This article contributes to reflective practice amongst scientists who engage with citizens in the digital public sphere, by exploring the scientists' experiences and underlying perspectives on their role repertoires in online science-society interactions. Semi-structured interviews were held with 26 European scientists to investigate their focus and contribution in boundary interactions, perspective on appropriate model of science communication, and activities, outputs and addressees in the digital public sphere — together comprising a role repertoire. The intended role of scientists often did not match with their deployed repertoire in online interactions with citizens. Participants were left with the feeling that the digital public sphere provides hollow interactions, devaluates scientific expertise or even represents a hostile environment. In order to capitalise on the promise of the digital public sphere for constructive interactions with a diverse public, a reflective practice is needed that aligns scientists' intended contribution to science-society interactions with the scientists' perspective and deployed online repertoires