From the involvement of citizens as excavators and re-enactors to the co-organisation of research campaigns and outreach activities, public participation in archaeology has become a well-represented practice, fully incorporated into European and national cultural policies. Encounters between archaeologists and citizens are considered as the basic unit of participative dynamics. Each encounter differs from the other: it can happen at the excavation fence and develop there, next to trenches, pits and walls. Or it can happen as a formal meeting between archaeologists and members of local institutions, in an official venue. Encounters may end when the time is up – once concluded a guided tour – or eventually turn into long-lasting collaborations and even friendships.

This paper will unfold the participation dynamics of long-lasting encounters that shaped the project ’Uomini e cose a Vignale’ (People and Things at Vignale), a community archaeology project tied to the ongoing excavation at the Roman site of Vignale (Tuscany, Italy). The contribution proposes an original evidence-based operational workflow to facilitate the evaluation of the dynamics of participation in ongoing excavations. Based on a flexible set of tools, analyses, and visualisation boards, the workflow can provide a broad range of information about public participation, informing the daily practice of fieldwork and the development of community projects.