Value-added estimates of teachers' contributions to student achievement have been criticized for bias relating to the sorting of students to classrooms. More recently, research has raised the possibility that sorting leads to differences in practice evaluation ratings between teachers of more or less disadvantaged and/or higher- and…

As states, districts, and schools transition toward more rigorous educator evaluation systems, they are placing additional weight on judgments about educator practice. Since teacher and principal observation ratings inherently rely on evaluators' professional judgment, there is always a question of how much the ratings depend on the particular…

Purpose: The article reports on a study of school leader decision making that examined variation in the validity of teacher evaluation ratings in a school district that has implemented a standards-based teacher evaluation system. Research Methods: Applying mixed methods, the study used teacher evaluation ratings and value-added student achievement…