Scientific research is undergoing a slow transformation characterized by openness to civil society and transparency of its methods and findings. This is being driven by a growing commitment to sustainable development and society’s involvement in critical thinking and decision-making. Through many projects, from citizen science promoted by associations and institutions, to research promoted by the European Commission in Mobilizing Mutual Learning projects, the link between science and citizens is slowly changing. The citizen is now recognized as a bearer of valid intrinsic knowledge suitable for research material. Science centres and museums can become effective mediators, encouraging the circulation of knowledge between scientists and citizens. The aim of this session is to give voice to a variety of positions, both for and against citizen participation, and come away enlightened about this new approach to science.