Unidimensionality and local independence are two common assumptions of item response theory. The former implies that all items measure a common latent trait, while the latter implies that responses are independent, conditional on respondents' location on the latent trait. Yet, few tests are truly unidimensional. Unmodeled dimensions may result in…

For the past decade, the accountability model associated with No Child Left Behind (NCLB) emphasized proficiency on end of year tests; with Every Student Succeeds Act (ESSA) the emphasis on proficiency within statewide testing programs, though now integrated with other measures of student learning, nevertheless remains a primary metric for…

Reading comprehension growth trajectories from 3rd to 7th grade were estimated for 99,919 students on a state reading comprehension assessment. We examined whether differences between students in general education (GE) and groups of students identified as exceptional learners were best characterized as stable, widening, or narrowing. The groups…

Our purpose was to examine different approaches to modeling the time-varying nature of exceptionality classification. Using longitudinal data from one state's mathematics achievement test for 28,829 students in Grades 3 to 8, we describe the reclassification rate within special education and between general and special education, and compare four…

We examined instructional processes in classrooms where students with and without disabilities received mathematics instruction to understand the relationship among key instructional process variables and achievement as measured by interim and end-of-year summative assessments. Teachers (N = 78) completed instructional logs daily and administered…

Students with significant cognitive disabilities are eligible to participate in two statewide testing options for accountability: alternate assessments or general assessments with appropriate accommodations. Participation guidelines are generally quite vague, leading to students "switching" test participation between years. In this…