Important information: Using age variables

1. There are three variables that provide the youth's age in years: CV_AGE_INT_DATE, KEY!AGE, and SYMBOL!KEY!AGE. Researchers should use CV_AGE_INT_DATE for the most accurate information. Background information on the age variables: The KEY!AGE variable is a symbol generated during the administration of the Screener, Household Roster, and Nonresident Roster Questionnaire in round 1. Thus, it initially represented the respondent's age at the screener date. During the youth interview, respondents had an opportunity to correct their age if it had changed since the administration of the screener or was reported incorrectly by the household informant. If a new age was provided, the KEY!AGE variable was updated. However, approximately 400 respondents either had a birthday between the screener date and the youth interview date or had incorrect information collected during the screener but did not correct their age information during the interview. SYMBOL!KEY!AGE (R25162.) is a variable generated during rounds 2 and up and is necessary because the survey program uses it during the interview. The ages in SYMBOL!KEY!AGE and CV_AGE_INT_DATE vary slightly in some rounds due to computer programming variations. This is why researchers are urged to use the created age at interview date variable, CV_AGE_INT_DATE, which presents the youth's age at the time the survey is administered. This latter variable is constructed using birth date and interview date information collected during the interview.
2. Because some respondents were first interviewed during the refielding period in March through May 1998, there are respondents in the sample who had already turned 18 by their round 1 interview date. These respondents were still eligible for the sample because they were age 16 or younger as of December 31, 1996. See Interview Methods for more information.
3. The youth respondent and the responding parent both had an opportunity to verify or correct the respondent's age as reported in the Screener, Household Roster, and Nonresident Roster Questionnaire in round 1. However, if the youth and parent did not provide the same age and/or date of birth, no attempt was made to correct this discrepancy. Users should make decisions about these cases on an individual basis. The created variables for age are based on the youth data.