Abstract
Citizen science projects, which entail scientific work undertaken by members of the public, have increased substantially over the last three decades. However, the credibility of such science has been questioned, especially with respect to its prospects for producing peer-reviewed publications, the principal means by which science is communicated and validated. We conducted a meta-analysis of 895 citizen science projects launched between 1890 and 2018. Three-quarters (674) did not produce a single peer-reviewed paper. The remaining 221 projects produced 2075 publications, although just five projects accounted for nearly half the publications. The average time from project launch to first publication was 9.15 years. Projects in health and medicine and astronomy were most likely to produce publications. Projects in biology (65.8% of all projects), computer science, and social sciences were least likely to publish their results. In conclusion, the "science" element of most citizen science projects is largely irrelevant as it is never validated or communicated. We propose reclassifying citizen science projects into two types: (i) Citizen Science, where the focus is on science, and participants essentially function as sampling devices; and (ii) Citizen Engagement, where the value lies more in citizen engagement than it does in citizen science.