Museums and the Online Archive of California II User Evaluation (MOAC II) is a two-year study funded by the Institute of Museum and Library Services (IMLS) that seeks to evaluate the needs and behaviors of four key user constituencies of MOAC: 1) K-12 teachers; 2) university students; 3) academics in the humanities and social sciences; and 4) museum professionals, librarians, and archivists, with the goals of generating recommendations for improving the usability and value of MOAC as well as encouraging its use in research and learning contexts. The study seeks to contribute to the continued enhancement of MOAC, first conceived in 1997, a museum/library collaboration that is building aggregated, publicly accessible collections of digitized museum content and their metadata. This paper first reviews the development of MOAC, with a particular emphasis on the nature of its contents as well as its metadata infrastructure. It then discusses the triangulated research design that is being applied by the study.