Evaluators’ Knowledge of Teacher-Level Value-Added Scores Influences Teacher Observation Scores: Evidence of Partial Mediation

• In Event: Roundtable Session 15
  In Roundtable Session: Accountability, Validity, and Teacher Evaluation

Abstract

Teacher evaluation experts are concerned about the validity of value-added models (VAM) as measures of teacher quality, especially when high-stakes decisions are tied to VAM outcomes. Though multi-measure teacher evaluation systems are preferred over single-measure systems to increase fairness and validity, experts are increasingly concerned about purportedly objective measures of teacher quality (i.e., teacher-level value-added scores) influencing subjective measures (i.e., classroom observations), thereby corrupting the validity of the system. Researchers collected data on teachers’ observation and value-added scores and tested a simple mediation model to determine if the relationship between teachers’ observation scores from 2010-2011 and 2011-2012 was mediated by their 2010-2011 value-added scores. Results indicate a partial mediation (i.e., observation scores might have been influenced by previous value-added scores).

Authors

• Jessica Holloway, Kansas State University

• Sarah A. Polasky, Arizona State University