Figure ES.1 Impacts on Reading Achievement, Cohort 2 Follow-Up Respondent Sample
SOURCES: MDRC calculations from the Enhanced Reading Opportunities Study baseline and follow-up GRADE assessments.
NOTES: The baseline GRADE assessment was administered in the fall of 2006 at the start of students’ ninth-grade year and prior to their random assignment to the ERO and non-ERO groups. The follow-up GRADE assessment was administered in the spring of 2007 near the end of students’ ninth-grade year.
The ERO group growth at follow-up is calculated as the difference between the unadjusted ERO group mean at baseline and the unadjusted ERO group mean at follow-up. The impact was estimated using ordinary least squares and adjusted to account for the blocking of random assignment by school and to control for random differences between the ERO and non-ERO groups in baseline reading comprehension test scores and age at random assignment. The expected ERO group growth at follow-up is the difference between the actual ERO group growth and the impact.
A two-tailed t-test was applied to the impact estimate. The statistical significance is indicated (*) when the p-value is less than or equal to 5 percent.
The national average for standard score values is 100, and its standard deviation is 15.
Rounding may cause slight discrepancies in calculating sums and differences.