National Longitudinal Surveys
Bureau of Labor Statistics > National Longitudinal Surveys > Methods > NLSY79Child / Young Adult User Guides

NLS79 Child and Young Adult User Guides and Documentations

Using and Understanding the Data

Information on survey instruments, variable types, the interviewing process, item nonresponse, sample weights and design effects, data documentation, and how to access the data are available below.  To learn more about the cohort, please see the NLSY79 Child and Young Adult Data Overview

Survey Instruments

Multiple field instruments, in both paper and computer-administered format, have been used to collect information from and about the NLSY79 children. These instruments are used to assess the children and to elicit reports about their health, aptitudes, achievement, attitudes, relationships and behaviors. A brief description of these instruments is presented below. For more detailed information, go to the following links: Child Survey Instrument Structure & Content and Young Adult Survey Instrument Structure & Content.  Users are urged to examine the NLSY79 Child and Young Adult data collection instruments and relevant main NLSY79 Youth questionnaires in conjunction with the other documentation that accompanies the data files. Child and Young Adult questionnaires are available in PDF or HTML form on the Child/YA Questionnaires page; main youth questionnaires are available on the NLSY79 Questionnaires page. More detailed discussions of the content of each questionnaire and the mode of administration used in the current survey are provided the Interview Methods section. Information about linking the data to the questionnaires is provided in the Question Names & Reference Numbers section of this guide. View Survey Instruments.

Question Names and Reference Numbers

Each NLSY79 child variable has a "question name" that helps to identify it in the data file and permits users to locate the original question in the questionnaire. Variables in the NLSY79 child data are generally named according to the source from which they are derived. Items from the Child, Mother, and Child Self-Administered supplements have question names linked to the location in the instrument.  For more information, click on the following links: Child Question Naming ConventionsYoung Adult Question & Variable Names, and Child & Young Adult Reference Numbers.  View Question Names and Reference Numbers

Types of Variables

The NLSY79 Child and Young Adult data release contains comprehensive information from the 1986 through the current survey round. The file also contains child-specific information from the mother's main Youth interviews. Certain variables are derived from the mother's longitudinal record while other data items represent the questions administered during the Child and Young Adult interviews and the responses from each child assessment. Finally, there is an extensive set of created variables on the file, based on the assessment and interview data.

Detailed information on the types of data available for the NLSY79 Children and Young Adults can be found by examining the field instruments and by searching the database indices. Instructions on how to search the database can be found in the Investigator User's Guide. Researchers who are interested in items based on data from the mother's record are encouraged to access copies of the main Youth questionnaires and to review the NLSY79 main Youth documentation. View the NLSY79 Data Overview to learn more. Information on how to link child and mother data can be found primarily in the section on Linking Children, Young Adults, and Mothers.  View Types of Variables.

Sample Weights

Appropriate sample weights are available in each year to adjust the un-weighted sample cases for the minority oversamples and year-to-year sample attrition. The sample weights for younger children and young adults adjust the un-weighted data for sample attrition of mothers and their children since the first survey round (1979) and the sample reduction due to the loss of the military and economically disadvantaged white oversample.  They are also adjust the sample for the over-representation of black and Hispanic youth.  If users need longitudinal weights for multiple survey years or for a specific set of respondent ids, they can create custom weights by going to the NLSY79 Child and Young Adults Custom Weighting page.  View Sample Weights.

Noninterviews and Item Nonresponse

Missing values are indicated in the data and on the codebook page for each individual question. Following general NLS convention, a response of "don't know" to an individual question is coded "-2," a refusal to answer an individual question is coded "-1," and an invalid skip is coded "-3." (Invalid skip means that the respondent should have answered the question but didn't; this was more common in the paper-and-pencil interviews when the respondent or interviewer might make an error following the skip pattern on a paper instrument. The incidence of invalid skips has been significantly reduced in the computer-assisted interviews.) In the NLSY79 Child and Young Adult, noninterviews and valid skips (when a respondent was purposely not eligible for a question) have been collapsed into a "-7." Thus, users must know how to distinguish between noninterviews and valid skips for some types of research. View Noninterviews and Item Nonresponse.

Interview Remarks

At the conclusion of each child interview, interviewers complete a summary evaluation of the overall interview and a series of "testing conditions" items.  Information about interviewer remarks in the child supplement and the young adults are available online. 

The Child/Young Adult data files contain many constructed variables drawn from multiple sources, including both cross-sectional and longitudinal information in both the child and mother records. Users of the Child/Young Adult data who wish to construct variables not found in the Child/Young Adult files may access the mothers' records in the main Youth files in order to obtain the necessary inputs. A useful variable for linking the mother's longitudinal record to the child is C00052.00, which defines the first survey year (of the mother) following the child's date of birth. The question name for this variable is FSTYRAFT. (NOTE: Children born prior to the 1979 survey date are assigned 1979 as their first post-birth survey point.) 

NLS Tutorial: Linking Mothers and Children gives detailed instructions on how to link a data file of young adult children extracted from the Child/Young Adult database with a file from the main Youth file for mothers. This example with step-by-step instructions will assist users still uncertain about the linking process.  View Linking Children, Young Adults, and Mothers.

NLSYCA Documentation

In addition to this online User's Guide, a number of documentation items are provided to help users understand the Child and Young Adult data.  Users can review codebook pages for variables of interest through NLS Investigator, and extracts of variables include a custom codebook file containing codebook pages for all variables in the extract.  Additional assistance is available through NLS User Services.  View NLSYCA Documentation.

Intercohort and Cross Generational Research

These sections outline some research topics for which the NLSY79 Child and Young Adult data are particularly appropriate. Specific topics are not explored in depth but instead are presented as examples of a range of subjects that can be investigated. The focus here is on ways in which data from the main NLSY79 mothers, the younger children, and the young adults can be linked, allowing researchers to carry out not only within but also cross-generational research. Specific procedures for accessing and linking the various data files are discussed in Linking Children, Young Adults, and Mothers.  See Life Cycle Profiles for the NLSY79 Children and Possible Research Agendas for more information.  View Intercohort and Cross Generational Research.

Pooling Sample Sizes

The panel dimension of the NLSY79 data collection permits one to cumulate sample cases for children at specified ages across survey points, thus attaining rather substantial sample sizes for those ages. Pooling in this manner also can greatly enhance the heterogeneity of the sample for specific research topics. The trade-off to this methodology is that the ability to follow a particular age cohort across survey years becomes somewhat limited, although it is still doable for selected research topics. This table highlights potential sample sizes using this approach.  View Pooling Sample Sizes.

 

Last Modified Date: April 24, 2020