A year ago, Dodge Park Elementary in Landover was nobody's poster school. Three quarters of its third- and fifth-graders failed to show proficiency on state reading and mathematics tests. Stagnant scores landed the school on a state watch list.

Yesterday, Prince George's County school and elected officials converged on the modest hilltop campus to give its rookie principal, Judith White, a standing ovation for a breakthrough. More than half of Dodge Park's students reached proficiency in reading and math, according to Maryland School Assessment test data made public this week.

In practical terms, that means a student's grade level within the school now stands for something other than mere age.

"Reform doesn't happen unless it happens at the schoolhouse level," said Leroy Tompkins, the school system's chief accountability officer, as he highlighted Dodge Park and other testing bright spots in a news conference that had the air of a pep rally.

Rising scores at Dodge Park, a high-poverty school with predominantly black students, fit a larger pattern in which the county's test results rose overall at a faster clip than the state average, helping to narrow a stubborn black-white achievement gap statewide and buff, a bit, the image of a suburban Washington school system that has long had a lackluster reputation.

The developments were a welcome change of topic for officials who have had to respond to the May 27 resignation of schools chief Andre J. Hornsby amid an FBI investigation and ethics controversy.

"This news today will elevate us, perception-wise and in reality," said County Executive Jack B. Johnson (D). "We're on the right track."

With school test scores, achievement is always relative. All school systems face pressure under the federal No Child Left Behind law to raise minority student performance. Montgomery County's black and Hispanic students made major strides this year. So did black students in Anne Arundel County.

Caveats abound for the Prince George's scores. The 2005 tests, taken in March in elementary and middle schools, still show the system near the bottom of the pack, far trailing others in the percentage of students reaching advanced performance. Of 24 systems statewide, data seem to show that only Baltimore city schools scored lower than Prince George's overall.

Dorchester County schools, on the lower Eastern Shore, ranked behind Prince George's in eighth-grade math and third-grade reading. So did Somerset County schools, also on the Eastern Shore, in fifth-grade reading.

When compared with its Maryland neighbors, Prince George's still scores lower, well behind Howard, Calvert, Anne Arundel and Montgomery counties and somewhat behind Charles County.

In addition, Prince George's has more schools on the state watch list -- 73 -- than any system except Baltimore City. When the state releases new ratings in coming days that show how many schools made adequate yearly progress according to federal law, Prince George's might have to do more explaining than boasting. A school could be considered failing if just one group, such as special education students, do not show sufficient improvement. Dodge Park, for instance, is thought to be just on the cusp of making adequate progress.

Only four county schools of the 73 rated as needing improvement are eligible for removal from the watch list, Tompkins said, because the law requires adequate progress two years in a row.

Still, analysis of the state test data by The Washington Post shows that Prince George's shrank some achievement gaps from 2003 to 2005.

* In third-grade math, the percentage of students reaching proficiency or better climbed 16 points in Prince George's, to 65 percent from 49 percent. That was a faster rate of growth than in most other systems. The state average climbed 12 points.

* In third-grade reading, the Prince George's proficiency-or-better percentage rose 24 points. The state average climbed 18.

* In fifth-grade reading and math, the Prince George's proficiency-or-better percentage scores rose 13 and 15 points, respectively, while the state averages climbed 9 points for reading and 14 points for math. And in the same comparison for eighth-grade reading and math, Prince George's kept pace with or gained on the state.

These findings are significant because the county has more public school students (136,000, as of September) than any county in Maryland except Montgomery (139,000). It also has more black students -- 105,000 -- than any county, and the second-largest population of Hispanic students (17,000, after Montgomery's 27,000).

Officials heaped credit on Prince George's teachers and principals. Tompkins cited the new textbooks, a more focused county curriculum, a strategic plan, teacher and staff training, vacation homework packets and extra test preparation.

Unmentioned was the leader who had preached those initiatives for two years and appointed principals such as Judith White. Hornsby e-mailed a statement to The Post: "When you surround yourself with talented people and provide school leaders and teachers with the instructional resources and professional development clearly focused on teaching and learning, the results speak for themselves."

Test results for individual schools can be found at www.mdreportcard.org. Click on the name of a county and then the link labeled, "How did our schools perform?"