Value-Added to What? How a Ceiling in the Testing Instrument Influences Value-Added Estimation
42 Pages Posted: 31 Aug 2008 Last revised: 13 Mar 2009
Date Written: February 20, 2009
Value-added measures of teacher quality may be sensitive to the quantitative properties of the student tests upon which they are based. This paper focuses on the sensitivity of value-added to test-score-ceiling effects. Test-score ceilings are increasingly common in testing instruments across the country as education policy continues to emphasize proficiency-based reform. Encouragingly, we show that over a wide range of test-score-ceiling severity, teachers' value-added estimates are only negligibly influenced by ceiling effects. However, as ceiling conditions approach those found in minimum-competency testing environments, value-added results are significantly altered. We suggest a simple statistical check for ceiling effects.
Keywords: value added, test-score ceiling, ceiling effects, teacher performance
JEL Classification: I20, I21
Suggested Citation: Suggested Citation