Investigated were the outcomes of student participation in science fair projects. The 952 students were stratified for science project experience, choice of career, type of project, type of award, record of project making, motivational factors and reaction to project making. Conclusions included the following: (1) Science projects were not significant factors in student achievement or interest in science. (2) Students who participated in science project making did not receive significantly higher ratings in science from their teachers. (3) Students with investigation type projects excelled in achievement over students who make construction projects, but did not excell over students who made demonstration projects or made none at all. (4) The type of project was not a significant factor in student science interest. (5) The more years of a student's participation in project activities, the greater the possibility he had chosen science as a career and the lesser the possibility he had chosen a personal-social or mechanical career. (GR)