Citizens, amateurs, volunteers: Conceptual struggles in studies of citizen science

The goal of this literature review is to bring together the different concepts, respective definitions and perspectives that have been used to study the participation of non-professionals in scientific activities. We start by presenting a short definition of citizen science and the perceived benefits of such approaches to the production of scientific knowledge. We then clarify the difference between today’s citizen science projects and their ancestors in the field sciences by highlighting technological and social changes. This is followed by a short discussion on typologies of citizen science projects and a description of “contributors,” considering the different terms used to identify them as well as the meaning assigned to these different semantic choices. The issues of expertise and the role of different forms of knowledge are then addressed, leading to a discussion on the quality of the contributions. Finally, we have a look at what has been written on the motivations of contributors.