HONOLULU — The state Department of Education acknowledged that dropout rates at some Hawai'i high schools are unacceptably high, but a spokesman says figures in a national survey differ sharply with the state's data.

Alaska and Hawai'i are tied for 10th among the states with the highest percentage of "Dropout Factories," according to the survey.

Spokesman Greg Knudsen said the dropout problem is particularly acute at Wai'anae High School, where only 61 percent stick around for their senior year. That's barely outside the category of "Dropout Factory," which researchers define as a school with no more than 60 percent of starting freshmen making it to their senior year.

Researchers for Johns Hopkins University say about 1,700 regular or vocational high schools nationwide fit that description, including seven in Hawai'i, or 17.5 percent of O'ahu's 40 public high schools.

Knudsen points out that in Hawai'i many students move on to private schools, leave because parents are in the military or migrate to the Mainland.

Knudsen also points to a "ninth grade bubble." This year's enrollments in the eighth and 10th grade, for example, both hover around 11,800 statewide, while the ninth grade has 13,950. If 12th grade is compared to ninth grade, the dropout rate would, thus, be inflated, Knudsen says.

The department, by counting each student, says the dropout rate statewide is 15 percent.

The John Hopkins survey showed dropout rates around Hawai'i were 20 to 30 percentage points worse than the state's figures, Knudsen said.

The state data was compiled for reporting under the No Child Left Behind law, he said.

The national study lists Hawai'i's "dropout factories" as Farrington, Kaimuki, Kailua, McKinley, Nanakuli, Wai'anae and Waipahu high schools.