Loudoun County high school seniors posted their best scores ever on this year's SAT, the college entrance exam.

On average, Loudoun's scores rose for the third year, this year by five points to an average of 1059 out of 1600 points, outpacing state and national averages. Students on average scored 533 on the test's verbal section out of a possible 800 and 526 on the math.

"What I'm happy about is that we have a steady increase," said Sharon D. Ackerman, assistant superintendent for instruction. She said incremental rises are preferable to dramatic jumps in some years and large drops in others.

To prepare students for the SAT, the county pays for all students to take the PSAT in ninth, 10th and 11th grades, and Ackerman credited that extra practice, as well as Advanced Placement courses, for the continued rise.

Scores rose at five of Loudoun's seven high schools that had seniors this spring. Dominion High School in Sterling did not have a senior class. The only school to see a dip was Stone Bridge High in Ashburn, where students scored the same as last year on the verbal section of the test but seven points lower in math.

Scores were lowest at Heritage High in Leesburg, which posted an average total of 975. Ackerman noted that this was the first year the school, which opened in 2002, enrolled a senior class, and she said she expected scores to rise with time. She noted, too, that Heritage's first senior class was small, raising the possibility that its average score was affected by just a few low numbers.

Increasingly, Loudoun students appear to be taking the ACT test instead of the SAT, Ackerman said. Both tests are voluntary, and many colleges and universities accept either. Despite the county's rapid growth, only nine more students took the test this year than last, which represented a drop in participation from 78 percent to 72.5 percent of graduating seniors. Ackerman said guidance counselors were also reporting more students choosing to attend Northern Virginia Community College, which does not require an SAT score for admission.

"No one should interpret [the participation rate] as fewer students going on to higher education. That's not the response we got at all from students," she said.

Almost a quarter of students in the county chose not to identify their race when registering for the test, following a trend of the past several years. Of those who did mark their race, scores dropped for both African American and Hispanic students. Ackerman said educators were examining those numbers carefully, especially those for Hispanic students whose average dropped below that of the rest of Virginia. Improvements can best be accomplished by helping to raise the scores of individual students, one by one, she said.