"Pump it up, pump it up! Keep it going, keep it going!"

With cheers and clapping, the children who were crowded into the worn cafeteria of Plummer Elementary School in Southeast Washington chanted their mantra.

"Let's lead, let's learn, let's go. You know!"

Three times a week, the "scholars" of Higher Achievement -- a private academic enrichment program for disadvantaged fifth- through eighth-graders in the District -- gather to celebrate their not-inconsiderable achievements.

At Plummer, one child after another pops up to "shout out" his or her academic accomplishments.

"I'd like to give myself a shout-out for getting an A on my math and an A on my Spanish exams," said Dominique Tucker, 12.

"I got a 37 out of 40 on my math test," a child called out.

"I would like to give my shout-out for finally finishing 'Siddhartha' after two weeks," yelled another little girl.

This academic cheerleading is an integral part of Higher Achievement, a 30-year-old after-school program that survived a near-death experience in the late 1990s and came roaring back. It has 300 students in four centers, which are housed in D.C. public school buildings.

Its focus on rigorous academics is gaining the program national attention. It has won several national and local awards recently, including the Bank of America Neighborhood Builders award for its work to improve communities and the NPower/Accenture award for its innovative technology. A national research program is studying it to gauge the effect of such programs on middle schoolers' academic achievement. And earlier this year, President Bush dropped by to honor Higher Achievement and other programs that serve youths.

"One of the interesting things about the Higher Achievement program, they have got a good track record, good results," he said during his visit in April to the Paul Public Charter School in Northwest. "If you're interested in finding out what works, look at this program, because the results are clear."

Higher Achievement is launching an ambitious expansion into Alexandria next summer and then into Prince George's County. Within five years, it plans to triple in size.

Its goal is to immerse promising low-income students in a rigorous academic program to ready them for a challenging high school curriculum and educational paths beyond.

New research on middle schoolers supports programs such as Higher Achievement, said Michael Petrilli, a vice president at the Thomas B. Fordham Foundation, an organization that studies education.

Many school systems have dumbed down their middle school curriculum because of research that purported to show that brain development slows in children in that age group, leaving them less able to learn, Petrilli said.

That research proved to be "nothing but bunk," he said.

"The idea that early adolescence is a time when you just can't push students to learn very much . . . just isn't true," he said.

Academic rigor is the soul of Higher Achievement, its leaders say. Children spend 650 hours per school year in the free program, in addition to 900 hours in school. Students who apply to the program are interviewed and chosen on the basis of their potential and hunger to learn. About half of those admitted are C and D students.

"Intellectual capacity is built through effort," said Maureen Holla, the program's executive director. "Hard work builds intellect. The harder you work, the smarter you get."

During the school year, the children meet three days a week from 3:30 to 8 p.m. for homework help, instruction in math, literature, science and other subjects, and mentoring time with volunteers. During the summer, the program runs from 8 a.m. to 4 p.m. five days a week.

The intent, Holla said, is to "flood" children with academic opportunities.

"We are very rigorous and very deep," said Carlos Garcia, chairman of Higher Achievement's board of directors, who has been involved with the organization since the 1990s.

"This is a critical intervention in a child's life, and time on task really matters," he said. "You have to really, really envelope them in this environment."

Just over half of all Higher Achievement scholars, as they're called, increased their standardized reading scores in recent years after joining the program, and 62 percent boosted their math scores.

Seventy-five percent go on to challenging public and private high schools, such as St. Albans, National Cathedral, Benjamin Banneker Academic and the School Without Walls, and 95 percent of the children who complete Higher Achievement's four years go onto college. Higher Achievement kids have graduated from Harvard, Stanford, Yale, Howard and Brown, among dozens of other schools.

At Higher Achievement's center at Stuart-Hobson Middle School on Capitol Hill, teacher Rudy McCann of the Capitol Hill Arts Workshop dragooned her trio of students into a discussion of a poem titled "Kaleidoscope," by Philadelphia poet Sonia Sanchez. The boys reacted with typical teenage apathy, but, with only three in the class, there was no room to hide from their teacher's prodding.

"I don't think it's very good because it's slow and it's boring," said Driscoll Warner, 12.

"What does boring mean?" McCann asked.

"The first two lines don't make me want to read it," he said.

"Okay," McCann said. "That's a very good way to express yourself."

They searched for the verbs in the poem, and Driscoll corrected Chris Jackson when he mistakenly labeled an adverb as a verb.

In interviews, several children said they didn't mind that their studies keep going after the school day ends.

"The program is superb," said Aaron Garvin, a solemn-faced 11-year-old who attends the Ward 7 Higher Achievement center at Plummer Elementary. "Sometimes, I'm going to admit, when my mother brings me, I fuss and fight. And then when I get here, all those troubles are gone."

Like some of the children in the program, Higher Achievement has been through hard times.

Launched by Jesuit teachers at Gonzaga College High School in Northwest Washington in 1975 to help bright inner-city middle school kids get more prepared for Gonzaga's rigorous academics, the program had expanded to nine centers over two decades.

But with lackluster fundraising, falling enrollment and parents who were unhappy with the program's limited hours, the volunteer board of directors laid off the staff and shut down Higher Achievement in early 1998.

Then the leaders regrouped and hired Holla. The program reopened six months later with just 30 students, but with expanded services. The number of hours available to the children was quadrupled, and they were offered homework help on top of Higher Achievement's curriculum.

Nkechi Feaster, 30, whose 12-year-old son Chris joined Higher Achievement last spring, is pleased with his progress.

"When I found the program, I thought it would be great, because on a regular basis he would be with kids who were along his level of intelligence. He has some place to go with kids that are more like him," said Feaster, formerly a homeless single mom who now works as a clerk at a Georgetown law firm. "When he's with [Higher Achievement], I don't worry about him. And there aren't too many places like that."

For more information, call 202-544-3633 or visit higherachievement.org.

Fifth-grader Daria Fogan awaits her turn during "shout-outs" at a Higher Achievement center in Northeast.Daria Fogan reads aloud to her group, including sixth-grader Johniece Sheppard, left. The program has 300 students.Seventh-graders Demario Ford, right, Marquise Cotten, left, and Driscoll Warner, kneeling, work a problem with volunteer Lisa Tran at the Higher Achievement center at Fourth and E streets NE. President Bush praised Higher Achievement's "good results" during a visit in April to the Paul Public Charter School, which houses one of the program's four centers. At left, Adrian Wright helps Daria Fogan and sixth-grader Daron Brown at the Stuart-Hobson center in Northeast.