i think you'll be surprised if you know about michelle rhee and why she was brought income which is there's a nationwide kind of are on teachers going on which is fine but that teachers, get rid of them and then we will fix education. it's been like a bunch of presidents who want to be the president that fixed education. we can talk about whether that even make sense but in any case the idea was to get rid of the bad teachers. in a larger destructive feedback loop engendered by the valued added model is it hasn't gotten rid of bad teachers. it's been getting rid of good teachers because good teachers have been quitting, retiring early and most of all they been moving to affluent suburbs that don't have this scoring system. right now we have a nationwide shortage of teachers. i would argue this regime of this i'll take value added model has been very, very bad. >> at i think something that is especially in cities about this, we talk about algorithms and they can sound tacky and four, things we don't interact with, but another the algorithms that we're talking about that we both work on have