural and food systems associated with agroecological principles are progressively institutionalized in various countries. Whereas a dominant research production by agronomists consists in deduction of "agroecological practices" from fundamental agroecological principles, a gap remains between those principles and the specific management actions on farms that allow to build new agroecological framing systems. In this study, we stem from an analysis of management actions in 8 different case studies corresponding to farmers' collectives engaged in an evolution of their practices towards agroecology. We review the agroecological scientific literature in order to identify shared principles and system properties deduced from them, that we iteratively compared to the practices implemented by farmers, making the transition in our case studies. Our proposal is then to describe agroecology "in the making" as 4 interconnected ways of acting, each corresponding to specific relations between management actions and the systems' properties. Lastly, the analysis of agroecology from the actors' management practices allows us to support a new viewpoint about a research agenda for agronomists, giving reflexive benchmarks to relocate research activities within the institutionalization dynamics of agroecology.