Over the past decades there has been an increasing recognition of theneed to promote dialogue between science and society. Often this takes the formof formal processes, such as citizen’s juries, that are designed to allow the publicto contribute their views on particular scientific research areas. But there arealso many less formal mechanisms that promote a dialogue between science andsociety. This editorial considers science festivals and citizen science in this contextand argues that we need a greater understanding of the potential impacts of theseprojects on the individuals involved, both scientists and the public