ONE OF THE HARDEST tasks for those of us who spend our time trying to learn about and tell others about the Third World is both seeing and showing the faceless global majority as individual people who are both interesting and worth caring about.

We have statistics that tell who is poorer than whom, whose children die younger, who doesn't get enough to eat. We know exports and imports, development plans and problems, political allies and enemies.

What usually is not found in the studies, or the newspaper reports, is a sense of the individual lives and aspirations that make up the statistics.

In Children of the Incas , writer-photographer David Mangurian uses the simplest way possible to get behind the studies and introduce us to a small sliver of life in a faraway land. He lets the people -- one Indian family, living in an isolated village in the Peruvian highlands -- introduce themselves.

The story of Juan Dionicio Quispe, his wife and five children is told through Mangurian's pictures, taken during four days and nights living in their home, and the words of Modesto, Quispe's 13-year-old son.

The technique is not a new one. The Inca-descended Indians of South America's "altiplano," the miles-high plateau spanning the border between Peru and Bolivia, have been amply photographed with their llamas, their thatch-roofed adobe houses and their strange bowler hats.

As for the written part of this slim volume, Oscar Lewis, in books like The Children of Sanchez and La Vida , long ago perfected tape recorder sociology, using the words of Mexican slum dwellers to describe their lives in their own terms.

The considerable charm of Children of the Incas lies in the combination of words and pictures, and the stark and simple integrity of Modesta's unemotional recounting of his world on the high plains.

Mangurian's introduction, written in short-sentence, almost primer style, gives the necessary statistics. The Quispe family lives in the town of Coata, "not even a dot on the map of Peru," 12,000 feet above sea level near Lake Titicaca.According to a 1975 census, it is home to 104 people, 192 sheep, 92 pigs, 80 cows and 28 chickens.

The family makes its living running a small store, tending sheep owned by someone else, making handicrafts and sharecropping. The women of the family speak only Quencha, the Inca language.

Modesto, who works tending sheep on the arid limitless plains vividly shown in Mangurian's wide-angle black and white photos, speaks the Spanish he has learned in school.

"I was born here in the highlands," he says. "Everyone lives so far apart here. It's very quiet. There's no shouting. Hardly anything exciting ever happens. It's as if the people were standing around in a daze."

Modesto's spare descriptions of daily life speak volumes about poverty, politics and the human spirit. "I used to have two other sisters," he says matter of factly. One year, when they were ages three and five, they died from and unknown disease that struck a number of people in the village.

"My father said nothing," Modesto recalls. "He went to hear mass. And he cried all week. What bad luck that they died."

Coata, Mangurian explains, serves as a sort of district administration center, and his photographs show the local officials standing stiffly at attention in dingy offices straight out of the last century. Still, politics is politics everywhere. "People aren't united now," says Modesto. "In Coata, the mayor doesn't get along with the district governor. The judge doesn't get along with the mayor because he wanted to be the mayor. Nobody cares about the town. They only care about themselves."

Modesto, who once lived with his uncle in a larger city, wants out. "I'm tired of living here. I want to go to the city. I want to study. I'd like to become an engineer. Then I could do something for Coata. Build schools and parks, and pave the streets. The town needs electricity, water, a stadium . . . . I don't know what heaven is like. But I think heaven must be a city."

Children of the Incas is a nice book, both for children themselves, and for anyone who wants to see the faces behind the statistics of one faraway country. They are remarkably familiar.