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National Longitudinal Survey of Youth 1979 (NLSY79)

NLSY79 Appendix 17: Interviewer Characteristics Data

Interviewer characteristics data and data review

Many researchers are interested in knowing if or how much interviewers affect respondents' answers. To enable researchers to investigate these questions, NLSY79 data releases since 1988 have contained information on interviewers' characteristics.

Constructing the Interviewer Characteristics ID and Interview Attribute variables

The key variable, which links the NLSY data set with the interviewer characteristics data set, is INTCHARS_INT_ID. This ID variable is often similar but not necessarily identical to the Interviewer ID variable, which is entered in the questionnaire and can be found on the NLSY79 public use data set for many years. INTCHARS_INT_ID is a constructed longitudinal variable that allows identification of cases interviewed by the same person over time. While some interviewers were assigned multiple IDs during their tenure, it was possible to successfully connect the records of most interviewers through their active years.

Each round, new IDs are assigned to new interviewers who do not have a longitudinal ID. From 1979-2000, information on the characteristics of NLSY79 interviewers primarily comes from NORC's interviewer personnel files. Data from the 2002-present surveys come from forms filled in by interviewers during their NLSY79 training program. Collecting this information directly from interviewers before each round ensures that the interviewer characteristics data is up to date at the start of data collection. Users should note that not all interviewers have filled out this demographic survey in the survey years that they worked. 

The variables that document Interviewer-specific traits are found in the “Interviewer Characteristics” Area of Interest:

  • INTCHARS_YRSINTR: Interviewer Count (available 1979 - 2014)
    • This counts the number of years the interviewer has interviewed the respondent, including the current survey year. Note that as telephone interviews become more prevalent, the number of first-time interviews expands considerably, as most interviewers are not assigned to specific cases year after year.
  • INTCHARS_RACE: Interviewer Race (available all years)
    • 1 = WHITE
    • 2 = BLACK
    • 3 = HISPANIC
    • 4 = ASIAN
    • 5 = AMERICAN INDIAN
    • 6 = MULTICULTURAL (available beginning in 2016)
    • 7 = OTHER (available beginning in 2018)
    • -3 = missing
  • INTCHARS_SEX: Interviewer Sex (available all years)
    • 1 = MALE
    • 2 = FEMALE
    • -3 = missing
  • INTCHARS_AGE: Interviewer Age (available 1979-2014)
    • Age of the interviewer in the interview year, calculated as ([survey year]-[interviewer’s year of birth])
    • -3 = missing
  • INTCHARS_EDUCATION: Interviewer Education (available all years)
    • 1 = Grade 0-8
    • 2 = Grade 9-11
    • 3 = High School Graduate
    • 4 = Vocational degree
    • 5 = Some College
    • 6 = College Graduate
    • 7 = Graduate School
    • 8 = Masters Degree
    • 9 = Professional Degree
    • 0 = Other
  • INTCHARS_FI_EXP: Interviewer Experience (available 2016-current round)
    • Interviewer experience in years, from < 1 – 17+ years
    • -3 = missing
  • INTCHARS_HISPANIC: Interviewer of Hispanic Ethnicity (available 2016-current round)
    • 0 = Non-Hispanic
    • 1 = Hispanic
    • -3 = missing
  • INTCHARS_DEM: Interviewer Demographic Data Released (available 2018-current round)
    • Indicates if the interviewer provided permission to release demographic data.
    • 1 = Yes
    • 0 = No
  • INTCHARS_HPC: Hours Per Case (available 2018-current round)
    • Interviewer average hours per case as percentage of project hours per case in the first 8 weeks of fielding.
    • -3 = missing
  • INTCHARS_POS: Interviewer Position (available 2018-current round)
    • 1 = Field Interviewer
    • 2 = Field Manager
  • INTCHARS_SPANISH_SPEAK: Interviewer Position (available 2018-current round)
    • 1 = Yes
    • 2 = No
  • INTCHARS_OCC: Interviewer Occupation (available 2018-current round)
    Open-ended response that asks interviewers to describe their previous or other current occupation(s) besides interviewing. These responses are coded in the following occupation categories:
    • 0 = Not employed
    • 1 = Interviewer
    • 2 = Teaching
    • 3 = Sales and customer service
    • 4 = Administrative assistant, secretarial, clerical & accounts
    • 5 = Medical/health care administrator
    • 6 = Nursing, social work, mental health practitioner, pharmacists & medical    assistants
    • 7 = Insurance, real estate & travel agent
    • 8 = Small business owner
    • 9 = Self-employed & other occupations
    • 10 = Other (professional)
    • 11 = Manager, Supervisor, Director
    • 12 = Social worker, Counselor, Non-profit
    • 13 = Government

Other variables found in the “Survey Methodology” Area of Interest document the interviewers time with the project.

