The "Value-Added” assessment model aims to project a student’s test score growth over time, after attempting to adjust for poverty and other factors known to affect achievement. Look at all of a teacher’s student scores and you’ll see how effective that teacher is, the theory goes.
But life is more complicated than a value-added algorithm. In real life, some teachers get students who are harder to reach for all sorts of reasons. They may have an extra share of problems with language, motivation, disabilities, or classroom discipline. And each year, the students change. So let’s ask the research. Can you tell a star teacher from an ineffective one by looking at their value-added scores?
In a word, no.
A simple video that helps explain Value-Added:
For more information on Value-Added, see the following links:
Louisiana Department of Education presentation on the "Value-Added" Assessment Initiative
Barriers to Effective Teacher Evaluation: The False Promise of Test Score Accountability
Some advocates of teacher evaluation reform suggest that student test scores are an appropriate measure of teacher quality and effectiveness, but student performance and teacher performance are NOT the same thing. Suggesting that one person's job performance is casually responsible for another person's outcome requires stronger inferences and evidence. This evidence has not been produced to date.
Using student outcomes to measure teacher practice is problematic for many reasons:
1. It assumes that the teacher controls all student behaviors that impact achievement, such as attendance, studying, eating well, sleeping well and not abusing drugs/alcohol.
2. Since the focus is on student rather than teacher performance, it provides no clear information about ways teachers can improve their practice.
3. Student outcomes may identify teachers who generate a particular test score, but they cannot be used to develop higher levels of effectiveness among all teachers.
The purpose of any effective system should be to improve practice, not simply to measure its outcomes.
LAE supports teacher evaluation systems that are based upon clear standards, encourage professional growth across a teaching career, take account of organizational supports and barriers to effective teaching, empower teachers to examine their work, and are based upon multiple sources of evidence. They should also be linked to teacher professional development.
We push to develop statewide teacher evaluation policies that are evidence-based, supported by research and use multiple measures.
We push to ensure that teachers have an opportunity to provide meaningful input into the evaluation process.
We ensure the evaluation system is designed to improve practice.