The working paper reviewed here seeks to assess the extent to which “No Excuses” charter schools raise student achievement in English language arts and math and thereby close the achievement gap. The paper defines such schools as having: a) high academic standards, b) strict disciplinary codes, c) extended instructional time, and d) targeted supports for low-performing students. From their meta-analysis of 10 quasi-experimental studies , the authors concluded students who attended No Excuses charter schools had average achievement gains of 0.16 standard deviations in English language arts and 0.25 in mathematics. While conceding that charter schools with lotteries and No Excuses charter schools are not representative of all charter schools, the authors did not address whether or how students who apply to lottery charter schools might not be representative of all charter school students. They also did not address the possible relevance of student attrition for the individual studies’ findings and their own analysis. As a result, the claim that No Excuses schools can close the achievement gap substantially overstates their findings. Moreover, the report’s relatively small sample of schools concentrated in Northeast Coast cities suggests the current research base is too limited to draw conclusions about the effectiveness of No Excuses charter schools.