As single-sex schools crop up around the nation at record pace -- expanding exponentially since gaining federal funding under President Bush's education bill of last year -- opponents say problems are cropping up at an equally rapid rate.

"Separate is never equal," said Nancy Zirkin, deputy director of the Leadership Conference on Civil Rights.

The Leadership Conference has joined the American Civil Liberties Union, women's and civil rights organizations in denouncing the administration's plans to tinker with Title IX, which for the last 30 years has primarily served to protect women against gender bias in education.

They say they are concerned that funding gender-based schools may reinforce negative stereotypes, perpetuate segregation and ultimately violate the Constitution.

"We don't believe there is enough research and evidence that single-sex education is any better. And we believe that debates like these take away from focusing on improving the current public education system," Zirkin said.

But proponents of such programs say the greater flexibility in Title IX regulations has created a "green light" to experiment with classrooms that may offer better educational environments than traditional schools.

"The Bush administration's announcement in Spring 2002 that it will introduce more flexibility into Title IX regulations has been viewed by the education community as a long-awaited green light," said Thomas Carroll, chairman of the Brighter Choice Charter Schools, one all-girls and one all-boys school, which opened up side-by-side to kindergarteners and first-graders in Albany, N.Y., this year.

"Parental interest is very high, and educators across the nation are very excited about trying this innovation," Carroll added.

So far, five new schools using public dollars have opened up this fall in Albany, Houston, Louisville, Ky., and Philadelphia, bringing the total to 15 same-sex schools across the nation.

Like many critics, Zirkin said there just isn't enough hard evidence to indicate that boys and girls would benefit more from a separate learning environment than a co-ed one.

But researchers say the resources must exist before a study can be conclusive.

"There is no evidence in the public sector, because these opponents are blocking it from happening -- it's a ploy," said Cornelius Riordan, professor of sociology at Providence College. "They are politicizing this issue and subverting the scientific process."

Riordan is currently conducting research on single-sex schools, and said if more pilot programs were established, then perhaps more effective studies could be achieved.

Meanwhile there is plenty of anecdotal evidence that poor, disadvantaged kids benefit from same-sex education, he said, and plenty of data emerging from same-sex urban Catholic schools.

The Young Women's Leadership Foundation, for example, which has established schools for girls in Chicago and NewYork, boasts a college-bound graduation rate that soars beyond the failing co-ed schools in their respective districts.

In the New York case, the two-year-old Spanish Harlem school has gained fame for sending all of its graduates to four-year colleges, save for one young woman who joined the military.

"The experiences I've had here I can honestly say I wouldn't have had anywhere else," said Tanisha Smalls, who was a senior at the New York school and was headed to Williams College when she spoke before an audience in Washington, D.C., last May.

Proponents say same-sex schools not only limit distractions, provide discipline and role models, and foster positive reinforcement, they deal with the cognitive differences among boys and girls without labels and stereotypes.

"Right off the bat, we're seeing benefits of single-sex education in an urban setting within three weeks of opening our doors," said Carroll.

Jocelyn Samuels, vice president of education for the National Women's Law Center, said her group has no problem with giving disadvantaged children who have been suffering from educational inequalities the chance to attend such same-sex schools, as long as safeguards are in place to make sure that the programs are justified and pass constitutional muster.

"We think that Title IX regulations already allow for the single-sex programs," she said. "Our concern is that the Department of Education may try to open up the regulations to authorize the creation of single-sex schools without requiring that they show they are justified. Our concern is that [the administration] lacks the authority to do that. "

The Department of Education is currently drafting rules on how schools will compete for the $450 billion available for innovative single-sex programs afforded in the "No Child Left Behind Act" signed by the president last fall.

The legislation says that as long as "comparable" programs and facilities exist for the opposite gender, the funding should be available to eligible schools.  The department, which did not return phone calls for comment, has recently closed the initial public comment period for revisions and is expected to issue a first draft for public comment before final regulations are issued.