In an effort to improve high school graduation and college enrollment rates among students who are Black, Latino, or experiencing poverty, the Bill & Melinda Gates Foundation established the Networks for School Improvement (NSI) initiative and awarded five-year grants to intermediary organizations to develop networks of school teams that work together using continuous improvement (CI) processes. This report details the sample, data, and methodology used in the interim analysis of 25 of these networks to understand how they operate and factors that contribute to strong networks. Data collection activities consisted of a survey of CI team leaders (the Team Connections Survey), interviews with intermediary and district staff, focus groups with CI team members, observations of network events, and a survey of network participants (the Partners for Network Improvement Network Health Survey). This report presents information on the NSI grantees and the instruments used to conduct the surveys, interviews, and focus groups.