Reading scores among fourth- and eighth-graders showed little improvement over the past two years, and math gains were slower than in previous years, according to a study released yesterday. The disappointing results came despite a new educational testing law championed by the Bush administration as a way to improve the nation's schools.

Most troubling for educators are the sluggish reading skills among middle-school students, which have remained virtually unchanged for 15 years, according to the National Assessment of Educational Progress, which administers the federal test and bills itself as the "nation's report card."

Though the tests have been taken by fourth- and eighth-grade students about every two years since 1990, the latest NAEP scores were the first tangible testing numbers available since the implementation of No Child Left Behind -- the Bush administration's premier and controversial education initiative requiring all states to test students annually as a prerequisite for receiving federal funds.

"No one can be satisfied with these results," said Ross Wiener, policy director for the Education Trust, an advocacy organization that backed No Child. "There's been a discernible slowdown in progress since '03, at a time when we desperately need to accelerate gains. The absence of particularly bad news isn't the same as good news."

The administration today scrambled to put the best face on the numbers and to defend the law that some complain forces a test-driven curriculum on the classroom. The White House hastily arranged media availability with President Bush and Education Secretary Margaret Spellings. Bush called the report "encouraging" and emphasized that the numbers showed a narrowing of the achievement gap between white and minority students. "And that's positive, and that's important," the president said.

Spellings initiated a conference call with reporters and reached out to individual news organizations. She, too, said she was encouraged by the tightening of the achievement gap, a trend that began in 2000.

But Wiener of the Education Trust said: "It is meager progress. Students of color and low-income students continue to be educated at levels far below their affluent peers."

Spellings also pointed out that the 2002 No Child law is still not fully implemented, and that the state-by-state results will help policymakers pinpoint deficiencies in their schools.

Scores in the District were well below the national average, with students ranking at the bottom in all testing categories. Still, there was evidence of progress. The number of District fourth-graders who scored below basic level in math decreased from 64 percent in 2003 to 55 percent this year. The number of eighth-graders who scored below basic in math dropped from 71 to 69 percent. And the number of fourth-graders who scored below basic in reading fell from 69 to 67 percent.

But mirroring national reading trends, the number of eighth-graders scoring below basic increased from 53 to 55 percent.

Maryland's performance was flat in most areas, but education officials noted it was the first time the state had matched or exceeded the national average in both subjects and grade levels tested. The percentage of Maryland students judged proficient on the national test ranged from a low of 30, in both eighth-grade reading and math, to a high of 38 percent, in fourth-grade math. Proficiency rates run far higher on the Maryland School Assessment, the statewide test required by the No Child Left Behind mandate.

In Virginia, fourth-graders made slight gains in both math and reading and average scores in the state exceeded the national average. Thirty-seven percent of fourth-graders earned a "proficient" score in reading, up two points from 2003, and 39 percent of children are considered proficient in math, compared with 35 percent in 2003.

Virginia's eighth-graders also showed modest improvement in math, with 33 percent performing well enough to be considered proficient, up from 31 percent. The percentage of eighth-graders earning proficient reading scores remained constant at 35 percent.

"While much remains to be done to strengthen the reading and mathematics skills of our students, the incremental increases in achievement we are seeing . . . show that our schools are moving in the right direction," Virginia Superintendent of Public Instruction Jo Lynne DeMary said in a statement.

Some scholars cautioned against tying the scores directly to No Child this early. "Let's put it this way," said Tom Loveless, a senior fellow at the Brookings Institution, "reading scores were flat and math scores on the rise before No Child Left Behind, and reading scores are flat and math scores are still up after No Child Left Behind. It's impossible to know whether NCLB had an impact -- either positively or negatively."

Loveless and others point to the nation's changing school demographics, which show a doubling of the number of Hispanic students in the last 15 years, some of whom may be struggling with the English language. "These students create enormous labor costs to the schools because they need additional attention," said Darvin Winick, chairman of the National Assessment Governing Board, which oversees NAEP testing.

The strongest results nationally were in math, but growth was slower over the past two years than it had been over the previous three. Scores were up in fourth grade for white, black and Hispanic students; math scores also increased in eighth grade. The numbers indicated that 36 percent of the nation's fourth-graders and 30 percent of eighth-graders reached a level of proficiency -- the level at which the administration strives to have every child by 2013.

In fourth grade, the average reading score rose one percentage point and stayed flat in measures of proficiency. Reading scores among eighth-graders went down a point since 2003, as did the number of proficient readers in that grade.

Staff writers V. Dion Haynes, Daniel de Vise and Maria Glod contributed to this report.