* The Group House. "It's so hard to meet people in Washington," says Nancy Brandwein, co-author of The Group House Handbook (Acropolis Books Ltd., 254 pages, $6.95). Besides the economic advantages of living in a group house, "you find companionship, there's just so much more potential to meet people. If you're moving to a new city, you have no idea how quickly connections can be made," says Brandwein.

According to Census Bureau statistics released in November, nearly 7.4 million people (3.3 percent) lived in households of two or more persons not related by family ties. A large number of those households consisted of people of the same sex sharing living quarters, such as group houses or friends sharing an apartment.

Brandwein, 24, and co-authors Jill MacNeice, 27, and Peter Spiers, 28, have pooled their knowledge of Washington--and that of about 200 other singles--and assembled practical information on the many aspects of group-house living: the initial decision, how to chart the murky waters of varied expectations and systematic approaches for dealing with the critical issues of finances, cleaning and food. The well-organized handbook includes a special section for senior citizens interested in group-house living.

"If you don't have a sense of humor," says Brandwein, "you're not going to survive." Essential to successful group living is a blend of "compromise, tolerance and flexibility."

The major problem, she says, is "differing expectations that aren't talked about, no communication, keeping little contracts in their head. Even if it's awkward and deliberate, talk about what the house wants at the very beginning. You can do a house profile on a sheet of paper. Most houses dissolve because of lack of communication.

"Those group houses that were successful had a lot of meetings, close contact. They didn't let problems fester. They were open about it."

* Celibacy. Although secular celibacy is not a new phenomenon, it is increasingly regarded as a healthy alternative, according to anthropologist Patricia Whelehan and psychologist F. James Moynihan of the State University College at Potsdam.

"The ideology of the 1960s sexual revolution theoretically allowed for sexual choices," say Whelehan, 35, and Moynihan, 37, in their joint paper, "Secular Celibacy as a Reaction to Sexual Burnout," presented at last month's American Anthropological Association Meeting in Washington. "In reality, however, it demanded goal-directed sex for both men and women. Regardless of how different traditional and sexual revolution mores appear to be regarding specific issues, performance pressures have persisted."

Today's celibates, aged mid-twenties to 40, are choosing a nonsexual life style, a time out to reorder priorities, say the paper's authors, "although we have no raw numbers or percentage of the population who are doing so." Typically, they are "involved in relationships in which they express their sensuality--caressing, holding and hugging. Sensuality and relationships are important; sexuality, at least for the moment, less so."

* The new urban woman. "A new generation of urban female achievers seek challenging, rewarding jobs, will probably marry later than their rural counterparts, and place more value on a man's dedication to an interesting occupation than on the amount of his paycheck," according to a 69-item questionnaire completed by 500 members of the Mademoiselle Career Marketing Board, a national network of working women. The average age of the respondents was 29.

Among the findings, which appear in the March issue of Mademoiselle:

* Almost 75 percent of those who have lived in a city three years or more report a high level of satisfaction with their work.

* 59 percent consider supportiveness of their career to be a man's most important quality, in contrast to the women of 20 years ago who looked for "support" rather than supportiveness.

* The city woman is most likely to marry between the ages of 29 and 32, significantly later than most women in America (for whom the average age is 22).

* Although a majority of single city woman (55 percent) live alone, the happiest single woman is one who lives with a roommate. According to Robert Weiss, professor of sociology at the University of Massachusetts, this may relieve what he calls "social isolation."

* Quick Takes. Conversations' lecture series: Joseph E. Robert Jr. and Veronica Pickman speak on "Equity Rent" Sunday, Feb. 6, at 4:30 p.m. (The Seaport Inn, 6 King St., Alexandria); Penny Stock News publisher Jerome M. Wenger talks about the investment community of penny stocks, Sunday, Feb. 13, at 4:30 p.m. (Asti Roseto's, 7940 Wisconsin Ave., Bethesda.) Lecture and hors d'oeuvres, $15. Cash bar. Reservations required. Call: 657-3357.