The MET project is based on 2 premises: First, a teacher's evaluation should depend to a significant extent on his/her students' achievement gains; second, any additional components of the evaluation (e.g., classroom observations) should be valid predictors of student achievement gain. Student achievement was measured in 2 ways through existing state assessments, designed to assess student progress on the state curriculum for accountability purposes, and supplemental assessments, designed to assess higher-order conceptual understanding. The supplemental assessments used were Stanford 9 Open-Ended Reading Assessment in grades 4 through 8, Balanced Assessment in Mathematics (BAM) in grades 4 through 8, and the ACT QualityCore series for Algebra I, English 9, and Biology. Close to 3,000 teacher volunteers from across the following 6, predominantly urban, school districts participated in the MET project: Charlotte-Mecklenburg Schools, Dallas Independent School District, Denver Public Schools, Hillsborough County Public Schools, Memphis City Schools, and the New York City Department of Education. Participants teach math and English language arts (ELA) in grades 4-8, Algebra I, grade 9 English, and high school biology.