In this technical appendix, we describe our data sources and document the quantitative and qualitative methods we used to evaluate characteristics of California's arts and cultural nonprofit organizations and their host communities. We integrated quantitative data from five main sources, each with limitations and advantages, from which we made requisite correcting adjustments. By carefully designing three key indicator variables -- budget size, organization focus area (mission and/or artistic discipline), and region -- we assessed how arts and cultural organizations vary across California. To make use of the rich data available from the California Cultural Data Project, we investigated how well the data represent the entire landscape of nonprofit arts and cultural organizations in California. Based on the results, we designed a method for weighting the Cultural Data Project data to improve estimates. To explore how Californians' arts participation compares with the rest of the U.S. and varies across large metros in the state, we used data from the National Endowment for the Arts' Survey of Public Participation in the Arts. To investigate how arts and cultural organizations reflect and vary by the characteristics of the communities in which they are located, we compiled and analyzed data from the U.S. Census and other supplemental sources. For estimating the economic impact of California's arts and cultural organizations, we used the Impact Analysis for Planning input-output model and data for the state of California. This appendix also covers methodologies used in our interviewing work. To illustrate special features of California's smaller arts and cultural organizations and the challenges they face, we used data from interviews with organizations that are typical of those underrepresented in other data sources. Our careful approach integrates the best available data sources to shed new light on California's nonprofit arts and cultural ecology and the cities, towns, and communities in which it is embedded.