This study examines the instructional experiences of a national sample of 1992 high school seniors in the subjects of science and mathematics. The study analyzes data from the National Education Longitudinal Study of 1988 (NELS:88). The information on instruction comes from the NELS:88 1992 survey of teachers, which collected questionnaires from the science and mathematics teachers of 9,853 sampled seniors enrolled in public and private high schools across the United States. Two general questions are addressed: To what extent are high school seniors' instructional experiences affected by their social backgrounds and by the schools they attend? Multiple regression analysis was used to sort out the influences of social background and schooling variables on instructional variables and achievement score differences. (Author)