Area of interest: description of the main research areas of the variable, such as health or employment.
Codebook: text that describes each survey variable, including its frequency of responses, range of values, and any special notes about the variable.
Created variable: a variable created by survey staff that generally combines a series of respondent questions or is from an outside source.
Event-history variables: includes two specific types of variables created by survey staff. The first describes the status during a given timeframe and is presented in arrays that are either weekly (for example, employment status during each week) or monthly (for example, participation in certain government assistance programs during each month). The second type provides dates of various events, such as job start and stop dates or year the respondent was in a particular grade of school.
PUBID: unique respondent public identification number that applies to all arounds of an NLS data set. When data are extracted, each respondent record is an observation. If you want to merge multiple data sets from a NLS cohort, this is done using the PUBID. This variable is pre-selected for you in the NLS Investigator.
Question name (QNAME): code assigned to identify each question, which gives the location of the variable in the questionnaire or identifies it as a created variable. When possible, question names remain the same for the same question across survey years.
Reference number (RNUM): letter and number combination uniquely assigned to each variable.
Roster variables: variables created within the survey instrument that list certain items, such as employers or household members and their characteristics.
Survey year: identifies survey waves, and is the year in which the survey period began for the particular interview round.
Tag: in the Investigator, the term means to select a variable by clicking on a checkbox.
Tagset: in the Investigator, a set of user-selected variables identified by Reference Number (RNUM) or Question Name (QNAME) with survey year. The tagset is then used to extract an NLS data set.
Universe: sample of respondents that received a particular survey question.
Variable Preference Level: allows users to decide what type of variables to display in the search results.
  1. Primary variables: the most important and the most commonly used, generally include all created and event-history variables, all roster variables, and respondents’ responses to survey questions that are not superseded by better information in a roster or created variable.
  2. Secondary variables: questions asked in the interview that are superseded by created or roster variables. While these questions might be useful for very detailed research about a narrow topic, they won’t be needed by most researchers.
  3. Tertiary variables: generally machine check items. These are included in the data to enable researchers to follow the flow of the interview, but in most cases they should not be used as input variables in research. They are displayed only when the "show all" Variable Preference Level is selected.
Variable title: description of a particular variable.