Value-Added Studies in Education Are Best Described as

Value-added studies in education are best described as

A) A research design that seeks to hire excellent teachers at a low salary and determine how they fare in the classroom
B) A research design where students are randomly assigned to teachers' classrooms and the teachers of selected students are told that the IQ of each student in the room exceeds 130 and then determining if those teachers worked more effectively with the students
C) A statistical technique that uses student achievement data over time to measure learning gains and estimate the impact that teachers and schools have on student learning apart from family and socioeconomic background
D) A statistical technique that measures student achievement over time where students are told that selected teachers are "the best in the school" and other students are told their teachers "are among the worst in the school," and determining the effect on student achievement of the value students place on their teachers