About 22 percent of all children in the United States under six live in poverty, well over the 14 percent poverty rate for the population as a whole. For black children, the poverty rate is one in two.

More than 500,000 children grow up in foster homes and institutions. Fully 10 million children have no known source of health care.

Nearly half of all small children have mothers who work outside the home. About 10,000 babies die each year from sudden infant death syndrome; 25 youngsters drop out of high school for every 100 that graduate.

These are a few of the items about children gathered by various agencies of the government -- from the Census Bureau to the Labor Department.

But while much is known about the nation's 62 million children under 18, there is a great deal that isn't known or hasn't been pulled together in one place as a basis for policy.

How do programs interact on each other? What do we know about the causes of crime, success in school, success on the job, family stability? What is the impact of being reared in a home without a father?

It was questions like these that impelled Rep. George Miller (D-Calif.), with Democrats Henry A. Waxman (Calif.), Ted Weiss (N.Y.) and Corinne C. (Lindy) Boggs and Republicans Henry J. Hyde (Ill.), James M. Jeffords (Vt.) and John H. Rousselot (Calif.) as chief co-sponsors, to push through the House last September a resolution authorizing a special study committee on children.

The new unit, which won't come into being formally until the next Congress is organized, won't have any power to report out bills and therefore can sidestep the danger of legislative clashes with committees that do.

Its primary function is to look at the hundreds of federal, state and local programs that affect children and get an overview of how they fit together, how changes in one affect the way the others work.

The aim is to paint a comprehensive picture of everything that is known about children with accurate and careful statistics that cut across programs, disciplines and issues. The economic status of children. Their health. What makes for success? What will strengthen family life? Where do programs work at cross-purposes with each other?

Backers say there was no organized opposition to the concept of creating a study committee, but the House is often reluctant to create new units and the job of Miller and his allies was to overcome this institutional obstacle and convince people a useful purpose would be served.

By the time the Miller resolution reached the floor Sept. 29 it had a tremendous head of steam: endorsement by 150 organizations and a big lobbying effort that included groups like the Child Welfare League, Children's Defense Fund and many religious and social welfare groups; 229 co-sponsors; assent of the leadership of the House.

Miller has worked on children's issues for many years as a member of the House Education and Labor Committee and he led the House debate in tandem with Rep. Shirley Chisholm (D-N.Y.), who represented the House Rules Committee.

Plenty is known about children, they told the House: they make up half the beneficiaries of food stamps and 70 percent of welfare; 1 in 5 lives in a one-parent family; more than 800,000 small children have no adult supervision during the day. In many ways, the government is generous to children, spending large sums on their needs.

The problem is, Chisholm said, 13 House committees and dozens of subcommittees have jurisdiction over different programs affecting children, and each one looks mainly at its own piece of the action.

What is needed, Miller said, is a study group to pull all information together and to develop new information.

So far, House Democratic leaders have not publicly stated who will be named committee chairman. That won't come until formal action is taken to set up the committee next year. But Miller, who organized the coalition, is obviously a key candidate.