The objective of ISEED is to identify, through an analysis of a variety of types of, and experiments in, public engagement on science-related questions and activities, generalizable characteristics and conditions that cultivate active and productive citizen participation in public deliberation. The aim is to construct a novel concept of ‘deliberative participation’ designed to enhance both the quality and the legitimacy of political decision-making, by focusing on the importance of knowledge-based deliberation. ISEED will build on and extend existing experience in the field of citizen science to explore the conditions under which participative and deliberative practices can be successfully implemented for the purpose of building forms of knowledge-based democratic governance complementary to political representation in democratic societies. ISEED combines theoretical analysis, empirical research, and small-scale experiments. It will reassess the role of the public sphere to include a novel notion of deliberative participation in a plurality of publics and counter publics. It will empirically explore how current practices of citizen participation in science can offer innovative methods to confront and overcome a number of current obstacles faced by democratic participation and decision making. It will develop a new tool to describe styles of argumentation in traditional and digital media and analyze the role of emotion and reason in polarised debates on contemporary scientific issues. The ISEED consortium, committed to multi and inter-disciplinary research, aims to deliver scalable results to foster deliberative democratic processes in Europe and other knowledge societies.