The Measurement of Student Ability in Modern Assessment Systems

Abstract

Journal of Economic Perspectives—Volume 30, Number 3—Summer 2016—Pages 85–108 The Measurement of Student Ability in Modern Assessment Systems Brian Jacob and Jesse Rothstein E conomists often use test scores to measure a student’s performance or an adult’s human capital. In the research literature on the economics of educa- tion, student test scores are often used to estimate teacher effectiveness, or “­value-added” (for example, Chetty et al. 2014a); to measure and attempt to explain the black–white achievement gap (for example, Fryer and Levitt 2004, 2006, 2013; Rothstein and Wozny 2013); or to measure the impacts of state- or ­district-level educational policy choices such as finance or accountability rules (for example, Dee and Jacob 2011; Lafortune, Rothstein, and Schanzenbach 2016). In the broader labor economics literature, test scores are often used as well as proxies for human capital, for example in examining the black–white wage gap conditional on cogni- tive ability as in Neal and Johnson (1996). In our experience, many researchers think of an individual’s score as a noisy but unbiased measure of true ability like, for example, the simple fraction of test items a student answers correctly. Unfortunately, the student achievement measures provided in modern assessment systems are rarely—if ever—so straightforward. Assessments commonly have multiple forms and are often adaptive, meaning that the questions students receive are based on their performance on previous Brian Jacob is Walter H. Annenberg Professor of Education Policy, Professor of Economics, and Professor of Education at the University of Michigan, Ann Arbor, Michigan. Jesse Roth- stein is Professor of Public Policy and Economics and Director of the Institute for Research on Labor and Employment (IRLE) at the University of California, Berkeley, California. Both authors are Research Associates, National Bureau of Economic Research, Cambridge, Massa- chusetts. Their email addresses are bajacob@umich.edu and rothstein@berkeley.edu. For supplementary materials such as appendices, datasets, and author disclosure statements, see the article page at http://dx.doi.org/10.1257/jep.30.3.85 doi=10.1257/jep.30.3.85