Abstract
Despite focused efforts, achievement gaps remain a problem in the America's education system, especially those between students from higher and lower income families. Continued work on reducing these gaps benefits from an understanding of students' reading and math growth from typical school instruction and how growth differs based on initial proficiency, grade, and demographic characteristics. Data from 5,900 students in Grades 1-5 tested in math and reading at six points across two years were analyzed using cohort-sequential latent growth curve models to determine longitudinal growth patterns. Results indicated that students with low initial proficiency grew more quickly than students with higher proficiency. However, after two school years their achievement remained below average and well below that of students with higher initial proficiency. Demographic characteristics had small but significant effects on initial score and growth rates.