“People generalize that Asians are all smart, and their kids do well,” Mr. Chen said. “But that’s a misunderstanding because they don’t see the ones that are struggling in school. They’re invisible.”  APEX was started by five Chinese-American friends who wanted to help families from similar ethnic and cultural backgrounds. Alex Tsui, 45, a dentist from Lexington, Mass., who is the president of APEX, said that other mentoring programs like Big Brothers Big Sisters had established relationships with the black and Latino populations, but that no one in the early 1990s had consistently focused on the needs of Asians.  So Mr. Tsui and his friends — the others were a lawyer, an auditor, a financial analyst and a strategic planning consultant — set about filling what they saw as a void. They urged their friends and acquaintances to give up their nights and weekends to serve as mentors and bought supplies with a $2,000 grant from a company that encourages volunteer work. They used their workplaces, like the Asia Society, for meetings, unbeknown to their employers, because they could not afford to rent office space.  “We leveraged all our work contacts off hours,” Mr. Tsui said. “The Asia Society never even knew we had so many events there on nights and weekends.”  APEX started with 35 11th graders in Chinatown, who signed up after they heard about the program at their neighborhood schools. The notion of mentoring was so foreign to the culture that the group struggled to find a Chinese translation. They considered “lao shr,” or teacher, but that was not quite right. They settled for “da ge,” or “big brother,” even though that roused suspicions among some parents because the phrase is also slang for a gang leader.  Mr. Tsui said the group soon outgrew its makeshift meeting places, as word of the program began to spread. For instance, APEX once organized a scavenger hunt at the Metropolitan Museum of Art that drew more than 120 Asian-American mentors and students. It also attracted the attention of a museum security guard who threatened to eject them because they did not have a group permit. (He relented.)  APEX set up a formal board of directors, and its members began fund-raising to finance an expansion. Mr. Tsui spent so much time on these efforts that the partners in his dental practice told him that he seemed more interested in APEX than his day job. Eventually, he was the only one of the five founders still active in the group; the others moved out of state or moved on with their lives.  Today, APEX has enlisted more than 100 volunteers and hired a full-time staff of five to run its programs out of a 2,000-square-foot office in the garment district. The organization’s annual budget of $484,000 is financed through donations and grants.  Most of the students who join the program stay with the same mentors until they graduate from high school and often maintain close friendships with them long after that. As much as possible, APEX tries to match students with mentors who have similar interests and experiences.  Eric Cheng, 15, a 10th-grade student at the Urban Assembly Design and Construction High School, said he decided to follow in the career path of his mentor, Preeti Sriratana, an architect, after the two spent hours visiting museum exhibitions and talking about modern design. For a gingerbread-making contest at the APEX holiday party, they used graham crackers and frosting to build a three-foot replica of the Empire State Building.  Until he met Mr. Sriratana in 2004, Eric said he thought only about playing basketball and, if that failed, getting a job as a sanitation worker because his mother told him the pay was good and he could retire early. “I never had a mentor before, and I’m a person who likes to try new things,” he said. “Preeti, he’s pretty cool.”  Mr. Sriratana, 30, whose own parents are doctors, said that he tried to show Eric that there were many things that might interest him, and that with hard work, he could pursue any of them. Though Mr. Sriratana clocks an average of 60 to 80 hours a week at work, he still manages to spend every other Saturday with Eric.  “Sometimes, I wake up on Saturday morning, and it’s the last thing I want to do,” he said. “But once you’re out there, it’s fun. It’s still tiring, but there’s a certain sense of fulfillment you get.”  For Mr. Tsui, the success of APEX has been a different kind of learning experience. He started the program with no more than good intentions and a desire to make an impact, and 16 years later he has come to realize how much more work still needs to be done to help people from less advantaged backgrounds.  “Although spirit and determination can overcome much, it cannot always overcome all,” Mr. Tsui said. “In that sense, I’ve learned the rewards of making a difference and the limitations of what one can do, given the constraints of society with all of its inequities.”  A version of this article appears in print on , on Page B9 of the New York edition with the headline: Asian-Americans Build a Network To Help Students. Order Reprints| Today's Paper|Subscribe
A program has grown from a neighborhood project into one of the largest mentoring programs for Asian-Americans in New York City.