I actually attended one of these types of schools in New Jersey. They are part of the vocational district, but are far from it. There was an entrance exam and

I actually attended one of these types of schools in New Jersey. They are part of the vocational district, but are far from it. There was an entrance exam and requirements, when I attended there were four schools: Marine Academy of Science and Technology (marine-biology with a heavy NJROTC component), High Technology High School (engineering), Academy of Allied Health and Science (where I attended and focused on medical careers) and the just opened in 2000 Communications High School (video, media, design, journalism). Since graduating in 2004 they've opened a fifth, Biotechnology High School. Though I do not have a career in medicine, I don't know anyone who attended these schools who would have traded it for anything. The academic program was one of the most rigorous in the state, and I felt truly prepared for college. The schools are consistently ranked near the very top of the US News rankings nationwide and publicly financed. The value is in the exposure, I still have a great interest in health and use that experience frequently, I'm even an EMT which I did as a senior elective there. In fact, there's even a YC founder who went to one of our schools. TL;DR: It's not so much specialization as it is a rigorous 4 year college prep program with exposure to a field you have interest in.