Against the background of critique in public engagement scholarship on new and emerging science and innovation, this article engages with the methodological and conceptual challenges of making anticipatory knowledge. Adopting a science and technology studies perspective, a public engagement methodology is presented aimed at anticipating the kinds of possible and plausible worlds that novel science and technology bring into being. Drawing on six empirical social science research projects using focus groups, design criteria are explicated on context, framing, moderation, sampling, analysis and interpretation. A feature of the methodology lies in the assembly of emergent collectives and identities that are constituted to negotiate endogenously public meanings, concerns and priorities. I reflect on the potential of such processes to reconfigure dominant policy narratives, the role of the social scientist in mediating such processes and the politics of making anticipatory knowledge.