Using base year survey data from the National Longitudinal Study of the High School Class of 1972 and High School and Beyond, this report compares and contrasts the nation's seniors of 1972 and 1980. Over 1,600 seniors participated in the first study, approximately 28,000 in the second. Chapter I provides an introductory overview of educational, social, demographic, and economic trends and changes in American society. Chapter II compares the seniors with regard to school experiences (curricula, courses, extracurricular activities, and federally funded programs) and students' evaluations of teaching methods, their schools and their educations. Chapter III examines changes in levels of school performance as judged by verbal and mathematics tests, homework effort, and grade-point average. Chapter IV looks at self-perceptions, based on measures of locus of control and self esteem, and life and work values. Chapter V examines plans and aaspirations; short term plans; influence of school staff on plans; planned field of study in college; postsecondary occupational plans; and occupational goals. Appendix A contains nine tables of estimated changes by sex, race, socioeconomic status, test score, high school program, and geographic region. Appendix B discusses potential sources of error in the data. (BS)