High School and Beyond is a national longitudinal study of the cohorts of 1980 seniors and sophomores in the United States, intended to provide information on these students through early adulthood. This base year student file, a machine-readable data file (MDRF), is the first information available from the study. It includes information on 58,270 students from 1,015 public and private schools. The senior questionnaire contained 121 questions; the sophomore questionnaire contained 114 questions. The file includes information on personal background; education; work experiences; postsecondary plans and aspirations; school activities; attitudes; and verbal and non-verbal cognitive test scores from a nine-part battery for seniors and a seven-part battery for sophomores. The tape includes four parts: (1) student data file; (2) machine readable codebook; (3) Statistical Analysis System control card file; and (4) Statistical Package for the Social Sciences control card file. The codebook is also available as a bound volume. POPULATION: High Schools (24,725); High School Sophomores (3,779,288); High School Seniors (3,040,000). TYPE OF SURVEY: National Survey; Sample Survey; Longitudinal Survey. SAMPLE: High Schools (1,122); High School Sophomores (35,723); High School Seniors (34,981). RESPONDENTS: High Schools (1,015); High School Seniors (28,240); High School Sophomores (30,030). RESPONSE RATE: High Schools (1,015=90.5%); High School Sophomores (30,030=84%); High School Seniors (28,240=80.5%). FREQUENCY: Periodic. YEAR OF EARLIEST DATA: 1980. (SLD)