A decade ago, Mount Vernon High School installed the International Baccalaureate program -- an obscure and difficult curriculum created in Switzerland -- because it needed something to save its plummeting academic reputation.

The sprawling campus of 1,700 students near Fairfax County's Route 1 corridor was absorbing a flood of low-income black and Hispanic students with low test scores, and middle-class families of all races were moving out. "No one wanted to go to that school if they didn't have to," said Robert R. Spillane, who was county school superintendent at the time.

By the end of the first year, the average score for the new IB students was below 4 (on a 7-point scale), the minimum for college credit. IB coordinator Betsy Calhoon, a slender, soft-voiced woman with fading red hair, wondered how the school would handle such a challenge.

And yet a decade later, the average IB test score at Mount Vernon has climbed to 4.51, a significant jump on the short scale. Nearly 400 students -- almost half of the school's juniors and seniors -- are taking the courses. And 35 percent of the IB students are black or Hispanic, a rare achievement for college-level programs, which usually have few minorities.

The once-unknown program has spread to two dozen other Washington area public high schools, including new IB schools this year in Montgomery and Anne Arundel counties, and has begun to inspire pre-IB programs in elementary and middle schools, most with the purpose of engaging more low-income students.

"The biggest benefit of IB to Mount Vernon High School is that now minority students have the same opportunities for an excellent high school education as the white students from more affluent homes," said Calhoon, recently retired and helping another struggling IB school near her home in Beaufort, S.C. "Any student who wants to excel can do so."

The program, however, has its critics. Some say IB does not align with some of the college courses for which it, like the much larger Advanced Placement program, was designed to substitute. Others say it puts too much emphasis on international understanding. One Fairfax County parent went so far as to say IB "promotes socialism, disarmament, radical environmentalism and moral relativism while attempting to undermine Christian religious values and national sovereignty."

Mount Vernon educators and students say it is the program's academic challenges -- a curriculum that demands deep analysis of selected topics and a 4,000-word paper in the senior year -- that have made it so effective.

IB came to Mount Vernon High because Kristen J. "Kris" Amundson, the neighborhood's representative on the Fairfax County school board in 1993, thought the school needed a shot of adrenalin, something that would convince middle-class families not to leave. She said parents did not like the pitying looks they got at cocktail parties when they said their kids went to Mount Vernon High.

Amundson, a writer and publicist for educational organizations, found an ally on the board in Ruth Turner, who had the same concerns about her neighborhood high school, J.E.B. Stuart. They lobbied other board members, cutting deal after deal to gather support for their pet project. By early 1993, the board had passed a budget item with money for the new program at Mount Vernon and Stuart.

An Early Struggle

Bernadette Glaze thought 7 a.m. was a horrible time to teach IB History of the Americas. The Mount Vernon High teacher absolutely had to have a cup of coffee if any thinking was to occur, and she knew many of her students felt the same. She made her large, first-floor classroom with big windows as comfortable and cozy as she could with some old rugs and a sofa. She set up a big table in the back of the room with a coffee pot, a hot-water pot, hot chocolate, bread, peanut butter and jelly.

It was still a struggle. Her students had little background in Latin America. She tried to make the chapter readings more palatable by using pre-reading strategies -- talking about unusually difficult but important vocabulary words, displaying maps, giving the history a more modern interpretation, as if she were an embedded TV correspondent broadcasting Simon Bolivar's latest battle.

At the end of that first year, Calhoon received the Mount Vernon results in a big white envelope; in many subjects, the grades were distressingly low.

The average score in IB physics was 3.5, below the international average of 4.39. The results in biology were not much better -- an average for the school of 3.69 compared with an international average of 4.39.

And Calhoon was not getting nearly as many minority students into the program as she had thought she would. Barely 10 percent of IB participants the first year were Hispanic or black.

Calhoon and Glaze wanted IB classes to reflect the ethnic mix of the school. To do that, they would have to lure indifferent teenagers into the tougher classes. Through intensive counseling with each student, and the national program Advancement Via Individual Determination that taught study habits, they made progress.

As the program grew, several teachers said, they began to realize that the IB final exams' emphasis on analysis gave them an opportunity to teach in different ways.

Daniel Coast, a biology teacher recruited from a more rural school system in Charles County, struggled to meet IB's demands but found one useful technique. He gave juniors writing their first lab reports a second chance when their first efforts did not meet IB standards.

When two minority boys deft at basketball analysis complained about Glaze's IB Theory of Knowledge class, they did better after she told them: "Your brains know what to do. Just treat Plato as though he were Michael Jordan."

Other students found motivation in unexpected places.

Turning the Corner

At the end of her sophomore year in 1999, Christin Roach's friends were saying they were going for the IB diploma, but she could tell a few were wavering. They had seen the frantic looks on the faces of some IB seniors in the last week before their 4,000-word extended essays were due. They began to realize how hard it would be to do that project as well as pass difficult exams in six subjects.

Class ring selection time came for Roach's class, and one of the options the company offered was a ring with the IB diploma symbol. Many of her friends wanted the distinguished-looking emblem on their rings but were timid about ordering without knowing if they would remain in the program.

Roach ordered a gold class ring, with the IB emblem on one side and the National Honor Society emblem on the other. This, she said, was a way to stay on track. She wore the ring almost every day and even wrote one of her college application essays about that decision -- how it had seemed small and trivial but had far-reaching consequences.

Breigh Miller started the IB program late; her counselor didn't think she was ready for pre-IB in ninth grade, and enrolled her in only one pre-IB course in 10th grade. She decided to try IB anyway. In the 11th grade she took seven demanding courses at once. Her paper in anthropology was so good it was selected as a model for other IB schools.

By the end of the 1990s, Fairfax was on its way to putting IB in eight of its 24 academic high schools. Not all of the IB programs were successful. At W.T. Woodson High School, some parents and teachers revolted in 1999 when they realized that IB was going to replace, not just supplement, the Advanced Placement program.

Years later, Stanford economist Thomas Sowell wrote a newspaper column that said IB was just "one of a series of fad programs" and Woodson was wise to get rid of it.

But such statements were rarely heard at Mount Vernon High. The IB scores increased, and teachers, parents and administrators spoke of a change in the school's image. The IB program put Mount Vernon among the top 3 percent of high schools in the country, as measured by participation in college-level tests.

The program was not cheap, but the educators involved thought it was worth it. In 2004 the cost of test and registration fees, plus an annual school registration fee, totaled $55,906 at Mount Vernon, with none of the fees charged to students. Some Fairfax schools spent nearly that much on their baseball and softball programs.

For Amundson, the school board member who had gotten the money for IB, the defining moment came when she was at a neighborhood party, making the political rounds, and overheard a mother talking to other parents about the local schools.

Some of their children had gotten into private schools. Some were applying to Jefferson, the science magnet. But this mother had her own good news to share: "My daughter has been admitted to that very good IB program at Mount Vernon," she said.

Breigh Miller, 19, a business management major at Georgia State University, got an IB degree from Mount Vernon High School.