PORTLAND, Ore. - Just 25 percent of black students in Oregon will graduate from high school, by far the lowest rate in the nation, according to a new survey released Tuesday by an education research group.

The national average graduation rate for black students is 51.6 percent, according to the study by Editorial Projects in Education, the Maryland-based nonprofit organization that publishes the influential newspaper Education Week. The next-lowest state after Oregon was Michigan, where the black student graduation rate is 31.6 percent, according to the report.

Overall, Oregon's graduation rate is 69 percent, according to the group's calculations, about the national average.

That's well below the state's official figure of about 81 percent. The two figures are actually measuring different student groups, said Brian Reeder, an assistant state schools superintendent, though Oregon plans to shift in the future to the survey's method.

Currently, the state measures how many 12th graders who began the school year in September received a regular diploma in June, while the Education Week survey estimated how many 9th graders receive a regular diploma four years later. Both measures exclude students who receive alternative diplomas, like some in the special education population, and those who receive a G.E.D.

A few states, including New Hampshire, South Carolina and Tennessee, were not included in the national group's calculations because of unavailable data.

Reeder said the Education Week numbers on black students seemed particularly high to him. He said state estimates show blacks with a higher dropout rate than whites, but not the kind of disparity to result in the Education Week estimates.

But state Schools Superintendent Susan Castillo said the data still show that Oregon public schools, particularly those in the Portland metro area which educate the bulk of the state's black schoolchildren, have a lot of work to do.

Efforts to steer more students into Head Start programs and full-day kindergarten, and to focus on adult literacy, are aimed at addressing the issue of minority student performance, she said.

"We are doing a lot of things that we believe are going to be turning these numbers around," Castillo said. "It's a matter of us continuing to be very focused, and work in an urgent way on this issue. We don't want to lose a single student in our schools."

Other minority student group graduation figures were also on the low side in Oregon, according to the Education Week study. Just 37.3 percent of American Indian students in Oregon graduate with a regular diploma, compared to 47.4 nationally, the survey found, along with 68.1 percent of the Asian student population, compared with 77 percent nationally.

But at 55 percent, the state's Hispanic students kept pace with their national counterparts.

The Education Week study, funded by the Bill and Melinda Gates Foundation, also shows that Oregon had lagged behind other states in the core requirements students must fulfill in order to receive a diploma before legislators boosted the credits of English required from three to four, and those of math from two to three.

Members of the state Board of Education are now considering upping the science requirement from two years to three, which would outpace the national average of 2.5 required science credits.

Oregon also bucks a national trend by losing the bulk of its students at the 12th grade level, the study shows. Nationally, more than one-third of students leave high school between ninth and tenth grades.

(Copyright 2006 by The Associated Press. All Rights Reserved.)