A Statistical Perspective on Equating Test Scores
The comparability of scores across different test forms of a standardized assessment has been a major focus of educational measurement and the testing industry for the past 90 years (see Holland, 2007, for a history of linking). This chapter focuses on the statistical methods available for equating test forms from standardized educational assessments that report scores at the individual level (see also Dorans, Moses, & Eignor, Chapter 2 of this volume).
KeywordsItem Response Theory Test Form Test Taker Item Response Theory Model Bifactor Model
Many thanks go to my colleagues Paul Holland, Jim Carlson, Shelby Haberman, Dan Eignor, Dianne Henderson-Montero, and Kim Fryer for their detailed reviews and comments on the material that led to this chapter. Any opinions expressed in this chapter are those of the author and not necessarily of Educational Testing Service.