Although virtual citizen science projects have the potential to engage large networks of people in science research, seeding and maintaining such networks can be difficult. A feature of successful projects is that they have well-motivated volunteers. What makes volunteers motivated rather than apathetic? In this paper we focus on projects that contribute to psychology research, which we term ‘citizen psych-science’. This differs from typical citizen science because volunteers are asked to contribute themselves as data. We describe research studies that we conducted with Errordiary – a citizen psych-science project where volunteers tweet about their everyday experiences of human error. These studies were: (1) an interview study, to explore the motivations of eight Errordiary volunteers; and (2) three focus groups, to explore the potential of attracting new communities to Errordiary. We found that the personal nature of the data can influence participation in positive and negative ways. We suggest several factors that scientists need to consider when encouraging citizen psych-science volunteers to contribute their personal experiences towards research
