Traditionally, qualitative research is small in scale, involving no more than a few professional researchers and a couple of dozen participants, with the largely academic goal of contributing to generalized knowledge. In this paper, we contribute a framework for citizen social science, asking why, if, and how qualitative research might be undertaken on a larger scale, involving and empowering non-professional researchers, and addressing public issues. We answer this question using insights from research we have led, involving: first, fieldwork in disadvantaged communities by three separate years of public policy students, and second, over 100 volunteers and activists as researchers. Drawing on a review of the literature and our own experiences we speak to the challenges and suggest practical methods for conducting a new form of citizen social science: scaled, participatory, and public qualitative research.