In accordance with the federal No Child Left Behind (NCLB) law of 2001, 100% of students were expected to become proficient on state assessments of reading and mathematics by the end of 2013-2014 academic year. Schools that consistently failed to meet the NCLB's Adequate Yearly Progress requirements were subject to penalties. In 2011, the U.S. Department of Education invited each State educational agency (SEA) to request flexibility regarding specific requirements of the NCLB in exchange for "rigorous and comprehensive State-developed plans designed to improve educational outcomes for all students, close achievement gaps, increase equity, and improve the quality of instruction." In order to receive flexibility from the NCLB Adequate Yearly Progress requirements, states had to develop and implement "high-quality teacher and leader evaluation and support systems that are based on multiple measures, including student growth as a significant factor and other measures of professional practice." At the time of the publication of this brief, most states received flexibility waivers. Currently, these states are at different stages in the process of implementing their teacher evaluation and support systems. Many of them use Value-Added Models (VAM) similar to those used in Florida, while others use the Student Growth Percentile (SGP) approach. In this brief the authors compare three methods of teacher evaluation: (1) the State system employing value-added models; (2) a district-level procedure using single-level regression; and (3) a common alternative approach utilizing student growth percentiles. All three methods start by constructing predictions of student test performance based on prior achievement data and student characteristics. At this basic building block level, all three approaches produce virtually identical results. As the methodologies diverge in techniques of aggregation, teacher-level and school-level summary indices begin to separate, but remain remarkably comparable.