Parents of students in the D.C. school voucher program generally believe that they are benefiting academically from the private-school grants, but some think their children have been stigmatized by teachers and classmates, according to a new study.

The study by the Georgetown University Public Policy Institute, released yesterday, was based on focus group meetings with 45 parents and 23 students in fall 2004 and spring 2005, only a small fraction of the 1,027 children who participated in the voucher program in its initial year. Now in its second year and with an enrollment of about 1,700 students, the program provides federally funded scholarships of up to $7,500 for low-income District children to attend private or parochial schools.

Although the report is not a scientifically valid survey, it offers insights about issues that parents think should be addressed in the remaining years of the five-year federal experiment, said Patrick J. Wolf, an associate professor of public policy at Georgetown and one of the study's authors.

"The study sends a signal to the broader education community what low-income D.C. parents are looking for in their education environment," he said.

Wolf also is involved in a separate study that will analyze test score results to determine whether voucher students are outperforming their counterparts in public schools. That report, which is federally mandated, will not be completed until 2007.

The authors of yesterday's report, called "Parent and Student Voices on the First Year of the D.C. Opportunity Scholarship Program," interviewed parents of students in grades 3 through 12. Although most parents thought their children were performing better academically than they had at their old public school, some thought the students were being treated unfairly, the study said.

The federal voucher law and the policies of the Washington Scholarship Fund, the nonprofit organization that runs the program, require that the identities of voucher students not be revealed to anyone at their school other than the principal and admissions staff. But some parents said they believed their children's status had been divulged to others, according to the study, which did not name any of the families or schools involved.

"When she first got there . . . she was having a little bit of adjustment problems and the teacher told her in front of the classroom, 'If you don't stop acting like this, remember, you are here on a scholarship and we could put you out,' " one parent was quoted as saying.

Another parent told the study's interviewers, "There is elitism in the parent organization 'cause I went to a meeting and I was pointing out some issues and a parent just said, 'Why don't you leave?' "

Wolf said such comments came from a small minority of the parents interviewed.

Shirell Simmons, a voucher parent who did not participate in the Georgetown study but spoke to a reporter yesterday about her child's experiences, agreed that stigmatization is a problem. Her 9-year-old daughter attends Rock Creek International School in Northwest Washington.

She said that other children shun her daughter and that last year another student told her child: "Why do you dress like that? You dress like a thug. . . . You look like one of those hoodlum rappers."

Simmons said that the school has been unresponsive to her concerns. "I feel the administration isn't supportive of voucher students," she said. "They're treated as second-class citizens."

Josh Schmidt, director of admissions and advancement at Rock Creek, denied Simmons's allegations. "Voucher students are no different from any other student," he said. "We are race-blind, income-blind and religion-blind. We support every student in every way possible."

Sally Sachar, president and chief executive of the Washington Scholarship Fund, declined to comment on Simmons's case. But she said the organization takes confidentiality breaches and conflicts between parents and the schools seriously.

Sachar said the organization added language this year to its contract with private schools that specifically calls for them to follow the confidentiality policy. She said the scholarship fund also has established a citywide "parent empowerment group" to help voucher parents resolve problems at schools.