It's hard to admit you were wrong. It's even harder to admit you were wrong in publicly backing the largest educational reform bill in a generation. So, it's all the more impressive that Diane Ravitch not only acknowledged that she had made a mistake by advocating the No Child Left Behind Act, but also wrote an entire book, "The Death and Life of the Great American School System: How Testing and Choice Are Undermining Education," about just how misguided that policy was.