WestEd has made substantial progress on the evidence of promise study for Clark County School District's (CCSD) 2017 Magnet Schools Assistance Program (MSAP) grant. WestEd collected the necessary student-level test score, course credit, and demographic data from CCSD for the study to identify statistically significant or substantively important effects of the MSAP-funded schools on student outcomes. For this report (which is the third interim evaluation summary report), WestEd added additional findings using the same Measures of Academic Progress [MAP] assessments from 2019-20 to the second interim report based on a randomized controlled trial (RCT) that relied on the lottery of one school in the study that was substantially oversubscribed. The findings from the RCT, which is a more rigorous design than the quasi-experimental designs (QEDs), replicated the positive and statistically significant impact on a large group of 6th graders' mathematics achievement found by the QED. Prior to developing the final summary report for the evidence of promise study, WestEd will explore ways to rigorously evaluate the impact of the MSAP-funded magnet schools on reducing, eliminating, or preventing minority group isolation that could meet WWC Design Standards.