Researchers attempting to identify factors that affect the participation of Mexican American females in science courses and careers studied cultural, social, and educational factors affecting 2,442 Arizona secondary school students. Questionnaire responses and interviews with the students and their teachers, counselors, and parents revealed that ethnic and sex differences in science and math courses taken increased over time, with Anglo males most likely to take or be interested in taking science and math and to plan for science and math careers. Cultural factors associated with science interest included language spoken in the home, academic competence, family orientation, and self-perceptions. Social factors affecting interest included parental and peer opinions of the importance of science and college attendance. Mexican American parents provided much general encouragement and support of science courses but little focused assistance. Mexican American girls anticipated negative reactions to their science interests. Educational factors included caring about science; trying hard in science classes; and perceptions of science usefulness and of the factors associated with interest in science and complex, non-linear relationships. Teachers and counselors can help students by providing current, non-sex-stereotyped career and education information. (SB)