Using school records, questionnaires, interviews, and psychological tests, researchers studied the factors affecting academic achievement in a large, urban, technical high school. For 20 high-achieving and 20 low-achieving seniors, data were gathered on sex, ethnicity, personality factors, high school and college entrance test scores, grade point averages, areas of concentration, attendance, activities, study habits, school motivation, academic self-concept, self-perception of problems, successes, failures, and influences of peers, family, and school personnel on decisions regarding school, program, and college selection. Information came not only from students but also from parents, teachers, and friends. Crosstabulation of the data led the authors to conclude that family influences strongly affect achievement through their impact on student self-confidence and independence; that peer networks, or school culture, are important influences on program and college decisions; that female students have a higher self-image and better achievement records; and that gender and ethnicity are related to student independence and motivation, which in turn affect student achievement. (RW)