What Is Value-Added Measurement And How Can We Use It [Or, Even Though VAA Wasn't Designed To Rate Teachers, Let's Use It Anyway!]

Rheelink

Value-added models for assessing student learning and teacher effectiveness are central to a lot of education policy discussions taking place nationally. We have examined the issue in a previous blog post, Fair Incorporation of Student Assessment Data Into Assessments: A Q & A with Dartmouth Professor Douglas Staiger. But questions continually arise on the topic on our StudentsFirst Facebook page. So we thought we'd revisit the subject here.

We know that teacher quality has a significant impact on student learning. We also know that some teachers are more effective than others. In the past, we did not endeavor to identify our most effective teachers nor did schools or districts regularly use teacher effectiveness to make staffing decisions. But in order to best serve students, this has to change. Value-added models, while they should not be used as the sole measure of teacher effectiveness, have an important role to play in teacher evaluation.

Value-added models look at a student's achievement gains, measured by tests taken at the end of the school year, compared to what was expected. Those expectations could be based on previous years' gains, socioeconomic factors and school and class makeup, for example. These models tell us whether students in a teacher's class met, exceeded or fell below expectations. By taking many things into consideration, value-added models can control for many factors that are outside of a teacher's control when it comes to student achievement gains and can more accurately measure the direct impact of the teacher.

Value-added models have their limitations, but they also are an important way of using the data schools are now generating to closely examine what's happening in classrooms across the country. Teachers and school administrators are using value-added models to examine whether students are making the strides expected, to look at learning trends in an entire school or district and to assess the impact teachers are having on student learning. By assessing teacher effectiveness, schools and districts can make better decisions about teacher placement, use the most effective teachers as mentors, ensure that we retain and reward effective teachers, and provide support to those teacher who need it.

We don't think value-added assessments should be the only way to examine teacher effectiveness. Using value-added analysis tells us a lot more than we used to know about teacher performance, but it does not tell us everything -- just as observations in the classroom or looking at a teacher's contribution to the school environment provide an incomplete picture. A quality evaluation system must include multiple components.

We have to continually look at ways to improve our evaluation systems so that they measure teacher effectiveness as accurately as possible. Teachers and students are depending on that. Ultimately, we at StudentsFirst believe that overhauling the way we evaluate teachers and principals is absolutely key to improving student outcomes. Value-added analysis, when used properly, is an important part of the solution and a positive step in the direction of measuring what matters for students.

One of the better reports on value-added analysis was done by the Brookings Institute in November, 2010 and can be found online here: Brookings Report.