Just to deliver one high-quality 45 minute lesson requires many hours of planning in advance.

There's definitely a tension between the way teaching is talked about and understood at the political level and how everyday average Americans think about teachers.

I believe everyone in the education sector should be looking at evidence, reassessing, making tweaks to figure out what works, I think it's a positive model.

When you see that 76 percent of teachers are female, I think you have to acknowledge that there's a cultural bias, and it does date back to this nineteenth century idea that teaching is a form of mothering.

[Nineteenth century American educator] Catharine Beecher is really associated with the idea that a mother works with children in the home and a teacher works with children at school, and that therefore women are almost biologically predisposed to do this job.

There are a lot of polls that show that actually Americans have a pretty high opinion of teachers, that Americans think teachers are just about as prestigious as doctors. And yet there's this political conversation - this reform conversation - that paints a very negative picture of the effectiveness of the teaching population. So there's definitely a tension between the way teaching is talked about and understood at the political level and how everyday average Americans think about teachers.

I don't think school reform should be motivated by missionary zeal. I think it should be motivated by evidence of what works.