Students in Fairfax and Loudoun counties did better on state achievement tests this year and about three times as many Fairfax schools reached the state's target for performance on the exams, according to figures released yesterday.

Fairfax School Superintendent Daniel A. Domenech hailed the improvement but predicted smaller gains in future years. He repeated his call for changes in the state history tests, saying that they emphasize knowledge of facts rather than an understanding of concepts.

The percentage of Fairfax students passing the Standards of Learning (SOL) tests increased for all of the 27 exams but one, the high school earth science test, according to the figures Domenech announced yesterday. The figures are based on the county's calculations and could change slightly when the state releases the official results for local districts next month.

The tests, which were administered for the first time in 1998, are given in grades 3, 5 and 8 and in high school. Fairfax's passing rates this year ranged from 91 percent on the fifth-grade technology test to 47 percent in high school U.S. history. The county's passing rates were higher than the statewide average on every test except high school chemistry.

Loudoun students showed improvement on the exams and exceeded the state average on each of the tests. Gains also were reported earlier in Arlington, Alexandria and Prince William.

The number of Fairfax schools meeting state standards rose from 13 to 40, Fairfax officials said, while Loudoun officials said they have not calculated their figure. A school must have a passing rate of 70 percent on each SOL test to reach the state benchmark, except for third-grade science and history, where a passing rate of 50 percent is enough. Any school that fails to reach the target by 2007 will lose its accreditation.

Despite the sharp jump in the number of Fairfax schools making the grade, Domenech said he still believes that unless the standards are changed, only 60 to 70 percent of the county's 202 schools will have reached the state target by 2007, a prediction he first made after the 1998 scores were released.

Less than 3 percent of schools statewide met the accreditation standards in 1998. State officials have yet to calculate how many schools are in that category this year.

At the news conference he held yesterday to announce the Fairfax scores, Domenech was critical of the history tests, where county students had their lowest scores. Twenty-four additional Fairfax schools would have reached the state targets if not for their performance in history.

State officials say the history scores will improve once teachers become accustomed to the state's new curriculum guidelines, but Domenech questioned whether those guidelines are appropriate.

"It will narrow our focus and narrow our curriculum," Domenech said of the state's approach to teaching history. "It will narrow our enrichment opportunities."

Oakton Elementary School had passing rates of 88 percent in third-grade English and 96 percent in fifth-grade writing, but failed to make the state target because of a 56 percent passing rate in fifth-grade history. "I think our test scores will go up because we will become test-wise," said Oakton Principal Juanita Trotter, "but I am not sure we want that for our children."

Fairfax School Board member Stuart D. Gibson (Hunter Mill) said he had heard such complaints but preferred to emphasize the positive. "We are certainly going in the right direction," he said. "Now is when we need to do even more."

Most of the 40 Fairfax schools that met the state requirements were in relatively affluent areas of the county. Fifteen have special programs that draw students designated as gifted from outside the school neighborhood.

Domenech said he was disturbed by the county's 58 percent passing rate in high school chemistry, below the 64 percent state average. He said he called his chemistry coordinator for an explanation and was told that because Fairfax puts many of its high school students on a fast academic track, most of its chemistry students are 10th-graders, while elsewhere in the state they are 11th-graders.

He said school officials would look into whether some of the Fairfax 10th-graders taking chemistry do not have enough of a math background.

MAKING THE GRADE

These Northern Virginia schools met the state's benchmarks for performance on the Standards of Learning tests taken last spring, according to unofficial results compiled by local school officials.

Arlington elementary schools:

* Arlington Traditional

* Jamestown

* Key

Fairfax elementary schools:

* Belvedere

* Canterbury Woods

* Chesterbrook

* Churchill Road

* Crossfield Corner

* Fairfax Villa

* Fairhill

* Forest Edge

* Forestville

* Franklin Sherman

* Great Falls

* Greenbriar West

* Haycock

* Hunt Valley

* Keene Mill

* Kent Gardens

* Kings Park

* Laurel Ridge

* Little Run

* Mantua

* North Springfield

* Oak Hill

* Orange Hunt

* Sangster

* Spring Hill

* Springfield Estates

* Union Mill

* Wakefield Forest

* West Springfield

* Willow Springs

* Wolftrap

Fairfax middle schools:

* Cooper

* Franklin

* Frost

* Holmes

* Lake Braddock

* Longfellow

* Carson

* Thoreau

Fairfax high schools:

* Thomas Jefferson

NOTE: Loudoun and Fauquier counties have yet to determine whether any of their schools met the standards.