By supporting the adoption of evidence-based PreK -- 3 policies and practices, The McKnight Foundation's Pathway Schools Initiative seeks to dramatically increase the percentage of proficient third-grade readers in high need schools. To support real-time learning, decisionmaking, and improvement of new practices, programs, and policies, The McKnight Foundation has engaged Pathway Schools Initiative leaders in a developmental evaluation (DE) of highpriority questions of practical interest. DE is a collaborative effort that begins with identification of a question about challenges or new approaches to meeting students', teachers', and other critical stakeholders' needs. DE then supports continuous improvement by gathering data and offering rapid, relevant feedback to the initiative leaders, who develop action plans based on the implications of the findings. The DE team was composed of two to three leaders from each of the participating schools and districts1 and staff members from McKnight, the Urban Education Institute (UEI) at the University of Chicago, SRI International, and Child Trends. This learning brief summarizes the team's first DE question, research methods, findings, and action plans. The team intends to address two to three DE questions each year.