A number of recent studies have yielded data on the factors affecting the science achievement of disadvantaged students. For example, it was found that students' socioeconomic status (SES) increased as a predictor of their science achievement as the students moved through school. Furthermore, the effect of being Black (or, to a lesser degree, Hispanic) was similar to the effect of SES. Black students were shown in one study to perform best on science exercises most dependent on daily experience and common knowledge, and poorest on those that involve a detached research attitude toward the object and phenomena of science. Other studies found that poor and minority students are most affected by classroom factors such as too little time spent on science instruction and too much time spent on discipline, that Black students' science career plans are generally less related to their abilities than are Whites' plans, and that minority interest in science apparently does not lead to choosing the appropriate high school subjects for entering a science major in college. The research suggests a complex pool of attitudes and motivations that indirectly affect minority science preparation and the choice of a science career. These include attitudes and aspirations, stereotyping, role models, general academic success, cultural values, and parental influence and support. Research also suggests that the school counselor for whom ethnicity or sex make no difference can play a most important role in increasing enrollment of the disadvantaged in nonrequired science and mathematics courses. (KH)