From data to belonging: citizen science, urban friction, and institutional response in Siena

This article examines citizen science as situated urban politics in Siena, Italy, through two initiatives engaging students, residents, migrants, volunteers, and researchers in documenting everyday urban life and river ecosystems. Drawing on ethnographic engagement, data walks, and interviews, we argue that citizen science produces more than data: it becomes a relational practice through which participants negotiate belonging, enact presence, and challenge epistemic hierarchies in urban governance. The article shows how digital platforms both enable participation and act as epistemic gatekeepers, making friction a diagnostic and transformative force for more responsive urban knowledge practices.