Designed to examine the development of: (1) student attitudes toward and achievement in science, (2) student attitudes toward and achievement in mathematics, and (3) student interest in and plans for a career in science, mathematics, or engineering, during middle school, high school, and the first 4 years post-high school, and to estimate the relative influence of parents, home, teachers, school, peers, media, and selected informal learning experiences on these developmental patterns. The older LSAY cohort, Cohort One, consisted of a national sample of 2,829 tenth-grade students in public high schools throughout the United States. These students were followed for an initial period of 7 years, ending 4 years after high school in 1994. Cohort Two, consisted of a national sample of 3,116 seventh-grade students in public schools that served as feeder schools to the same high schools in which the older cohort was enrolled. These students were followed for an initial period of 7 years, concluding with a telephone interview approximately one year after the end of high school in 1994. Beginning in the fall of 1987, the LSAY collected a wide array of information from each student, including: (1) a science achievement test and a mathematics achievement test each fall, (2) an attitudinal and experience questionnaire at the beginning and end of each school year, (3) reports about education and experience from all science and math teachers in each school, (4) reports on classroom practice by each science and math teacher serving an LSAY student, (5) an annual 25-minute telephone interview with one parent of each student, and (6) extensive school-level information from the principal of each study school. In 2006, the NSF funded a proposal to re-contact the original LSAY students (now in their mid-30's) to resume data collection to determine their educational and occupational outcomes. Through an extensive tracking activity, more than 95 % of the original sample of 5,945 LSAY students were located or accounted for. A new eligible sample of approximately 5,000 students was defined and these young adults were asked to complete a survey in 2007. For more information, also see the LSAY website.