The change involves the No Child Left Behind Act, which currently allows states to use their own methods of calculating graduation rates and set their own goals for improving them. The report by the America's Promise Alliance, using a common method to evaluate graduation rates for cities, found the lowest graduation rates in Detroit, Indianapolis and Cleveland.
It found that about half of the students served by public school systems in the nation's largest cities receive diplomas; students in suburban and rural public high schools were more likely to graduate than their counterparts in urban public high schools.
Nationally, about 70 percent of U.S. students graduate on time with a regular diploma and about 1.2 million students drop out annually.
"When more than 1 million students a year drop out of high school, it's more than a problem, it's a catastrophe," said former Secretary of State Colin Powell, founding chair of the alliance.
The group announced plans to hold summits in every state during the next two years on ways to better prepare students for college and the work force.
The report found troubling data on the prospects of urban public high school students getting to college. In Detroit's public schools, only 24.9 percent of the students graduated from high school, while 30.5 percent graduated in Indianapolis Public Schools and 34.1 percent received diplomas in the Cleveland Municipal City School District.
Researchers analyzed school district data from 2003-2004 collected by the U.S. Department of Education. [ See the graduation rates for the nation's 50 largest cities ] To calculate graduation rates, the report estimated the likelihood that a 9th grader would complete high school on time with a regular diploma. Researchers used school enrollment and diploma data, but did not use data on dropouts as part of its calculation.
Many metropolitan areas also showed a considerable gap in the graduation rates between their inner-city schools and the surrounding suburbs. Researchers found, for example, that 81.5 percent of the public school students in Baltimore's suburbs graduate, compared with 34.6 percent in the city schools.
In Ohio, nearly 83 percent of public high school students in suburban Columbus graduate while 78.1 percent in suburban Cleveland earn their diplomas, well above their local city schools.
Ohio Department of Education spokesman Scott Blake said the state delays its estimates by a few months so it can include summer graduates in its calculations. Based on the state's methodology, he said, Columbus graduated 60.6 percent of its students in 2003-2004, rather than the 40.9 percent the study calculated.
By Ohio's reckoning, Columbus has improved each year since the 2001-2002 school year, with 72.9 percent of students graduating in 2005-2006, Columbus Public Schools spokesman Jeff Warner said.
Warner said the gains were partly because of after-school and weekend tutoring, coordinated literacy programs in the district's elementary schools and a strengthened program involving English-as-a-second-language.
Cleveland's current graduation rates are also higher than the statistics cited in the new report, school district spokesman Ben Holbert said.
Spellings and others have previously said a revised No Child Left Behind law should make states provide graduation data in a more uniform way. However, efforts to rewrite the law on Capitol Hill have stalled.
Under the 2002 law, schools that miss progress goals face increasing sanctions, including forced use of federal money for private tutoring, easing student transfers, and restructuring of school staff.
The research behind the report out Tuesday was conducted by Editorial Projects in Education, a Bethesda, Md., nonprofit organization, with support from America's Promise Alliance and the Bill & Melinda Gates Foundation.
The alliance is based on a joint effort of nonprofit groups, corporations, community leaders, charities, faith-based organizations and individuals to improve children's lives.