This exploratory study investigated potential sources of setting accommodation resulting in differential item functioning (DIF) on math and reading assessments for examinees with varied learning characteristics. The examinees were those who participated in large-scale assessments and were tested in either standardized or accommodated testing…

Background: Cluster-randomized experiments that assign intact groups such as schools or school districts to treatment conditions are increasingly common in educational research. Such experiments are inherently multilevel designs whose sensitivity (statistical power and precision of estimates) depends on the variance decomposition across levels.…