NICHD Study of Early Child Care and Youth Development: Phase I, 1991-1995 [United States] (ICPSR 21940)

Published: Nov 21, 2014

Principal Investigator(s):
United States Department of Health and Human Services. National Institutes of Health. Eunice Kennedy Shriver National Institute of Child Health and Human Development


Version V1

Alternate Title

SECCYD Phase I, 1991-1995


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.

Research Goals

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.

Data File Organization

309 data files were compiled for this study and are organized into 3 main groups:

  1. Analytical Data Sets (ADS) -- The raw data were examined and composites defined by small groups of individual principal investigators according to the demographic, family, childcare, and child outcome content of the data. The psychometric and distributional qualities of the variables along with site differences was examined. A set of variables that was psychometrically and distributionally acceptable to be used in analytic analyses was designed to test the study hypotheses. These data files comprise Parts 1-42 of the study data material.

  2. Supplemental Data Sets -- New and revised analysis variables as well as across-time mean scores and primary composites were produced as a supplement to the original Analytical Datasets. These data files comprise Parts 43-55 of the study data material.

  3. Raw Data Sets -- The raw data were made available and comprise Parts 56-309 of the study data material.

Training Workshop Recordings

A three day summer training workshop on the SECCYD was put on by the NICHD at the Inter-University Consortium for Political and Social Research in Ann Arbor, Michigan. Recordings of that workshop, coordinated with the Powerpoint slides used during presentations, are freely available to the public at the addresses described below.

Day One - Part I


  • Introductions and Participant Research Questions - James Griffin

  • Overview of Study - James Griffin

  • Schedule of Data Collection - Bonnie Knoke

  • Demographic Data - Bob Bradley

Day One - Part II


  • Family Data - Margaret Owen

  • Orientation to using the Data and Documentation - Bonnie Knoke

Day One - Part III


  • Data Documentation: Hands-on Training - Bonnie Knoke

Day One - Part IV


  • Data Orientation: Merging Data Files - Robert Corwyn

  • Child Care Data - Margaret Owen

Day One - Part V


  • Secondary Data Analysis - Peg Burchinal

Day One - Part VI


  • NICHD Funding Opportunities - James Griffin

Day Two - Part I


  • Social Data - Martha Cox

  • Peer Data - Martha Cox

  • Cognitive Data - Dan Keating

Day Two - Part II


  • School Data - Renate Houts

  • Out-of-school Data - Bob Bradley

  • Health Data - Bob Bradley

Day Two - Part III


  • Stats Presentation: Control Variables - Renate Houts

Day Three


  • Analytic Strategies - Renate Houts and Peg Burchinal

Data are available for the other phases of the NICHD STUDY OF EARLY CHILD CARE AND YOUTH DEVELOPMENT (SECCYD). See: SECCYD Phase II, 1996-1999 (ICPSR 21941), SECCYD Phase III, 2000-2004 (ICPSR 21942), SECCYD Phase IV, 2005-2008 (ICPSR 22361).


United States Department of Health and Human Services. National Institutes of Health. Eunice Kennedy Shriver National Institute of Child Health and Human Development. NICHD Study of Early Child Care and Youth Development: Phase I, 1991-1995 [United States]. Ann Arbor, MI: Inter-university Consortium for Political and Social Research [distributor], 2014-11-21.

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United States Department of Health and Human Services. National Institutes of Health. Eunice Kennedy Shriver National Institute of Child Health and Human Development (U01 HD019897)

Subject Terms

behavior problems census data child care child development children cognition demographic characteristics emotional development employment families fathers home environment infants language love marital relationship mental health mothers parent child relationship parental influence parents psychological evaluation social behavior social support toddlers

Geographic Coverage

United States New Hampshire California Kansas Virginia Arkansas Philadelphia Wisconsin Washington Pennsylvania Pittsburgh


This data collection may not be used for any purpose other than statistical reporting and analysis. Use of these data to learn the identity of any person or establishment is prohibited. To protect respondent privacy, the NICHD Study of Early Child Care and Youth Development is restricted from general dissemination. Users interested in obtaining these data must complete an Agreement for the Use of Confidential Data, specify the reasons for the request, and obtain IRB approval or notice of exemption for their research. Apply for access to these data through the ICPSR restricted data contract portal, which can be accessed via the study home page .

Time Period(s)

1991 -- 1994

Date of Collection

1991 -- 1994

Data Collection Notes

User Alert for Phase 1 Raw SAS Datasets for 24 and 36 Month Child Care Observations

The variables ID and F24HOBCY have the same label stated as "CC Observation Cycle". The label for the variable ID should be "SITE/LOC/SUBJECT ID." This effects the following files:

  • 21940\Data\Raw\SAS\
  • 21940\Data\Raw\SAS\

The variables ID and F36HOBCY have the same label stated as "CC Observation Cycle". The label for the variable ID should be "SITE/LOC/SUBJECT ID." This effects the following files:

  • 21940\Data\Raw\SAS\
  • 21940\Data\Raw\SAS\

The NICHD Study of Early Child Care and Youth Development was conducted by a network of investigators called the NICHD Early Child Care Research Network. The network was led and managed by a steering committee that included an independent chairperson, one representative from each of the grantee sites, one representative from the data center, and one representative from NICHD. The steering committee established policies and procedures that governed the operations of the network. The progress of the study was monitored by NICHD and by the steering committee with guidance from an advisory board which was nominated by the director of NICHD.

