The "National Longitudinal Study (NLS) of the High School Class of 1972: Base Year (1972) through Fourth Follow-up (1979)" machine-readable data file (MRDF) is a single merged file of student responses to the original interviews or tests in 1972 and the mail follow-up surveys of 1973, 1974, 1976, and 1979. The 1972 data were gathered by the Educational Testing Service (ETS). The 1973-1979 follow-up data were gathered by the Research Triangle Institute (RTI). The purpose of NLS is to follow the educational and occupational activities, plans, aspirations, and attitudes of a national sample of young adults in the United States after they leave high school and enter early adulthood. The NLS-72 survey represented a total twelfth-grade population of three million seniors in more than 17,000 high schools in the spring of 1972. The NLS-72 stratified, two-stage probability sample included over 22,000 students enrolled in over 1,300 public and private high schools in all 50 states and the District of Columbia. Students from schools for the physically and mentally handicapped and schools for the legally-confined were excluded. More than 3,500 variables were captured for each student, including: ability, socioeconomic status, home background, community environment, ethnicity, current activity at the time of the survey, educational attainment, school experience, school performance, work status, work performance, work satisfaction, goal orientation, mental status, financial status, military experience, etc. Follow-up surveys added variables such as: college education, college admissions test scores, courses of study, degrees received, earnings per week, grade point average, jobs held, life goals, organization activities, political participation, school expenses, spouse's earnings, spouse's education, tuition and fees paid, work experience. The merged file for 1972-1979 contains a total of 22,652 records, each with a logical record length of 11,475 characters. POPULATION: High school seniors, 1972 (3,000,000); high schools (>17,000). TYPE OF SURVEY: National Survey; Longitudinal Survey; Follow-up Survey. RESPONDENTS: High school seniors participating in NLS-72. SAMPLE: High school seniors, 1972 (23,451); high schools (>1,300). FREQUENCY: Periodic. RESPONSE RATE: High school seniors, 1972 (22,652=96.5%); high schools (1,300). YEAR OF FIRST DATA: 1972. (CDM/WTB)