Citizen science projects advance scientific inquiry by enlisting large crowds of volunteers to clean, code, and categorize large datasets in areas where humans still outperform machines. Though the usefulness of citizen science is no longer seriously in doubt, obstacles remain that prevent it from reaching its full potential. A lack of common standards for citizen science data projects makes it difficult to share or repurpose data; regulatory barriers inhibit federal agencies from using citizen science effectively; and the lack of a common repository of information on citizen science projects prevents researchers from taking advantage of what has already been learned. This grant supports efforts by the Commons Lab at the Woodrow Wilson International Center for Scholars to ease some of these barriers. Over the next two years, a team led by Anne Bowser will join with members of the citizen science community to spearhead a grassroots effort to develop common metadata standards; create a database of citizen science projects, develop a platform and API to facilitate citizen science data-sharing, examine the ethical and regulatory barriers to using unpaid volunteers in research projects, and conduct outreach to federal agencies and policymakers about the way in which citizen science can and is being used to further the aims of federal initiatives.