Ms. Vincent, who lives in Harlem with her 3-year-old daughter, is enrolled in an experimental program designed by the nonprofit Manpower Demonstration Research Corporation.

"The cream of the crop can figure out a new system," said Gordon Berlin, a senior vice president of the nonprofit Manpower Demonstration Research Corporation, which evaluates welfare experiments.

Studies of such programs by the Manpower Demonstration Research Corporation, a national nonprofit group that evaluates welfare experiments, have found they do little to better participants' job prospects.

An April evaluation of how the new law is working in California, by the Manpower Demonstration Research Corporation, a not-for-profit group in New York, showed results that experts said were encouraging.

"I think that if we introduce time limits on welfare, we'll have more women and children living in Grand Central Station" said Dr. Gueron of the Manpower Demonstration Research Corporation.

A new experimental program, designed by the nonprofit Manpower Demonstration Research Corporation, is trying to break the cycle.

Part of the money will help teen-age mothers learn basic skills through the New Chance Program of the Manpower Demonstration Research Corporation, a national research organization that develops programs for the needy.

But studies by New York's Manpower Demonstration Research Corporation showed that some of them managed to cut caseloads by a few percentage points, raise employment and save a few taxpayer dollars.

"This plan is a step toward ending the current welfare system," said Judith Gueron, president of the Manpower Demonstration Research Corporation, a New York firm that evaluates welfare programs.

The latest findings from Ohio's experiment in using financial incentives to keep teen-age mothers in school, reported last month by the Manpower Demonstration Research Corporation, are only marginally encouraging.