The Tennessee Value-Added Assessment System, known as TVAAS, is a statistical method used to measure the influence of a district, school, or teacher on the academic progress (growth rates) of individual students or groups of students from year to year. The concept behind TVAAS is that schools should “add value” every school year for each student, whether their starting point is above, at, or below grade level. The use of value-added assessment to measure “the impact that the teacher, school and school district have on the educational progress of students” was enacted in Tennessee statute in 1992 as part of the Education Improvement Act. State law requires annual estimates of teacher, school, and school district effects on student progress. This brief answers some questions about the state’s use of TVAAS.