Chicago's "multi-grade" charter high schools (those that include middle school grades) appear to be increasing students' rates of graduation and college entry. The overall performance of Chicago's charter schools in raising student test scores is approximately on par with that of traditional public schools in Chicago. Charter schools in Chicago are not having major effects on the sorting of students by race, ethnicity, or achievement. [This research brief describes work documented in "Achievement and Attainment in Chicago Charter Schools" by Kevin Booker, Brian Gill, Ron Zimmer, and Timothy R. Sass, 2008.]