Quite a lot of international research has focused on the barriers. Depending on the age of the young people, the barriers are slightly different. At the high school level, it's a lack of role models; the lack of perceived relevance is actually quite large. Often the amount that's being taught is a mile wide and a mile deep, and the contextual basis is sometimes missing.
Another piece is a lack of career awareness. I have a 15-year-old daughter, and when she comes back after her math and physics class, she says, “Here's what I did today. I have no clue why I'm going to do this, or what job will ever ask me to do this again. I know I need to take science, because you're my mother, but....”