In this report, Dan Goldhaber of the Center for American Progress analyzes various teacher evaluation processes nationwide and provides recommendations for improving them, since current evaluation systems--to the surprise of no one-- fail to effectively measure the differences in teacher effectiveness. Value Added Measures (VAMs) can replace subjective, binary evaluation methods that have traditionally made teacher performance assessments exercises in futility.
Teachers become undifferentiated widgets under this binary evaluation system, despite evidence that some teachers are more effective than others. Goldhaber suggests that multi-year VAM estimates would decrease the risk of misclassifications by eliminating the statistical noise that can arise from having a strong class one year and a weaker class the next. Using VAMs would provide more transparency to potential classification errors because they are less subjective and can be easily evaluated since they are statistically based. He proposes an evaluation process that uses both observational measures and VAMs to identify low-performing teachers, and suggests that performance evaluations follow teachers from school-to-school and district-to-district.
However, Goldhaber notes the limits of VAMs as well. Most teachers, for example, are in classrooms or grades not covered by state standardized assessments, such as music, art, or first and second grades, making the use of VAMs impossible until state policies are changed. VAMs also fail to measure secondary functions of education, such as socialization behaviors that are taught in the classroom. Finally, VAMs focus heavily on student test scores, and this could result in the role of teachers being reduced to “teaching to the test.”
There is growing demand to reform teacher evaluation systems and value-added data plays an important role. In Ohio, Cincinnati Public Schools renegotiated contracts to establish a more rigorous evaluation process for their teachers. Evaluation methods will now include rigorous reviews by trained evaluators as well as measures of student growth. Statewide policy in Ohio also is headed down this path, as HB 21 which will require the use of value-added data in evaluating teachers (in grades and subjects for which it’s available) and principals for licensure.
"When the
Stakes Are High, Can We Rely on Value- Added? Exploring the Use of Value-Added
Models to Inform Teacher Workforce Decisions"
Center for American Progress
Dan Goldhaber
December 2010