When Schenley High School senior Claire Galpern was in 10th grade, she discovered something important about herself: a passion for social justice.

For the next three years, the 17-year-old Point Breeze resident followed that passion wherever it led her, from tutoring children a few hours a week through the East End Cooperative Ministry, to working summers in the ministry's City Teens program, in their food pantry and soup kitchen. Then, her path took a slight turn when, through her church, she became a regional coordinator organizing anti-racism conferences and workshops for young people.

It was this kind of eclectic, broad-ranging, authentic social activism -- rather than the obligatory two-hours-a-week volunteer job that reeks of resume padding -- that excites college admissions officers.

It certainly must have impressed the admissions staff at Swarthmore College, because Claire has been admitted to the highly selective school for next fall.

Then again, lots of young people today have top grades and scores, and more of them are applying to highly selective colleges -- defined by the National Association for College Admission Counseling as admitting fewer than 50 percent of all applicants -- than at any time in history, so extracurricular activities matter more than ever.

Indeed, Yale University issued a press release boasting that the 2005 freshman class includes an inventor who holds four U.S. patents and a student of traditional Inca healing who is training to be a shaman.

Closer to home, officials at Allegheny College in Meadville, Crawford County, proudly spoke of "Matthew" (not his real name), an incoming freshman who wants to major in geology, minor in German, is a politics junkie, history buff, member of the ski club and does yoga and ballroom dancing.

"We're looking for students who don't have specific talents but who have multiple talents that might be unusual in their combination," said Scott Friedhoff, vice president of enrollment at Allegheny. "And once they're here, we encourage and nurture it."

But don't get carried away and list too much on your college application -- it's quality, not quantity, that makes the difference.

"Select things that really matter to you, so there's a depth of involvement, not a bunch of things that aren't important," said Nancy Wallach, an academic counselor at Allderdice High School in Squirrel Hill.

"What are you passionate about?" asked Howard Greene, a Greenwich, Conn.-based education consultant and author of numerous books on the college admissions process.

"I can't stress that word, passion, enough, whether it's painting, singing, artwork, community service or playing a sport. For college admissions officers sitting there day after day, or late at night, to come across a student writing with excitement and energy about what's important to them, that's the application they're going to notice.

"The really neat, well-rounded kid is not going to do as well in highly selective college admissions as someone who stands out for doing something out of the ordinary."

But don't suddenly start taking fencing in your junior year. That's what experienced admissions officials call an "add-on," or resume padding, "and they can sniff out in a heartbeat what you do just for the college application," added Trevor Rusert, associate director for college guidance at Sewickley Academy.

Besides extracurriculars, there are other factors that can give an excellent student an edge, Mr. Greene said. Children of alumni still are given preference at private colleges and elite public universities.

On the other hand, if you're the first person in your family to attend college, that's something that will help you, too. Excellent students from disadvantaged -- or, in admissions-speak, "nontraditional" -- backgrounds often will merit a closer look.

And finally, of course, athletics play a role, but only in some places, experts said.

Division I colleges -- highly competitive, top-ranked NCAA schools -- spend millions on their sports programs and offer athletic scholarships. If it's a Big Ten school, for example, and you're the next Michael Jordan, even if you're not a great student, you'll probably get in.

But Division III schools -- mostly small, liberal arts colleges -- don't grant athletic scholarships, and when it comes to tipping the balance in the admissions process, athletics can either matter a lot or not at all.

At Denison University in Ohio, for example, "We don't give admissions preference for students who have particular athletic talents," said Perry Robinson, the director of admissions.

But if it's a Division III school that happens to have an athletic program that's No. 1 in the country, that might be different -- just as one with a struggling team might welcome an infusion of talent.

"If a young woman is an outstanding soccer player who happens upon a Division III school whose soccer team is struggling, can that help her? Yes," said Jennifer FitzPatrick, director of college guidance at Sewickley Academy.

"Will it always help her? No. If the coach is recruiting, that can push her over the edge, but if her SATs are 400 points below what's considered acceptable, she can score 50 goals in a game and it won't matter."

Some elite schools, especially the Ivies, do lavish attention on certain sports, experts said, such as lacrosse, crew, fencing, squash and tennis. Cross-country? If you're an otherwise superb student, cross-country might help you at Dartmouth, which dominated this year's All-Ivy competitions, said Mr. Greene. Wrestling? It's not a priority at the Ivies, he added.

What you did during your summer vacation during those four years of high school can make a difference, too.

"It's not cool to 'veg out' during one's junior year summer," warned Rose Feldman of Educational Consulting Services, which helps students and their parents navigate the college admissions process. "But you don't have to go to Tanzania. Pittsburgh has a wealth of things for kids to do," and statewide, there are the Pennsylvania Governor's Schools, a half-dozen selective summer programs in arts and sciences that do carry weight in college applications, she said.

But pricey summer travel programs -- where, for $6,000 a pop, teens live with the natives in Belize while squeezing in some scuba diving -- won't make much of a difference, noted Ms. FitzPatrick.

And other summer enrichment programs for gifted students, like those at Johns Hopkins University's Center for Talented Youth, may nurture a child's interests, but are really only "experiential in nature" rather than something that will help a child get into Harvard.

The exception is summer programs for college credit, which can be costly, although scholarships are often available. Tufts University runs a highly selective summer program in France that, Ms. Feldman believes, can give an applicant an edge -- because it shows he or she is serious about languages.

"This program is about the student saying, 'I love the French language and I want to speak it with greater fluency,' and that gets translated to the college."

"If it's meaningful to the kid, then it's meaningful to the application," added Ms. FitzPatrick.

One more thing: Show you care.

While larger schools don't encourage personal interviews, smaller schools, which are becoming more and more selective, consider it a must.

Beyond great grades, test scores and even a kaleidoscopic portfolio of extracurriculars, Ms. FitzPatrick said, is a real desire to attend the school. With so many students applying online to as many as a dozen schools, "demonstrated interest," expressed in visits, interviews and other ways, can be critical.

But in the end, though, the admissions process at selective colleges remains highly subjective, said Eva Gelman, a Squirrel Hill-based college admissions specialist who focuses on public school students.One admissions question, in particular, may be surprising.

"They may ask, do I want to be this kid's college roommate? If you've got two equally excellent students, an admissions officer's personal reaction may tip the balance."