  • R##_FI_START~[M/Y]: Interviewer Start Date (available 2018-current round)
    Month/year interviewer started working on current NLSY79 round.
  • R##_FI_END~[M/Y]: Interviewer End Date (available 2018-current round)
    Date Interviewer stopped working on current NLSY79 round.
  • R##_FI_FIRST_DAY: Interviewer First Work Day (available 2018- current round)
    First day of field period that interviewer worked on current NLSY79 round.
  • R##_FI_LAST_DAY: Interviewer Last Work Day (available 2018- current round)
    Last day of field period that interviewer worked on current NLSY79 round.

Constructing the Interview Characteristics variables

Variables that summarize interactions with respondents, survey characteristics, and field activities are found in the “Survey Methodology” Area of Interest.

A portion of interviews each survey round are reviewed by a human coder to evaluate interview quality as part of the NLSY computer audio recorded interview (CARI) monitoring process and select variables summarize the review. During the CARI process, portions of recorded interviews are reviewed for data quality to provide feedback to the interviewer. The audio review outcome variable provides the results of these reviews at an individual case level. Note that not all cases are reviewed, so many interviews will not have an audio review outcome.

  • R##_REVIEW_OUTCOME: Audio Review Outcome (available 2016-current round)
    Results of review of audio recordings for this interview for data quality assurance.
    • 1 = High quality
    • 2 = Case had minor quality issues
    • 3 = Not reviewed

Interviewers are also categorized into quality tiers based on the aggregate results of all CARI reviews of their cases. The FI quality tier variable records this information, where cases are linked to interviewers using the process described above for interviewer characteristics variables. 

  • R##_FI_QUALITY_TIER: FI Quality Tier (available 2016-current round)
    Indicates the final quality assessment of the field interviewer completing the interview, not necessarily quality of the specific interview.
    • 1 = Confirmed High Quality
    • 2 = Partially Confirmed High Quality
    • 3 = Some Issues, Quality Acceptable
    • 4 = Significant Issues

Variables for locating, case disposition, attempts, outreach, and case refusals are constructed from NORC’s case management system that records all contacts with a case. Starting in 2018, an outreach attempts variable was also included to distinguish between all effort spent on a case and outreach that represented a direct attempt to contact a case. These outreach attempts are a subset of the total attempts variable.

  • R##_LOCATING: Case to Locating (available 2016-current round)
    Indicates if the case was every assigned to locating during the data collection round.
    • 0 = Not assigned to locating
    • 1 = Assigned to locating
  • R##_DISP_DATE: Disposition Date (available 2016-current round)
    Date case disposition assigned.
  • R##_FIRST_ATTEMPT: Field Day 1st Attempt (available 2016-current round)
    Sequential day of the field period when first contact was made with case.
  • R##_LAST_ATTEMPT: Field Day Last Attempt (available 2016-current round)
    Sequential day of the field period when last attempt at contact with case was made.
  • R##_PEOPLE_WORKING: People Working (available 2018- current round)
    Total number of interviewers that worked on the case.
  • R##_OUTREACH_ATTEMPTS: Interviewer Outreach Attempts (available 2018- current round)
    The number of times a project staff member attempted to reach the case. This number includes only attempts to reach the case and other individuals who might be helpful in completing the interview (including locating for outreach) and omits comments and case review notes by interviewers.
  • R##_IN_PERSON_OUTREACH: In-Person Outreach (available 2016-current round)
    • 0 = No in-person outreach made
    • 1 = In-person outreach made
  • R##_REFUSED: R Ever Refused Interview (available 2016-current round)
    Indicates if the case ever refused to participate during various contact attempts in the round. Interview may eventually have been completed.
    • 1 = R refused at least once to participate in interview
    • 0 = R never refused to participate in interview
  • R##_ATTEMPTS: Number of Total Attempts Across Round (available 2018-current round)
    Number of times project staff tried to contact case (all types of contact)
  • R##_ATTEMPTS_EB: Interviewer Attempts Early Bird (available 2016-current round)
    Number of contact attempts during Early Bird phase (first 4 weeks after case released for interview).
  • R##_ATTEMPTS_OUTBOUND: Interviewer Attempts Outbound (available 2016-2020)
    Number of contact attempts after Early Bird phase, during outbound dialing phase.
  • R##_ATTEMPTS_CASE_MANAGED: Interviewer Attempts Case Managed (available 2016-current round)
    Number of contact attempts during case-managed phase of field period, after outbound dialing phase.
  • R##_EB_COMPLETE: EB Complete (available 2016 only)
    • 1 = Yes
    • 0 = No

A replicate group variable is included starting in 2016, which is assigned based on the likelihood that a case will complete that round. The definitions of these groups can vary by round, but in all rounds are constructed based on the likelihood that a respondent will complete, which is then used in targeting outreach to respondents throughout the round.

