Abstract.  The overall project aims to establish a dialogue between normative democratic theory and research on policy formulation and implementation. This introductory article first notes the growth of various participatory and deliberative procedures in policy making, portrays the context of this growth and justifies the cases selected. It then presents the conceptual framework used for the study of these procedures, which mainly draws on participatory and deliberative democratic theory and the literature on the shift from ‘government’ to ‘governance’. Based on this conceptual framework, the article focuses on four research questions the authors consider particularly important for the assessment of the contribution of the devices under scrutiny to democratic and effective decision making: questions of openness and access (input-legitimacy); questions regarding the quality of deliberation (throughput); questions of efficiency and effectiveness (output-legitimacy); and the issue of their insertion into the public space (questions of transparency and accountability).