Interview Dates. During the NLSY79 survey rounds in which multiple Child instruments were used, the child instruments were not always fielded on a single date. For example, from 1986-2004, interviewers assigned to assess two or more children in a single family might ask the mother to complete one or more Mother Supplements (one MS for each child) on the first visit to the home. On that first visit the interviewer might complete one Child Supplement (CS) and one Child Self-Administered Supplement (CSAS), scheduling the remaining Child Supplements for all children until the next visit on a subsequent day. Even when the CSAS was folded into the Child Supplement in 2006, it was possible for a child to complete most of the CS (including the assessments) on one date, and then complete the CSAS section later. Starting in 2006, when the Mother Supplement was first integrated into the mothers' main interview, the date of the Mother supplement became the same as the mother's date of interview (DOI), since the mother's main Youth interview was generally completed in one session.
Fielding Periods. Historically, the field period of the NLSY79 Child and Young Adult data collection generally coincides with the main Youth. However, starting in 2002, main Youth and Young Adult telephone interviewing began substantially prior to the younger child interviews. While this fielding strategy had a positive impact on overall completion rates, it potentially widened the gap between the mother's interview and the assessments administered to her children later in the year. Fielding typically occurs over a period of about six months from late May through November or later. In some survey rounds a small number of cases were actually completed in the calendar year following the survey year.
As indicated in Table 1, child fielding has generally occurred over periods of approximately 6-9 months in each survey round; the young adult field period may last somewhat longer. Until 2004, data collection was completed within the calendar year of the particular survey round. In 2004, child interviews were conducted June-December, with 15 cases completed in January-February 2005. In R22-2006, child interviews were conducted March-December, with 33 cases completed in January-February 2007. In R23-2008, nearly all child interviews were conducted April-December 2008, with 19 cases completed in January-February of 2009. In R24-2010, nearly all child interviews were conducted March-December 2010, with an additional 2 cases completed in January of 2011. In R25-2012, child interviews were conducted November 2012-August 2013, with more than half the cases completed in 2013.
Table 1. NLSY79 Child and Young Adult Surveys: Fielding Periods
Child fielding period
Young Adult fielding period
February 1986 - July 1986
June 1988 - December 1988
June 1990 - December 1990
May 1992 - December 1992
June 1994 - December 1994
June 1994 - December 1994
April 1996 - November 1996
May 1996 - October 1996
March 1998 - October 1998
March 1998 - September 1998
May 2000 - January 2001
March 2000 - January 2001
May 2002 - November 2002
January 2002 - December 2002
June 2004 - February 2005
January 2004 - February 2005
May 2006 - March 2007
January 2006 - March 2007
April 2008 - February 2009
January 2008 - March 2009
March 2010 - January 2011
December 2009 - January 2011
November 2012 - August 2013
August 2012 - September 2013
Information on fielding (interview) dates specific to each survey round can be found in the year-specific CHILD SUPPLEMENT, CHILD SELF-ADMINISTERED SUPPLEMENT and MOTHER SUPPLEMENT areas of interest.
In 1986 and 2006-present the titles for date of interview are as follows:
CHILD SUPPLEMENT DATE OF INTERVIEW MOTHER SUPPLEMENT DATE OF INTERVIEW
In all other years these items are described with the following titles:
CHILD SUPPLEMENT INTERVIEW DATE MOTHER SUPPLEMENT INTERVIEW DATE
Changes in the Child Assessments
Over time there have been changes in the administration of various assessments in the Child surveys. Details on changes in the content, administration, or scoring of particular assessments are discussed in the appropriate assessment-specific sections of this users guide (see "The Child Assessments: Introduction" for an overview). Two assessments, Memory for Location and Body Parts, were administered in 1986 and 1988, but have since been deleted from the data collection effort due to funding constraints. However, the 1986 and 1988 individual items and scores for these two assessments remain in the data file and are available to users.
Not all assessments are fielded in each child survey year. In some instances, assessments are administered only to children for whom no valid score has been obtained during a previous survey. In 1988 a procedure was introduced by which children ages 10 or 11 were designated to complete any assessment for which they were age-eligible in order to establish a representative index group for future analyses. Starting in 1996, the Self-Perception Profile (What I Am Like) is only administered to children ages 12 and over. The McCarthy Verbal Memory Subscale was administered for the final time in 1994. In 2004 very young children were not administered assessments, which means that scores are not available for Motor and Social Development in 2004.
Young Adult Survey
By 1994, substantial numbers of children of NLSY79 mothers had reached at least mid-adolescence. Because of the enormous potential for further research possibilities with the NLSY79 cohort and their offspring, the decision was made to separate these older children into a third NLSY79 component: the Young Adults. Beginning in 1994, NLSY79 children ages 15 and older by the end of a survey year were no longer given cognitive and other assessments, but instead received a more standard Computer Assisted Personal Interview (CAPI) survey. This Young Adult CAPI questionnaire focuses on the transition to adulthood, with detailed questions on education, employment, training, health, family experiences, attitudes, interactions with family members, substance use, sexual activity, non-normative activities, computer use, health problems, and pro-social behaviors. Many questions in the Young Adult survey parallel those asked of their mothers over the years, particularly when their mothers had been at comparable life cycle points. However, the Young Adult survey contains more in-depth data in certain areas such as sexual activity, drug use, schooling activities, attitudes, and marriage and cohabitation histories. The primary interview mode for the 1994 through 1998 survey rounds was in-person interviewing. Beginning with the 2000 survey round the primary mode has shifted to telephone interviewing.
Older children who are defined as eligible for the Young Adult survey for a given round are said to be "fielded" in that survey year. Not all older children represented in the child file are eligible to be fielded as Young Adults, for a variety of reasons. Whereas the child file includes all children known to have been born to NLSY79 mothers, the older children of mothers in the no longer interviewed military and poor white oversamples are ineligible to be interviewed as Young Adults. Additionally, children who have no child interviews or only one assessment point from very early in the child study, such as 1986 or 1988, and/or who have not been co-resident with their mothers at least part time are usually not fielded in the Young Adult sample. Generally speaking, we field older children who have either been assessed or interviewed in recent rounds, or who are currently or were typically living with their mother either full or part time during at least part of their childhood. Of course, not all of the children we field as Young Adults get interviewed. Mothers may refuse to allow younger Young Adults (under age 18) to be interviewed, the Young Adults themselves may refuse, or we may fail to locate them.
In 1994 and 1996, the Young Adult sample included all children who were age 15 and over by December 31 of that year and who met the other selection criteria. Due to budgetary constraints, the Young Adult sample in 1998 was limited to youth through age 20 as of the interview date. With additional funding through a grant from NICHD, in 2000-2008 the sample again included Young Adults ages 21 and older, as well as those ages 15 to 20. In 2000 only, around 40% of the black and Hispanic oversample cases between the ages of 15 and 20 were not fielded for budgetary reasons. These Young Adults were once again eligible to be interviewed in 2002. Beginning in 2010, Young Adult respondents over the age of 30 have been moved to a four-year interview cycle. The interviewed sample is selected by age as of December 31 of the survey year, so that approximately half of the older young adults are eligible each round. Beginning in 2010, young adults age 31-32, 35-36, 39-40, 43-44, etc, as of December 31 of the survey year are not fielded.