To address the invisibility of schools serving highest-need students, ACE Charter Schools, a network of schools serving highest-need students in San Jose, California, partnered with Education Analytics, the CORE Data Collaborative, and Public Impact to change the definition of school quality, making visible the success that schools are achieving with highest-need students. Section 1, the "School Needs Index," explains the methodology for measuring the extent of support that students need to thrive academically. By calculating a School Needs Index for each school, educators, policymakers, and the public can gain a clearer understanding of the level and type of support that each school's students need to succeed. Section 2, Success Measures, explains methods to apply the School Needs Index to identify schools achieving outstanding results with highest-need students. The report also includes a series of appendices providing additional information about the analysis and the technical details that will allow other researchers to replicate the methodology. The hope is that the methods presented in this working paper will be immediately useful to educators and the agencies that oversee schools, providing tools to improve understanding of schools' challenges and their successes. [This report was prepared for The National Campaign for Highest-Need Students.]