SANTIAGO PORTILLO is the first person in his family to go to college. Now a physics major at the University of California in Santa Barbara, Santiago credits Summerbridge, a unique academic enrichment program, with his success."Summerbridge was the key in allowing me to open so many doors to my future," he says. After completing sixth grade, Santiago was accepted into the six-week, tuition-free Summerbridge program in San Francisco. "For the first time, I felt challenged academically," he says of the intensive program for middle-school students. Ever since then, Santiago has been involved with Summerbridge: He's taken classes and taught classes. This summer he helped launch a Summerbridge program here at the Derryfield School, a private school in Manchester, N. H. After 13 years of success with students in the Golden Gate city, Summerbridge is serving as a model for start-up programs around the United States and even abroad [see article at left]. In addition to three programs in the Bay area, six-week Summerbridge sessions took place in New Orleans and Manchester this summer. By next summer, programs are expected in nine additional cities, including New York, Chicago, Miami, Louisville, Ky., and Providence, R.I. "It's not that complex," national director Lois Loofbourrow says of the Summerbridge concept. "It's just a really rigorous program where kids are teaching kids. They really believe in each other and a lot of creative things happen." Summerbridge targets underachieving students for help. "It is the group of kids who are sitting in class bored day after day because school isn't exciting," says Lynn Sorensen, who has been involved with Summerbridge for 10 years and is director of the new program in Manchester. "These kids are at risk of dropping out of school as much as other kids are - because it's never been interesting to them." Most of the participants are not the type of students who have to take summer courses. "We go to kids and say, 'How would you like to do three hours of homework [a night] during the summer?' " explains Ms. Loofbourrow. "And we go directly to high school and college students and say, 'How would you like to work 12 hours a day and earn [almost] nothing?' These amazing people come forward and they come from all different backgrounds and all different strengths." In 1978, Summerbridge was created by San Francisco University High School, an independent, college preparatory school. The board of trustees wanted to reach talented or motivated students in the community who often get shut out of academically challenging schools because of prohibitive tuition and selective admissions. "Right from the beginning one of the goals was to make sure that underrepresented minorities - especially black and Hispanic youngsters - had better access to stronger programs," Loofbourrow says. But the unique and most widely praised aspect of Summerbridge - using high school and college students as teachers - wasn't in the original blueprint for the program. In the first year, Loofbourrow recalls, three high school teachers taught the core subjects and each had three high school students as teaching assistants. But when one of the teachers was out for several days, the high school assistants took over her class. "Within short order we found that the middle schoolers were working three times as hard for the high school kids," Loofbourrow says. "That was the start of it." Now many of the teachers - like Santiago - are former Summerbridge students who come back to teach others. After a week of intensive training, these student-teachers design their own curricula and start working with students. Mornings are devoted to five academic courses; electives and field trips fill the afternoon. Class sizes are under 10, allowing for concentrated work and attention. The teachers - and even directors - are known by their first names. For the middle schoolers, the ultimate goal is academic success and a commitment to higher education. Ninety-two percent of all Summerbridge students have enrolled in academic high schools. For the high school and college students who serve as teachers, the program provides a chance to explore a career in teaching. Minority teachers are in great demand in school districts all over the country, and Summerbridge's commitment to diversity helps encourage people from many backgrounds to think about teaching as a career. Among the college staff, 64 percent have gone into teaching after graduation. Summerbridge makes a year-long, if not life-long, commitment to its students. Throughout the school year, after-school tutorials and activities are provided. "We take a real mixture of kids," Loofbourrow says. "We're taking some straight-A students who could probably learn on a desert island, and we're taking kids who need a lot of support - and all the kinds of students in between." When Santiago first came to Summerbridge he was making A's and B's in the gifted program at his mediocre public school. But he wasn't challenged and was often disruptive in class. "I remember always talking to people ... because I was able to get through the assignments a lot quicker than some of the other students," Santiago says. "Here I was, 11 years old, sitting in class with nothing to do. You can't just sit still. I find that a little bit difficult to do right now," confesses the 19-year-old. Marco Gonzalez was making poor grades but testing high when he first came to Summerbridge as a middle schooler. "Marco was a great tester but a C student," recalls Loofbourrow, who has seen him grow up since he first came to Summerbridge. "I don't think he had any idea how smart he was." Now Marco is a senior at the University of California, Berkeley, and helped start the Manchester program this summer. On the last day of the workshop here, Summerbridge students talk enthusiastically about their six-week experience. "Even though the homework is heavy, it's fun," says David Flagg, an 11-year-old student. Last school year when David was in fifth grade he rarely had homework. And when he did, it only took him about five minutes to complete. During Summerbridge, he has spent up to four hours a night on homework. Alyssa Brown, another student, says it's easier to do that kind of hard work for younger teachers. "You want them to think of you as a friend," she explains. "They know how you feel and they can understand you better," says Monique Lafond about the Summerbridge teachers. "The adults - what few there are - are like conductors," Loofbourrow says. "We bring the different parts of the orchestra together, but how they play each summer is unique." Summerbridge is funded by corporate donations and grants. The headmaster of the Derryfield School raised $65,000 from local sources to start the program. Once it's up-and-running, the cost is about $1,000 per student, including the summer workshop and year-round tutorials. "The high school and college students basically are volunteers," Loofbourrow says. "We would love to raise more money from foundations to give them what they really earn during the summer," adds Sorensen. Santiago acknowledges that he could easily be making much more money this summer by working as an intern at an engineering firm. In Manchester, teachers are paid a total of $750 for six weeks of 12-hour days. But coming back to teach at Summerbridge is not about making money, Santiago and Marco say. They want to give back some of what they got out of Summerbridge. "It gave me a new outlook on education and allowed me to go to a good high school which launched me into college," Marco says of the program. After Santiago's sophomore year in high school, he wanted to teach at Summerbridge for a second time. But Loofbourrow encouraged him to apply to the Hotchkiss Summer Program at an elite prep school in Connecticut. "I took three hours of physics a day, and I liked it," says Santiago, who is now gaining an undergraduate degree in the discipline. "We tell kids about opportunities that they wouldn't hear of ordinarily," Sorensen says. "Summerbridge is like a big family where you try to help everyone reach their potential."