"JUST SAY NO" has never been easy to say yes to. Whether targeted at teen drug use or teen sex, the message just hasn't been translated into a code of conduct. Now three studies released on the eve of the presidential elections have made the point in similarly stark terms: Abstinence-only sex ed and HIV prevention just don't work.

In September, after polling 4,000 secondary-school students, parents, teachers and principals, the Bay Area-based Kaiser Family Found-ation published some surprising results about the parents' attitudes: 65 percent supported longer, more in-depth sex education than schools currently offer -- a half-semester or more, not the one or two periods most schools provide. Moreover, the folks in this famously progressive port also wanted teachers to tackle such controversial topics as abortion and sexual orientation. More than 80 percent said condom use and other birth-control methods should be covered. Even most parents who want schools to deliver an abstinence message said birth control options should be discussed.

Given the number of teens who are sexually active -- about half of high school students -- the parents' pro-sex ed views don't surprise Tamara Kreinin, president of the Sexuality Information and Education Council of the U.S. (SIECUS). "If you ask parents if they support an abstinence message, they'll say yes," Kreinin said. "But they'll also say they want their children to learn how to protect themselves against pregnancy and STDs." SIECUS' own 1999 poll found that 93 percent of Americans support comprehensive sex education.

The day after the Kaiser report was released, the New York City-based Alan Guttmacher Institute came out with a 10-year retrospective study that offered sobering evidence that the abstinence-only message is increasingly squeezing out info on birth control, sexual orientation, abortion and STD treatment. A mere 2 percent of sex-ed teachers taught an abstinence-only curriculum in 1988, compared to 23 percent in 1999. More than three-quarters of teachers believed those critical topics should be covered, but one-third surveyed said they feared a public backlash if they did.

Even a National Academy of Sciences report commissioned by the CDC lambasted the Clinton administration's lack of leadership on HIV prevention. The study, released the same week as the other two, noted that the government spends $250 million on abstinence-only programs but fails to adequately support comprehensive sex ed and condom availability.

Leslee Unruh, president of the Abstinence Clearing-house in South Dakota, disputes the findings -- and methodology -- of the Kaiser and Guttmacher studies. "We feel it's important who asks the questions and designs the survey because they affect what response you're going to get," she said. "Our studies have shown that parents want an abstinence-until-marriage message. A lot of what's in those other studies I find hard to stomach. Guttmacher isn't taken seriously by most people because it is just an arm of Planned Parenthood." (Planned Parenthood constitutes about 5 percent of the Guttmacher Institute's annual income.)

Still, taken together, these studies deliver a timely message on sex ed and HIV prevention that's hard to ignore. SIECUS' Kreinin said that even the election-obsessed media couldn't ignore. just what the researchers are hoping, as new players move into the White House. "It hasn't escaped our attention that reauthorization of the abstinence-only money will be on the agenda in January," she said. "If officials care about the science and listen to parents and young people, they'll provide a comprehensive approach to sexuality education."