The three-year report sought to identify what encourages girls to pursue math and science, and what barriers keep them from the subjects. In the 20 years prior to the study, experts believed that girls lacked interest and tried to combat their indifference. The report revealed that a missing factor – confidence – often precedes interest. Because many girls perceived math and science as difficult, they assumed they would fail and didn't take the classes. Parental support and positive expectations from teachers can reverse these negative prognoses. Unfortunately, both boys and girls believed that teachers deemed boys better at math and science. The study didn't examine whether the teachers did indeed think this way, or if the boys and girls were internalizing stereotypes.