SAN FRANCISCO — The computers of the U.S. Census Bureau collected data about same-sex couples in the last census and, in effect, responded: "does not compute."

Any woman who reported she lived with a wife in the 2000 census, or any man who said he lived with a husband, was considered a statistical glitch.

"The software changed it to 'unmarried partner,'"‰" said Bay Area census official David Lloyd. "The software was based on policy, the policy being that same-sex marriage was not legal in 2000."

That changed in June when the bureau decided to tabulate same-sex couples in whatever way they identify themselves in the 2010 census. The agency hopes to improve accuracy and also regain the trust of gays and lesbians who considered ignoring the once-a-decade count because the federal government does not recognize their marriages.

"It's a great first step," said Geoff Kors, executive director of gay rights group Equality California. "We're pleased that we're being counted."

The questions that the Census Bureau will be asking every American about their household relationships have not changed. Whoever fills in the questionnaire this spring must say who else lives in the home, whether that be a husband or wife, a grandparent, child, sibling, in-law, roommate, boarder or unmarried partner.

What has changed, however, is how the government uses the raw information it collects.

Instead of ignoring same-sex couples who identify as married, the Census Bureau has tweaked the software so those couples are counted.

That's a big shift, said Lloyd, a longtime San Francisco resident who was hired by the bureau as an outreach coordinator promoting census participation among the LGBT community of Northern California.

"People who don't know about this, the minute we explain it, it's a uniformly positive response," Lloyd said. "In general, the community sees this as recognition by the federal government that didn't exist before."

Most states continue to deny same-sex couples the legal status of marriage, including California with the passage of Proposition 8 last year, but Lloyd said gays and lesbians in those states might still report living with a married spouse of the same gender.

"If you view yourself as married because of your relationship, and you aren't married, perhaps you'll check the married box," Lloyd said. "We want people to view themselves as they see themselves."

The federal Defense of Marriage Act, passed in 1996, prohibits the federal government from legally recognizing same-sex marriage, which is why the architects of the last census went out of their way to exclude same-sex couples who declared themselves married, Lloyd said. Obama administration lawyers have interpreted the act differently, viewing the census questions as a way of capturing and reporting information rather than as an extension of a specific law or regulation.

"It recognizes the reality of the legal ambiguities around same-sex marriages right now in the United States," said demographer Gary Gates, who studies sexual orientation at the Williams Center at UCLA.

Kors said that in future counts, he and many other gay and lesbian advocates would like to see questions about sexual orientation and gender identity, but that kind of change is more controversial and likely to require an act of Congress.

In the meantime, most gay rights groups are promoting the census as a way of improving the visibility of same-sex couples and also because an accurate count means states and local governments get federal funding that is proportional to their population — something that helps everyone who lives there.

IF you go
  • What: 2010 Census LGBT Community Roundtable
  • When: 12:30 p.m. Thursday
  • Where: San Francisco LGBT Community Center, 1800 Market St., San Francisco
  • Who: Speakers include Tim Olson, assistant division chief for the Census Bureau's Field Division; Gary Gates, scholar with the Williams Institute at UCLA; Geoff Kors, executive director, Equality California; Lynn Sorgenfrei, assistant regional census manager.