The overall purpose of this study was to examine the influence of variations in early childcare histories on the psychological development of infants and toddlers from a variety of family backgrounds. This general objective was addressed through a prospective, longitudinal study of the experiences of 1,364 children and their families, which took into account the complex interactions among child characteristics and those of the human and physical environments in which the children were reared.

The specific research aims were as follows:

• Examining the relationship between infants' childcare arrangements (defined in terms of hours, type, quality, and stability of care and the age at which the child entered care) and children's concurrent and long-term development. Specifically, the study investigated the association between children's experiences in childcare and their social, emotional, language, and cognitive development. The social-emotional assessments included measures of attachment, independence, compliance, behavior problems, prosocial and antisocial behavior, and general competence in interacting with peers. Cognitive variables include general developmental level and problem solving skills. Language assessments incorporated measures of children's expressive and receptive communicative competence.

• Examining whether the social ecology of the home moderates the effects of childcare, i.e., whether children from different home environments are differentially affected by similar childcare experiences. The study examined the moderating effects of parents' values and attitudes, psychological adjustment and mental health, stress and social support, child-rearing practices, time use, interactions with the child, the marital relationship, and family demographics.

• Examining whether individual differences among children moderate the effects of infant care on child development. The study examined the moderating effects of such child characteristics as age, sex, health, birth order, and temperament.

• Identify demographic and family characteristics associated with families' childcare decisions. The study examined whether specific childcare arrangements are related to the parents' social class, marital status, psychological adjustment and personality, child-rearing values and attitudes, parenting practices, stress, social support, marital relationship, and the availability of childcare in the community.

• Provide a natural history of infant care in the 1990s, and help establish a baseline of data pertaining to the kinds of care being used by families. Whereas other national databases, such as those provided by the United States Census Bureau, provide static estimates of the number of children in different types of childcare, this network study supplements that knowledge with longitudinal data on successive enrollments into day care at various ages, patterns of arrangements used concurrently and over time, and the stability of arrangements during the first three years of life. One of the most valuable aspects of the collaborative study is the opportunity it provides to obtain a more complete and accurate picture of patterns of infant care used by families today. Census surveys use only gross categories of care (e.g., center vs. in-home). In this study, more fine-grained information regarding the types of centers and home-care facilities was gathered.

• Examine the consequences for families of maternal employment and childcare choices. Family relationships, parental mental health, family stress, and so on, are not just inputs to child development or moderators of childcare effects, they are also outcomes. High-quality childcare may alleviate family stress and enhance parental adjustment. Low-quality childcare may add to the stress parents experience. Although the main focus in the study was on the effect of childcare on the child, the study also examined the effect of childcare on the family.

• Identify demographic characteristics of childcare associated with childcare quality. Of interest to policy makers is another aspect of the study, the investigation of those regulatory characteristics that predict care of higher quality. These characteristics included the level and type of caregiver training, the size of the childcare group, the auspices of the childcare program (public/private, profit/nonprofit, independent/chain, employer-sponsored/church-based), whether the facility was licensed or unlicensed, the level of payment and fees, and whether the caregiver was a relative of the family.