The document discusses value-added assessment, which measures student growth and teacher effectiveness. It aims to provide teachers with diagnostic data to improve instruction. Value-added models require assessments that closely match curricula, can detect a range of student growth, and are reliably measured. The goal is for teachers to use data to increase all student achievement through differentiated instruction focused on individual growth. Research shows teacher effectiveness varies more between teachers than other factors and is the strongest influence on academic growth. Highly effective teachers ensure all students achieve and make excellent gains across achievement levels.