Males are more likely than females to aspire to and attain careers in science. This pattern might be attributed to differences in the appeal of school science to boys and girls. In this study, 114 middle school students in grades 7 and 8 carried out versions of science experiments that differed in their motivational appeal. Findings showed that boys were more attentive to aspects of science experiments that elicit perceptions of control, whereas girls were more attentive to social aspects. Further, attempts to enhance the interest value of science experiments were found to be more effective for girls than boys. Motivational enhancement of science experiments was found to affect subsequent choices to participate in science experiments. An appendix discusses modifications to the experiment procedure. (Contains 2 tables, 3 figures, and 12 references.) (Author/SLD)