Using voluntary and anonymous surveys, we have collected answers from more than 700 high school students about the types and sources of help they received with their science and engineering fair projects, the obstacles they encountered, the strategies they used to overcome obstacles, and the impact of science fairs on their interest in science and engineering. Based on our research, we suggest that incentivizing voluntary student participation and offering students the choice of science fair formats--both noncompetitive and competitive- would best achieve the broad educational aims of science and engineering fairs to aid in the development of the scientific leaders of the next generation and at the same time foster a better understanding of science among its laymen.