When a community embarks on initiatives to improve population-level outcomes, one of the first orders of business is to designate the names and geographic boundaries of the community as a whole and of the specific neighborhoods within the community. Some areas of L.A. engaged residents in a boundary-definition process to ensure that the neighborhood boundaries had meaning for residents as they sought to make changes in their family and neighborhood spheres of influence. Other areas of LA are using predefined boundaries, often established by local governments. Collecting population data to represent all neighborhoods in the community is the goal, but the strategy for reaching that goal varies by community. With sufficient buy-in from key leaders and a clear plan for reaching all the elementary schools that serve the community, communities can achieve full EDI participation of the population quickly. Some communities begin by targeting a subset of schools or neighborhoods and then expand data collection over time. The EDI data reported in this brief are from the 19 L.A. County neighborhoods that achieved at least 70 percent participation as of July 2013, along with aggregate EDI data for L.A. County, Orange County and the U.S. (author abstract)