Teacher Evaluation

Using Test Results to Evaluate Teaching

Good teaching is critical to student learning, and ETS is well-versed in states' needs related to educator assessment and certification, teaching standards, professional development and the evaluation of teacher quality.

In this last area, specifically, federal and state policymakers have mandated the use of student achievement results as part of educator evaluation systems. Many school systems are working with measurement experts and research scientists to explore the potential and limitations of value-added models (VAMs) for this purpose. The simple logic behind the interest in VAMs is that if good teaching is critical to student achievement, wouldn't it make sense to use evidence of student learning to determine a teacher's contributions?

VAMs, which are based on complex statistical methods, attempt to estimate a teacher's contributions to student learning by making use of test score data that tracks each student's academic growth. However, there are many issues that should be considered before incorporating the method. One is that VAM estimates can be unstable year to year, attributable in many cases to the small number of data points available in any one year. In addition, VAM approaches were not designed to accommodate team teaching situations or children who move out of or move into the school during the school year.

Systems should use multiple measures in educator evaluation systems, incorporating VAM estimates alongside classroom observation ratings and other measures of effectiveness. For states considering VAMs, ETS can help assist and guide them as they address the valid use of student performance on the consortium tests during the design phase.

Several reports on teacher effectiveness, authored or co-authored by Laura Goe, senior research scientist in the Teaching Quality Research Center at ETS and Principal Investigator for Research and Dissemination for The National Comprehensive Center for Teacher Quality, delve deeper into the subject:

• Measuring Teachers' Contributions to Student Learning Growth for Nontested Grades and Subjects aims to help states consider options for assessing student learning growth for the majority of teachers who teach content not assessed through standardized tests.
• A Practical Guide to Evaluating Teacher Effectiveness outlines the methods available to measure teacher effectiveness and discusses the utility of these methods for addressing specific aspects of teaching.
• Approaches to Evaluating Teacher Effectiveness: A Research Synthesis examines how teacher effectiveness is currently measured.