Participedia is an open global knowledge community for researchers and practitioners in the field of democratic innovation and public engagement. It represents an experiment with a new and potentially powerful way to conduct social science research: crowdsourcing data on participatory processes from researchers and practitioners from all over the world and making that data freely available for analysis. This paper reflects on the potential of Participedia to realize its aim of answering the basic research questions: what kinds of participatory processes work best, for what purposes, and under what conditions? Initially the paper reviews the data model that informs Participedia and the types of comparative analysis it might enable. An indicative analysis draws on the Participedia data to explore the relationship between aspects of institutional design (including facilitation, forms of interaction and decision methods) across a range of democratic innovations represented on the platform. The study offers important insights on institutional design, but also on the challenges of crowdsourcing reliable data from disparate communities.