—Citizen science is a form of research collaboration involving members of the public in scientific research projects to address real-world problems. Often organized as a virtual collaboration, these projects are a type of open movement, with collective goals addressed through open participation in research tasks. We conducted a survey of citizen science projects to elicit multiple aspects of project design and operation. We then clustered projects based on the tasks performed by participants and on the project’s stated goals. The clustering results group projects that show similarities along other dimensions, suggesting useful divisions of the projects.