There has been much discussion about the gaps in childhood educational achievement in North Carolina: gaps between previous and current test scores and gaps in black and white achievement.
But the most important gap is eluding public discussion. The major determinant of success on end-of-grade testing, and of supposed school quality is, unequivocally, the economic status of the students. This is readily apparent from a statistical analysis of the correlation between the percentage of children attaining grade appropriate scores (pass rate) and the percentage of children eligible for free or reduced lunches.
An analysis of data for schools in the Raleigh-Durham-Chapel Hill region, published Nov. 8 in The News & Observer, shows an extraordinarily powerful relationship between free and reduced lunch status and the test pass rate. Schools with high percentages of poor children have low pass rates. Schools with low numbers of poor children have high pass rates. It is that simple.
In medical research we measure the correlation, or inverse correlation, between two factors by a statistical test called linear regression. The R2 is the strength of association between two or more variables; the higher the value, the stronger the link. As an example, the R2 value is a measure of value correlating total alcohol consumption and death from cirrhosis approximates 0.4-0.5. This indicates a strong correlation between high alcohol consumption and cirrhosis mortality.
The R2 value correlating test passage rate and percentage of students on the subsidized lunch program is far higher; it approximates 0.85. This very high value signifies that 85 percent of variability in school performance is explained by the economic well-being of a childs family, as measured by eligibility for subsidized lunches. This in turn suggests that poverty encompasses, and/or is associated strongly with, most factors that determine test performance during the elementary and middle school years. For one factor to have such a powerful impact on educational outcome is revealing and must be addressed.
Several conclusions are justified:
• First, the dominant factor explaining major gaps in school performance are neither race nor locale, but economic class.
• Second, high performing schools, despite what many believe, are usually schools with very few poor children.
• Third, this extraordinarily tight inverse correlation between class and test scores is well established by the time children enter elementary school and does not appear to change significantly with time.
It should be noted that no data indicate that children attending low-performing schools are doomed to poor outcomes. Our own children and their friends have succeeded both academically and professionally despite attending low-performing schools. Rather, the data demonstrate that poverty and its ramifications plague our communities and limit prospects for a large number of our communitys children.
Responses to recent school testing results suggesting that an increase in school funding will not impact the achievement gap are simplistic and fail to address the fundamental problems underlying educational failure.
Pediatricians are familiar with developmental research demonstrating that fundamentals of language, reading comprehension and reasoning are established by the age of 3. This fact, coupled with the well-established inverse correlation between school performance and economic class, suggest that gaps in educational achievement must be addressed through very early childhood intervention, particularly for those at high risk of school failure. The gap in test scores requires allocation of more, not less, resources for education. Some of these resources should be targeted to enhancing educational opportunities for young children of low-income families.
Funding alone will not resolve all of our problems, but it will help. More educational opportunity at an earlier age will enhance the likelihood that testing gaps can be narrowed. And, with the narrowing of gaps in educational attainment, children of poverty will have a better opportunity to escape that poverty as adults.
Dr. Michael Freemark is a Professor of Pediatrics at Duke University Medical Center. Anne Slifkin is an attorney based in Raleigh.