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Study Overview

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​Note: This study is complete. The information on this page is provided for historical purposes only, and serves as a bridge to the SECCYD datasets. The page is not being updated.

Initiating the Study
Study Goals
Study Instruments
Study Participants
Maintaining the Study
Study Datasets
Study Publications

Funding for the SECCYD ended in 2009. Data collection on the characteristics of child care arrangements took place from 1991 to 1995, after which time the study participants were in kindergarten.

Initiating the Study

The NICHD Study of Early Child Care and Youth Development (SECCYD) is a comprehensive longitudinal study initiated by the NICHD to answer questions about the relationships between child care experiences, child care characteristics, and children's developmental outcomes.

After a thorough scientific review of the Study concepts, the NICHD selected a research team, located at universities across the United States and at the NICHD, that together has provided multiple perspectives on and interests in child care research. This team of researchers has worked cooperatively to design and implement the Study and, in 1991, enrolled a very diverse sample of children and their families at 10 locations across the United States.

Study Goals

The major goal of the NICHD Study is to examine how differences in child care experiences relate to children's social, emotional, intellectual, and language development, and to their physical growth and health. Other goals of the Study include:

  • Describing the variety, stability, and changes in children's non-maternal child care experiences over time, including the child's age when first placed in child care, and the quantity and quality of care (for instance, how old were most children when they first entered child care? How many hours did most children spend in child care each week? What types of child care arrangements did children experience? How much time did caregivers spend interacting with children?);
  • Identifying demographic and family characteristics associated with different patterns of child care use;
  • Comparing the development of children who were cared for primarily by their mothers to those who spent much of their time in non-maternal care;
  • Identifying the specific links between certain features of non-maternal child care (such as quality of care, hours each week in care, and type of care) and child development, while taking into account the important and well-documented roles of the family; in other words, identifying the exclusive link (or net effect) between child care and child development;
  • Determining whether associations between child care experiences and children's development were the same for children from different family backgrounds (such as for African American and white children, for children from rich and poor families, for children receiving more and less sensitive parenting, etc.);
  • Understanding how family characteristics (such as parents' emotional sensitivity, the quality of the home environment, parents' education, parents' psychological adjustment, and parents' attitudes and beliefs) are related to development for children who do and do not experience child care;
  • Researching the relationship of contextual influences such as the effects of early child care in relation to qualities of parents, the home environment, and school as well as social structure and demography. The outcomes of interest include: achievement of intellectual and cognitive skills, social and emotional processes, and physical health development.
  • Investigating how early functioning and experiences in concert with contextual and maturational factors in adolescence, influence social relationships, health, adjustment, and intellectual and academic development during middle adolescence; and
  • Studying intensive patterns of health and human development from infancy into middle adolescence and beyond that generates data which can be used by the broader scientific community to study a wide range of basic and applied questions.

Study Instruments

The NICHD SECCYD is characterized by a complex and detailed study design, which takes into account many variables, including characteristics of the child care and the family environment. Researchers are assessing children's development using multiple methods (e.g., trained observers, interviewers, questionnaires, and testing) and measuring many facets of children's development (e.g., social, emotional, intellectual, and language development; behavioral problems and adjustment; and physical health). This site provides listings of the instruments used, locations, and time of assignment for the assessments during:

  • Phase I (PDF - 100 KB) (birth through 3 years of age)
  • Phase II (PDF - 85.3 KB) (54 months through 1st grade)
  • Phase III (PDF - 152 KB) (2nd through 6th grades)
  • Phase IV (PDF - 100 KB) (7th through 9th grades)

Study Participants

Since 1991, the Study has followed the development of children from the time they were 1 month of age. It was conducted in four phases, based on the ages of the children when the information or data were collected. As children grew older, some families did not continue their participation in the study for different reasons (such as no longer interested, moved away, etc.), which explains why the number of children is not identical across data collection phases.

Year Children's Ages or GradeNumber of Children (and Their Families)
1991-94Phase I, ages 0-31,364 children participated in the Study
1995-99Phase II, through 1st Grade1,226 children participated in the Study
2000-04Phase III, through 6th Grade1,061 children participated in the Study
2005-2007Phase IV, through 9th Grade1,009 children participated in the Study

Maintaining the Study

Analyses for the NICHD SECCYD are conducted by a network of investigators, the NICHD Early Child Care Research Network.

Major scientific decisions about the Study are reviewed and approved by the SECCYD Steering Committee, which includes an independent chairperson, one representative from each grantee site, one representative from the data center, and one representative from the NICHD. The Steering Committee has established policies and procedures that govern the operations of the Network, including its publication procedures. Further, the NICHD also monitors the progress of the Study.

An Advisory Board of leading scholars in the field of child development and health provides additional impartial oversight. The Advisory Board meets with the Steering Committee twice a year, during regular Steering Committee meetings.

For more information on the Steering Committee and other SECCYD researchers, go to

Study Datasets

All data from Phases I, II, III, and IV of the study are analyzed by the SECCYD researchers. The datasets are made available to other researchers for further analysis. Currently, datasets for all phases of the Study are available to qualified researchers (who will be affiliates to the Study).

Those interested in becoming affiliates and using Phase I, Phase II, Phase III, or Phase IV data can apply for the data.

You can view the videotaped training session for data users that was conducted at ICPSR External Web Site Policy.

Study Publications

A searchable database of published research that uses the SECCYD data is available at External Web Site Policy.

The NICHD also published a booklet about Phase I of the SECCYD and its findings. This booklet is provided here for historical purposes only.

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