From Edutopia: MC2 (Metropolitan Cleveland Consortium) STEM High School is a year-round public school in Cleveland, Ohio, where instruction is through interdisciplinary project-based learning, and the focus is on providing students with an integrated curriculum that is informed by real-world experiences. The school uses a mastery system for assessment in grades nine and ten in lieu of the traditional A-F system. This means that students must demonstrate competency at 90 percent or better in order to receive an “M” for mastery on any given benchmark task, and they must achieve mastery in order to receive credit. In setting such a high bar, the system clearly defines expectations and demands top academic performance.