More North Carolina public schools are meeting state test standards, but it's uncertain whether the improvement is due to better teaching or to a change in how schools are evaluated.

Results released this morning show 82 percent of schools met goals this past academic year on the state's ABCs of Public Education program. That is up from 71.9 percent the prior year.

Because of the gain, more teachers whose schools met expectations will be eligible for bonuses. But the state Board of Education cut the size of individual bonuses today by 30 percent because of limited funds.

The improvement coincides with the State Board of Education's decision to exclude new state end-of-grade reading exams in determining which elementary and middle schools receive bonuses. Only math exams counted for bonus purposes this year, though reading exams will count next year.

Other school data released today showed a slight improvement in graduation rates. (An earlier version of this story incorrectly reported that the dropout rate had risen.)

About 70 percent of the state's high school students are graduating in four years, up from 69.5 percent the previous year.

However, today's reports also showed that the percentage of schools meeting standards under the federal No Child Left Behind program has fallen. Only 39 percent of schools met the standards, down from 45 percent the previous year. The percentage probably will drop further this fall when the results of reading tests are factored in.

Both the state and federal programs use many of same tests, but they evaluate the results differently.

The federal program focuses on the percentage of students who pass state reading and math exams at each school. The goal is to close the achievement gap among various groups of students. More schools fell short this year because of an increase in the math passing rates required to meet the federal standards.

The state's ABCs program focuses more on how well students score on exams than on the passing rate for various groups. The state looks at the raw scores and uses a formula to measure school-wide improvement.

If a school's test results meet expectations for improvement, all its teachers can receive bonuses.

Bonuses typically have been as high as $1,500 for teachers and $500 for teacher assistants. But state education officials say they need to reduce the pay-outs because the General Assembly limited spending to $94.3 million for bonuses.

State officials say they would have needed $134.2 million this year to pay full bonuses.

At schools that meet expectations, teachers will get $527 instead of $750. Teacher assistants will get $263 instead of $375.

At schools that exceed expectations, teachers will get $1,053 instead of $1,500. Teacher assistants will get $351 instead of $500.

"These are just tough economic times," said Kevin Howell, a member of the State Board of Education.

Most school districts in the Triangle saw gains in the percentage of schools meeting state expectations. Every school in Orange County and Chapel Hill-Carrboro met state goals.

In Johnston County, 90 percent of schools met expectations, up from 79 percent the previous year.

In Durham, 70 percent of schools met state goals, compared with 50 percent the prior year.

Wake County saw a slight drop with 84 percent of schools meeting state goals, compared with 85 percent previously.

But the results could change in Wake. Knightdale Elementary School's status is under review pending the investigations into allegations of testing irregularities there.

Earlier this week, Knightdale Principal Michael Williams was reassigned to Wakefield High School as an assistant principal. He has been suspended with pay since July 14, although school officials won't say why.

To view the results, go to abcs.ncpublicschools.org.