HELENE TREMBLAY has always loved to travel. As a single woman, French Canadian and working in Paris as a television producer, her life allowed her money and time enough to indulge her passion.

But over the years, as she traveled, she longed for more. On her trips she found herself looking into people's eyes, especially the eyes of children, because children in every country stare at strangers and do not turn away. Tremblay wanted to know the people who met her gaze. But she never could.That's how her project started. Wanting to know the people behind those honest eyes grew into the desire to live for a few days with a typical family in every country in the world.

She decided it would take four years, and then she would write a book about it and her project would be over. She didn't let herself understand the scope or importance of what she was doing when she began. She just left for South America with a little money and no publisher. The year was 1981; it was her first step.

Farrar, Straus and Giroux publishing company has just introduced the first volume of her work, "Families of the World, Family Life at the Close of the Twentieth Century: The Americas and the Caribbean."

Now Tremblay is simultaneously doing a press tour for this book; submitting her second book, on the Pacific and Southeast Asia, to the publisher; and preparing to spend 10 months visiting European families by trying to drum up funding. (Previous trips were funded in part by UNICEF and other United Nations agencies and institutions that have funds for research in developing countries - but not in Europe.)

One way or another, Helene Tremblay says, she will do it. She will stay for a few days or a week with a statistically typical family in every country in the world. She will take their pictures. She will write a two-page, hour-by-hour chronicle of their day.

And she will publish a book including their story and the vital statistics of their country - the capital, language, religion, housing conditions (including sources of water, percent of homes with electricity, etc.), family status (including number of people married, number of female heads of household, fertility rate, births out of wedlock, etc.), social indicators (such as life expectancy, percent of births attended by trained health personnel, etc.) and dozens more statistics.

And, Tremblay says, when she publishes her fifth and last volume in 1995, she can't rest until every home in the world where people can read has her books.

"And then the world will have met," she says.

Now, seven years after this remarkable woman set out on her remarkable quest - and three years after she thought the project would be finished - Helene Tremblay understands that she will dedicate her life to this. She will introduce all the families of the world to each other.

Pick up her book in a bookstore, open it anywhere and read. Then put it back, if you can, without buying it. (Incidentally, it costs $30 until Jan. 31; then $35.)

Say the book opens to page 102. You'll meet the Salas Vargas family of Barranca De Naranjo, Costa Rica. Luis Enrique and Maria Tulia (both 41 years old) and their youngest eight children, two nieces, seven cows, six calves, dog, 25 chickens, two rabbits, a cat and a kitten:

4 a.m. During the dry season, from December to March, the wind buffets the wooden house of the Salas Vargas family. Awakened by a particularly violent gust, Luis Enrique shakes awake his elder son, Mario, to accompany him down the hill to milk the cows. Their animals are good milk producers, and today there is enough to fill two large white metal cans. Mario and his father hoist the heavy loads onto their shoulders for the winding climb up the mountain's dirt road to the main highway, where the truck from the cooperative passes by to collect the milk. The evening milking is for the family.

5:30 a.m. In the lean-to attached to the side of the house, Maria Tulia picks up a few logs from the pile arranged carefully along the wall and throws them into the open-fire cement stove that dominates the shed. Electricity is so expensive that she is reluctant to use the electric stove in the kitchen every day. This morning the wood fire will be in constant use. It's three days before Christmas and the Salas Vargas women will prepare hundreds of holiday tamales for family and friends. . . .

In the past seven years Helene Tremblay has stayed with more than a hundred families. She is able to generalize about them. All, all parents want an education for their children, for example. But she doesn't ever write that. She merely chronicles lives. One of the great satisfactions of reading her book is discovering your own truths about human nature.

You can't read it without understanding poverty. "If you want your children to appreciate the standard of living they have in this country," Tremblay says, "just hand them this book."

Memories of certain people sing in her mind. Like the 9-year-old girl in Haiti who was a deaf mute and whose family lived the most poverty-stricken, empty life of any Tremblay visited.

And the mother in the Japanese family. She couldn't speak any of the languages Tremblay speaks (English, French and Spanish) but she could understand and write in English and stayed up at night while Tremblay slept to write her guest letters about her life.

After each visit to a family poorer than she, Tremblay presses money into a parent's hand. Not a large amount by our standards, it's enough for a daughter's dowry, or to build one wall around an outdoor kitchen, or to buy some medicine or a pig. Tremblay's life is richer for having known these families, she doesn't want them poorer for her stay.

Tremblay is 38 years old. Some people would say she is giving up a chance to have a family of her own while she writes about other people's families. But Tremblay takes a larger view of who her family is.

She says, "Last week, I was looking at a sunset in L.A., and I knew the sun was leaving me and going to warm some of my dear friends on the other side of the world."

Some day, she says, it will happen. We will all feel we are part of the same family.