Michigan's Great Start Readiness Program (GSRP) is a state-funded pre-K program that serves at risk four-year-old children across the state. Utilizing longitudinal data from 1,394 children in a mid-sized urban school district, we conducted regression analyses and piecewise linear growth models to examine the growth trajectory of GSRP children and…

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,…