How to measure the impact of citizen science on environmental attitudes, behaviour and knowledge? A review of state-of-the-art approaches

Abstract The effects of citizen science are wide ranging, influencing science, society, the economy, the environment, as well as individual participants. However, in many citizen science projects, impact evaluation is still overly simplistic. This is particularly the case when assessing the impact of participation in citizen science on the environmental attitudes, behaviour and knowledge of citizen scientists. In an attempt to bridge the gap between the state of the art in relevant scientific fields and citizen science, this systematic literature review identified best practices and approaches in the field of environmental psychology for measuring environmental attitudes, behaviour and knowledge. From the literature, five relevant and validated approaches were identified that can be used to measure changes in attitudes, behaviour and knowledge in citizen science projects. This would allow for improved understanding of the impacts of citizen science, as well as for improved project evaluation as a whole.