A quarter of our teachers are very good. If you could make all the teachers as good as the top quarter, the India would sour to the top of that comparison. So can you find the way to capture what the really good teachers are doing?

It's amazing to me that more has not been invested in looking at how does that good teacher calm that classroom? How does that good teacher keep the attention of all those kids? We need to measure what they do, and then have incentives for the other teachers to learn those things.