  • R##_REPGROUP: Replicate Group (available 2016-current round)
    • 1 = High response probability
    • 2 = Middle response probability
    • 3 = Low response probability

Variables on eligibility for incentives are constructed based on eligibility rules for a given round. All variables measuring the receipt of incentives are constructed from records of incentives that were paid to cases following completion of the interview. 

  • R##_INCENTIVE_AMT: Incentives (available 2016-current round)
    Total incentive amount paid, including Early Bird, Missed Interview and Final Push Incentives
  • R##_EB_BONUS_AMOUNT: Early Bird Bonus Amount (available 2018- current round)
    • 0 = Did not receive
    • 30 = Received
  • R##_EB_ADJACENT: Early Bird Adjacent (available 2018-current round)
    Because of operational issues (e.g., weather, mailing delays, government shutdowns, etc.), the early bird window can be expanded for some cases. This flag indicates cases that received these “adjacent” early bird payments outside of the traditional early bird window.
    • 0 = Did not receive
    • 30 = Received
  • R##_MISSED_NIR_BONUS: Missed NIR Bonus (available 2018- current round)
    • 1 = Not eligible
    • 2 = 1 round missed
    • 3 = 2 rounds missed
    • 4 = 3 or more rounds missed
  • R##_MISSED_NIR_BONUS_AMOUNT: Missed NIR Bonus Amount (available 2018- current round)
    • 0 = Completed last round
    • 20 = Missed last round
    • 30 = Missed two rounds
    • 40 = Missed three or more rounds
  • R##_ENHANCED_FINAL_PUSH: Enhanced Final Push (available 2018- current round)
    • 1 = Eligible
    • 2 = Ineligible, does not meet criteria for enhanced final push eligibility
    • 3 = Ineligible, in demographic group offered enhanced final push, but completed prior to start of enhanced final push period
  • R##_ENHANCED_FINAL_PUSH_AMOUNT: Enhanced Final Push Amount (available 2018- current round)
    • 0 = Did not receive
    • 20 = Received
  • R##_FINAL_PUSH: Final Push (available 2018- current round)
    • 1 = Eligible
    • 2 = Ineligible
  • R##_FINAL_PUSH_AMOUNT: Final Push Amount (available 2018- current round)
    • 0 = Did not receive
    • 30 = Received

In Round 29, an experiment was run on the final push incentive that randomly assigned cases into one of two groups. The first group received final push around the traditional time, whereas the second group received final push 6 weeks later. The R29_FINAL_PUSH_EXPERIMENT and R29_FINAL_PUSH_EXPERIMENT_COMPLETION variables measure the eligibility and outcome of this experiment.

  • R29_FINAL_PUSH_EXPERIMENT: R29 Final Push Experiment (available 2020 only)
    • 1 = Eligible for Phase I (Treatment Group)
    • 2 = Eligible for Phase II (Control Group)
    • 3 = Ineligible because completed/NIR prior to start of experiment
  • R29_FINAL_PUSH_EXPERIMENT_COMPLETION: R29 Final Push Experiment Completion (available 2020 only)
    • 1 = Completed during Phase I
    • 2 = Completed during Phase II
    • 3 = Completed/NIR prior to start of experiment

A small set of variables also summarizes the number of responses and the percentage of invalid responses.

  • R##_RESPONSES: R Responses (available 2016-current round)
    Total Number of Responses Provided by Case
  • R##_PCT_DK: Percent Don’t Know Responses Current Round (available 2004-current round)
    Actual percent DK responses.
  • R##_PCT_REF: Percent Refusal Responses Current Round (available 2004-current round)
    Actual percent REF responses.

Beginning in 2018, interviewer characteristics were included for all respondents who were fielded, but not interviewed, as well as interviewed respondents. For non-interviewed respondents, characteristics for the most recent interviewer assigned to the case are contained in the data where available. 

Table 1. Interviewers identified in NORC database by survey year
Year Number of Respondents Interviewed Number of Interviewers Matched Percentage Not Matched
1979 12686 9838 22.4%
1980 12141 11200 7.8%
1981 12195 11850 2.8%
1982 12123 11736 3.2%
1983 12221 11980 2.0%
1984 12069 11585 4.0%
1985 10894 10850 0.4%
1986 10655 10560 1.0%
1987 10485 10485 0.0%
1988 10465 10386 10.2%
1989 10605 9906 6.6%
1990 10436 9321 10.7%
1991 9018 8933 1.0%
1992 9016 8947 0.3%
1993 9011 8933 1.0%
1994 8891 8701 2.1%
1996 8636 8050 6.8%
1998 8399 8302 1.2%
2000 8033 7814 2.7%
2002 7726 7723 0.0%
2004 7661 6851 10.6%
2006 7654 7328 4.3%
2008 7757 7742 0.1%
2010 7565 7559 0.0%
2012 7301 7293 0.1%
2014 7071 6977 1.3%
2016 6913 6913 0.0%
2018 6878 6878 0.0%
2020 6535 6535 0.0%
2022 6413 6413 0.0%