Principles and Practices of Test Score Equating. Research Report. ETS RR-10-29

Score equating is essential for any testing program that continually produces new editions of a test and for which the expectation is that scores from these editions have the same meaning over time. Particularly in testing programs that help make high-stakes decisions, it is extremely important that test equating be done carefully and accurately. An error in the equating function or score conversion can affect the scores for all examinees, which is both a fairness and a validity concern. Because the reported score is so visible, the credibility of a testing organization hinges on activities associated with producing, equating, and reporting scores. This paper addresses the practical implications of score equating by describing aspects of equating and best practices associated with the equating process. (Contains 4 tables and 4 notes.)