December 23, 2003 | By Sam Dillon | New York Times

Public schools with diverse student populations are far more likely than those with homogeneous populations to be labeled as failing under President Bush's education law, known as No Child Left Behind, a California study has found.

The study examined why 3,000 of California's 7,669 public schools were labeled as "needing improvement" under the terms of the federal law, a category that obligates districts to provide transportation for students wishing to transfer to other schools and brings other sanctions in subsequent years.

The study found that many of the 3,000 schools were so labeled not because tests had shown their overall achievement levels to be faltering but because a single student group - for example, disabled learners or Asian students - had fallen short of a target. As a result, the chances that a school would be labeled as failing increased in proportion to the number of demographic groups served by the school, the study found.

"The law penalizes schools that serve more diverse kids," said Bruce Fuller, an education professor at the University of California at Berkeley, who is an author of the study. "Its not that those schools are less effective for average students, it's just that they have all these targets to hit."

The federal law aims to identify educational inequities by requiring schools to disaggregate test scores for every demographic group. If any group fails to meet growth targets, or if its rate of test participation simply falls below the required 95 percent, the entire school misses "adequate yearly progress." If the school misses for two consecutive years, it is labeled as "needing improvement."

The study, which Dr. Fuller wrote with John R. Novak, director of research for the Long Beach Unified School District, identified two Oakland schools whose students, on average, performed at statistically equal levels on standardized tests.

One, Manzanita Elementary, serves a diverse population that includes black, Latino, Asian, low-income and limited-English students. The other, Golden Gate Elementary, serves primarily black students, with some also falling into the low-income category, giving the school just two groups under the federal law's accountability system, the study said.

As a result of its diverse population, Manzanita had to meet test-participation and achievement-growth targets in 18 categories.

Manzanita dramatically raised student proficiency levels, hitting 17 of the 18 necessary targets, the study said. But black students at the school narrowly missed their proficiency target in math. Golden Gate, because of its more homogeneous student body, needed to meet targets in only six categories, and succeeded.

Manzanita was labeled as needing improvement and Golden Gate was not, the study said.

Eugene W. Hickok, the acting deputy secretary of the United States Department of Education, said he was not surprised by the study's results but disagreed with the authors' interpretation.

"There's a certain logic that the more subgroups you have - the more boxes you have to check off - the more difficult it will be to make adequate yearly progress," Dr. Hickok said. "But to conclude that N.C.L.B. punishes diversity is a non sequitur. As a public school, you have an obligation to all your kids. If special ed kids are not doing well, then you have an obligation to take care of that."