Sources of longitudinal achievement data are increasing thanks partially to the expansion of available interim assessments. These tests are often used to monitor the progress of students, classrooms, and schools within and across school years. Yet, few statistical models equipped to approximate the distinctly seasonal patterns in the data exist,…

School Improvement Grants (SIGs) exemplify a capacity-building investment to spur sustainable changes in America's persistently lowest-performing schools and stimulate the economy. This study examines both short- and longer-term effects of the first two cohorts of SIG schools from four locations across the country. Dynamic…