Beginning with the time of enrollment, families were scheduled for extensive periodic data collections. Data from 10 sites were collected at 5 major assessment points: 1 month (enrollment), 6 months, 15 months, 24 months, and 36 months. Month 1 enrollment data were collected in a visit to the children's homes. At six months, data were collected in the children's homes and at the children's primary childcare arrangements. At 15, 24, and 36 months, data were collected in the children's homes, childcare arrangements, and in the laboratory. Phone call data were collected every three months between major assessments.

Study Purpose

To examine the influence of variations in early childcare histories on the psychological development of infants and toddlers from a variety of family backgrounds.

Study Design

The SECCYD is a multi-site, prospective, longitudinal study of the experiences of 1,364 children and their families. Respondents were sampled from a catchment of some 6,189 children. Children's development was assessed via trained observers, interviewers, questionnaires, and direct testing. Measures were taken on many facets of children's development, such as social, emotional, intellectual, as well as language development, behavioral problems and adjustment, and physical health.


Participants were selected in accordance with a conditionally random sampling plan, designed to ensure that the recruited families (a) included mothers who planned to work or to go to school full-time (60 percent) or part-time (20 percent) in the child's first year, as well as some who planned to stay at home with the child (20 percent), and (b) reflected the demographic diversity (economic, educational, and ethnic) of the sites. Both two-parent and single-parent families were included. The major exclusionary criteria used were (a) mothers younger than 18 years of age at the time of the child's birth, (b) families who did not anticipate remaining in the catchment area for at least 3 years, (c) children with obvious disabilities at birth or who remained in the hospital more than 7 days postpartum, and (d) mothers not sufficiently conversant in English.

Analyses have indicated that the data do reflect the natural distributions of these factors in the catchment. Therefore, inferences from this data can be made directly to the catchment without back-weighting for the sampling factors. In addition, analyses have shown that the NICHD data reflect to large degree the natural distributions of certain factors measured in the 1990 Census data. However, the NICHD data are not representative in the statistical sense, and therefore inference to the nation as a whole is not possible. Comparisons to other databases, national or otherwise, should be made with extreme caution.


Full-term, healthy newborns of mothers giving birth in hospitals at 10 locations throughout the United States during designated 24-hour periods between January and November 1991.

Unit(s) of Observation


Data Type(s)

clinical data, observational data, survey data

Mode of Data Collection

computer-assisted personal interview (CAPI), computer-assisted self interview (CASI), computer-assisted telephone interview (CATI), coded on-site observation, cognitive assessment test, face-to-face interview, mail questionnaire, paper and pencil interview (PAPI), self-enumerated questionnaire, on-site questionnaire, telephone interview

Description of Variables

The 42 Analytical Data Sets (ADS) contain composite variables created, from the raw data by Quantitative Systems Laboratory (QSL) at Vanderbilt University, to be psychometrically and distributionally acceptable for analytical analysis of the study hypotheses.

The 13 Supplemental Data Sets were produced by Research Triangle Institute (RTI) and contain new and revised analysis variables, across-time mean scores, and primary composites.

The 254 Raw Data Sets contain the direct item-level data collected per instrument.

Presence of Common Scales

Bayley Scale of Infant Development

Adaptive Social Behavior Inventor -- Child

Child Behavior Checklist -- Child

MacArthur Communicative Inventory

Adaptive Social Behavior Inventory -- Mother

Child Behavior Checklist -- Mother

Peabody Picture Vocabulary Test

Reynell Developmental Language

Bracken Basic Concept Scale

Original Release Date


Version Date


Version History

2010-01-26 User Agreement updated.

2009-10-29 ICPSR data undergo a confidentiality review and are altered when necessary to limit the risk of disclosure. ICPSR also routinely creates ready-to-go data files along with setups in the major statistical software formats as well as standard codebooks to accompany the data. In addition to these procedures, ICPSR performed the following processing steps for this data collection:

  • Performed recodes and/or calculated derived variables.
  • Checked for undocumented or out-of-range codes.

2014-11-21 releasing additional documentation - Measures Chart

2014-10-21 Releasing questionnaires and user guide.

2010-01-08 Various data and documentation was resupplied. Other files were processed differently or had errors fixed.


  • The public-use data files in this collection are available for access by the general public. Access does not require affiliation with an ICPSR member institution.

  • One or more files in this data collection have special restrictions. Restricted data files are not available for direct download from the website; click on the Restricted Data button to learn more.

DSDR logo

This study was originally processed, archived, and disseminated by Data Sharing for Demographic Research (DSDR), a project funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD).