What should citizens understand about science to participate in democratic life? Against the prevailing approach, we argue that “what” a public understanding of science is about strongly depends on the specific epistemological nature of the science related issues considered in different contexts and circumstances. We identify three specific categories of such issues and show how, equally, specific models of public understanding are required to address them. Only by endorsing such an alternative approach will citizens arguably be able to form sound opinions about those very issues, as well as to discuss and deliberate rationally about them.

Given the importance of the issue of scientific objectivity in our democratic societies and the significant development of citizen science, it is crucial to investigate how citizen science may either undermine or foster scientific objectivity. This paper identifies a variety of epistemic risks and benefits that participation of lay citizens in scientific inquiries may bring. It also discusses concrete actions and pending issues that should be addressed in order to foster objectivity in citizen science programs.