The United States is in the midst of an experiment in assessment. In the early 1990s, fewer than 30 states had a statewide assessment system of any kind. Today, every state has at least one—if not five or more—assessment programs, and testing has grown to a $1 billion–$1.3 billion industry (Topol, Olson, & Roeber, 2010). The quest to accurately measure student learning and the things we want kids to know and do well is central to recent U.S. education policy.

The No Child Left Behind (NCLB) Act, the 2001 reauthorization of the Elementary and Secondary Education Act (ESEA), increased the frequency of required state assessments in reading and math from once each in elementary, middle, and high school to annually in grades 3–8 and once in high school. NCLB also added requirements for all students to participate in the statewide assessments, results to be disaggregated by subgroup, science tests to be phased in beginning in 2006, and sanctions for schools with any student subgroup failing to make adequate yearly progress. Moreover, the Individuals with Disabilities Education Acts of 1997 and 2001 reinforced the responsibility of educators to include students with disabilities in statewide assessments.