Well in my case I've read a couple books about KIPP looking for evidence that I was wrong, but I didn't find any. The problem is that while KIPP is probably the fastest way to improve kids performance on Things That Can Be Measured, there's a lot of research showing how this approach is really bad for kids. And the pro-KIPP literature doesn't take any of this into account. My problem with Gates specifically is that not only does he not know what these problems are, but even when told about them he has no interest in learning about them despite the fact that they are extremely serious.