Welfare, Children and Families: A Three City Study is a longitudinal study of children and their caregivers in low-income families that were living in low-income neighborhoods in three cities in 1999. The purpose of the study is to investigate the consequences of policy changes resulting from the Personal Responsibility and Work Opportunity Reconciliation Act of 1996 (PRWORA). The survey was designed to provide information on the health and cognitive, behavioral, and emotional development of children and on their primary caregivers' labor force behavior, welfare experiences, family lives, use of social service, health, and well-being.

The Embedded Developmental Study (EDS) was developed to gain a more detailed and valid picture of the environments and processes that affect children during early childhood that cannot be obtained through standard survey instruments. The EDS was focused on preschoolers because children in this age range embark upon developmental paths that, in turn, drive later intellectual, social and physical growth. Mothers also face challenges during this period in providing appropriate warmth, limit setting, and learning opportunities, as well as in meeting the great time demands of caring for preschool children and finding appropriate alternate care. The survey gathered detailed, process-oriented measures that provide information not easily collected in standard surveys. The EDS contains three components: (1) an additional home visit with mother and child, which includes videotaped tasks for the child and the mother-child together, as well as an additional mother interview; (2) a visit to the child's primary care provider (other than the mother), which includes observational ratings of the care and an interview with the childcare provider; and (3) an interview with the child's biological father. The EDS was undertaken with nearly all children ages two to four in the survey. It mirrored the main survey in its timeline; with all portions of the EDS completed while the main survey was conducted in the field.