lee collected data across sixty head start classrooms in 2007 and 2008. a sample of 1,260 children ages three to four were selected as the final sample. of these children, 446 had entered head start at age 3 and enrolled for a year (group 1); 498 had been entered at age 4 and enrolled for a year (group 2); and 316 children had been enrolled for 2 years, entering at age 3 (group 3). academic outcome measures in literacy, math and science were collected based on the head start and early childhood program observational checklist rating on a 4-point scale (1—not yet to 4—excels. family risk factor indicators (developed by the state department of education) included single parent, unemployed parent, teenage parent, parental loss (divorce/death), low parental school achievement, food insufficiency. group 3 had higher literacy, math and science scores than the other groups. children in the high-risk group had significantly lower literacy, math, and science scores than those who had three or fewer risk factors. head start is associated with significant gains in test scores. head start significantly reduces the probability that a child will repeat a grade.