Two new studies shed light on how the achievement gaps between groups of students grow as they move from elementary to middle school.
The studies鈥攐ne by researchers Eric A. Hanushek and Steven G. Rivkin and the other by the Northwest Evaluation Association鈥攂oth found that black students start out school trailing behind their white counterparts, learn less over the course of the school year, and fall further behind as they progress through school.
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But the studies diverge as they try to pinpoint potential causes for those learning gaps.
Mr. Hanushek and Mr. Rivkin, both university-based economists, suggest that the growth in the size of the learning gaps that occur as children move from kindergarten through 8th grade can be explained by certain differences in the schools that black and white children attend.
Catch-Up Unlikely
By and large, the study found, African-American children are likely to attend schools that are more racially isolated, have more inexperienced teachers, and have higher rates of student mobility than the schools that white children attend鈥攁nd most of those factors pose bigger learning impediments for black children than for white students. 鈥淭he dilemma of this paper is that we find school factors are very important, but it鈥檚 very hard for schools to change those specific factors,鈥� said Mr. Hanushek, a senior fellow at the Hoover Institution, a think tank based at Stanford University.
The analysis by the Northwest Evaluation Association, by comparison, found that African-American, Hispanic, and poor students also tend to lose much academic ground over the summer when they are out of school. 鈥淲hich makes me think it鈥檚 probably not completely a school factor,鈥� G. Gage Kingsbury, the chief research and development officer for the association, said in seeking to explain the gaps in achievement.
Researchers at the NWEA, a nonprofit organization in Portland, Ore., that provides testing services in 24 states, analyzed achievement data from grades 3-8 for 570,00 students in reading and 540,000 students in math for the report. The report was slated for release this week.
Mr. Kingsbury said the gaps the authors found between black and white students, Hispanic and white non-Hispanic students, and poor and better-off students start out small but could grow up to 10 times larger by the time students leave school.
鈥淟et鈥檚 say two students start out as average 3rd graders,鈥� Mr. Kingsbury said. 鈥淚f their differences grew to a standard deviation, that would mean the high-poverty student would be seen as borderline special education, and the student in low-poverty schools would be average.鈥�
Part of the problem, the researchers found, was that poor and minority students learned less over the course of the school year than their white or wealthier counterparts who started out the year at the same achievement levels. In addition, though, the poor and minority students lost more academic ground over the summer.
With such learning-growth patterns, Mr. Kingsbury said, poor and minority children are unlikely to catch up to their higher-achieving peers any time soon.
Mr. Kingsbury said that doesn鈥檛 necessarily mean, though, that schools will be unable to meet the targets set out for them under the federal No Child Left Behind Act for improving the test scores of student subgroups, such as racial and ethnic minorities. 鈥淛ust being proficient doesn鈥檛 mean you鈥檙e even with everybody else who鈥檚 proficient,鈥� he observed.
Racial Makeup Key
For their study, Mr. Hanushek and Mr. Rivkin analyzed assessment results from two databases and focused just on the academic differences between African-American and white students.
One database was the Texas Schools Project at the University of Texas at Dallas, which contains longitudinal achievement data on all students enrolled in that state鈥檚 public elementary schools from 1990 to 2002. The researchers looked in particular at data for more than 800,000 students in grades 3-8.
For data on younger students, the authors drew on a federal study that is tracking a nationally representative sample of students beginning in kindergarten. The researchers posted their results last week on the Web site of the National Bureau of Economic Research, a nonprofit group based in Cambridge, Mass.
The researchers said they focused on the share of black students within schools, the numbers of beginning teachers on staff, and student turnover. They chose those factors because previous studies have suggested that they affect African-American students disproportionately.
Of the three, the most critical school characteristic for black students seemed to be their schools鈥� racial composition. According to the report, the more concentrated that black students are in a school, the more rapid the growth in achievement gaps between black and white students. The negative impact of attending a racially isolated school, the study also found, tends to be greatest for black students who start out at the high end of the achievement spectrum.
鈥淭he positive aspect of all this is that schools matter,鈥� said Mr. Rivkin, an economics professor at Amherst College in Amherst, Mass., and the associate director of research for the Texas Schools Project. 鈥淚t鈥檚 not that these things are preordained or based upon what kind of early-childhood experiences people have.鈥�
