Three years ago, when Claudia Testa was in eighth grade at South Lakes Secondary School in Reston, she read all 38 of Shakespeare's plays.

The next year, when she moved to Herndon High School, she had a rude awakening of a reverse kind: Her ninth-grade English teacher expected to "work up" to Shakespeare--one play at the end of the course.

The difference was that at South Lakes, Claudia was part of an academically ambitious program for exceptionally bright children. The so-called GT--gifted and talented--program in Fairfax County ended at eighth grade, dropping participants such as Claudia rather abruptly at the high school door.

This fall, for the first time, Fairfax County will implement a sweeping GT curriculum in all high schools. The decision has sparked an unexpected debate in a county that prides itself on the quality of public education. At issue are the rights of gifted students to special education--and the rights of the children who may be left out.

"We resented the privileges they seemed to get," said Elizabeth Morgan, 14, who was a non-GT student at Haycock Elementary school. Even though she was student body vice president there and was supposed to encourage cooperation, Elizabeth said she didn't like the fact that GT students got special field trips to the Kennedy Center and other places and were given more training in science.

"I wouldn't say I was jealous, but being called non-GT was a low blow," said Elizabeth, now a freshman at McLean High School, where she is enrolled in three GT classes.

GT classes are elitist, charges her mother, Barbara Morgan, chairman of a concerned parents' committee. Critics say the school board is establishing an academic caste system that will drain off teachers and resources, place too much pressure on gifted children and in effect denigrate other students as "nongifted."

Proponents argue that GT will not only meet the special needs of the academically precocious but increase the challenges for all students. "We're not taking anything away from anybody," says Barbara Rosenfeld, chairman of the county school board's advisory committee on gifted and talented children. "We want to raise the level of education for everybody."

The idea of targeting children for special programs is hardly a new practice. Fairfax set up GT programs in the third through eighth grades in the late 1960s, and at the high school level, advanced placement and college preparatory classes are standard fare.

Some parents say they fear that segregating children by ability erects a barrier between teen-agers at a time when sensitivity to social status is at its highest. Others worry that separating the "brains" from the rest of the student body only weakens the system. But in a time when competition for college and jobs is intense, the consensus seems to be that children should be helped to excel.

"I just don't think it's true that if a child is bright, he will do well in ordinary circumstances," Rosenfeld says. "We have a responsibility to encourage children to develop whatever potential they possess."

Yet in elementary and intermediate schools, where GT tends to be a separate mini-curriculum rather than a course-by-course alternative, the selection of "gifted" children has produced tensions, with pre-teens uncomfortable with the distance between the academic fast track and the locker rooms of youthful society.

At Langston Hughes Intermediate School in Reston, GT students complain that the other children refer to them as "weird," "GT freaks," inhabitants of the "brain ward."

"They think of us as just 'brains,' " complains seventh-grade GT student Hal Mangold. "They don't think we can do athletics or anything. It's stupid."

"When we're together, we can defend each other," says fellow GT student Michelle Schroeder. "But if you're alone in the locker commons and somebody calls you a freak, there's nothing you can do about it."

Anna Karabelas, a rookie GT, says, "It seems like they have a spite against GT students." Even in regular classes, she faced hazing over her consistently good grades.

"Your friends accept you the way you are," says Vicho Vasquez, also a seventh-grade GT student in Reston. "It's the people who don't know you who don't understand."

But it's not only students who sometimes taunt GT students with the label. Jennifer Mohan, and several other GT students, recalls a non-GT teacher who corrected her curtly, "You're in GT; I expect you to know that."

Morgan and other parents, many of whom have both GT and non-GT children, have formed a committee to pressure school administrators into investigating the psychological effects of GT "labeling." In the 16 years since Fairfax implemented GT programs, they point out, no attempt has been made to follow students' progress in high school or college.

Proponents agree the GT program should be evaluated. But so far, Superintendent William J. Burkholder has responded only that "years of experience" with the third- through eighth-grade programs "convinces us that the program does not have a negative psychological impact upon either those students who participate or those who do not."

Gifted and talented is "a terrible phrase, but we can't find a better one," acknowledges Natalie Testa, Claudia's mother and now president of the Fairfax County Association for the Gifted. "If we say 'academically' anything, we've left out a whole group" of artistically oriented children.

"Eliminate the label," says Paul Plawin, a member of Morgan's committee, "or label the course, not the kid."

The county's decision to encourage high schools to provide special GT courses, rather than beef up traditional honors or advanced placement classes, set up another debate over which students would be eligible to participate. Trying to defuse the charges of elitism, Rosenfeld says the number of students who have so far been approved for GT classes is "enormous, beyond any expectations--25 to 30 percent" of the student body. "That's not elitist; if anything, it's too broad."

"In that case, why bother?" asks Eva McGeehan, a Reston parent who is critical of GT.

Critics say the problem is that GT students are chosen only on the basis of previous performance: scoring in the 98th percentile of standardized tests or at least 140 on IQ exams, graduating from GT programs in elementary school, amassing a high grade-point average.

But Rosenfeld says administrators will bend over backwards to find students who don't meet the obvious tests. "Kids change; they may have been overlooked, they may be late bloomers, they have moved in, they may have cultural differences--they may not have been getting the right advice."

"Why have a pool at all?" asks Patty Collins, whose daughter was offered, but declined, GT placement. "Why not just list the classes on the course selection sheet and let the students sign themselves up?"

Rosenfeld says that, in effect, a student can do just that. "If a kid has an interest in a particular subject and nobody's picked it up, he can write an essay to the committee, or appeal to the principal."

"Do you know what you're asking of a kid?" retorts Collins, who says the fear of being rejected would inhibit too many students.

At issue is not only what is being asked of students, but for what reasons. Many parents, according to critics, seem more interested in the way GT credits brighten a high school transcript than in the intellectual challenge the courses themselves may have to offer. Testa, asked to address the parents of prospective GT students at Herndon High, expected "maybe 50 parents;" instead, she was "flabbergasted" to see more than 600.

Fairfax has opted to integrate its GT program in the high schools rather than establish a separate intensive school like The Bronx School of Science, the original model, or the District's two-year-old Banneker Senior High. This partially defuses the charge that good teachers will be siphoned off to the GT classes ("leaving nothing but old coaches," as one parent complains). It also reduces the concern voiced by some teachers that all the bright students will be siphoned off.

Because the program is still in the planning stage, there are no hard-and-fast rules about what goes into a GT course of study. There is some evidence, however, that the effects of such a program "trickle down" through the whole system. In Prince George's County's Eleanor Roosevelt High School, where the GT students represent 40 percent of the student body, tests scores for all students have improved over county and national averages.

Assistant supervisor Beatrice H. Cameron says Fairfax settled on a course-by-course system because by the time they reach high school, students have more specific abilities and interests: "A kid may be a first-rate mathematician and have absolutely no interest in the humanities." Administrators also hope that the mixed curriculum will blur the line between GT and other students.

Yet, what the GT students seem to want may be impossible--both to stand out and to mix in. "We all want to learn," says seventh-grader Holly Holzer. "Each of us has a goal, to be a doctor or a famous scientist or something. That's why we're here."

But intellectual recognition is no substitute for social acceptance. As Michelle Schroeder wonders, "Why can't we just be regular kids?"