Digital technology has several features that can make it much easier for teachers to pay special attention to all their students.

I could name about a dozen paths, and you'd like to have a whole bunch of research on all those paths, and then, eventually, at least four to five companies with really significant financing try and get to big scale, going down and really trying to prove it out.

On the supply side, for innovation, you'd say, go look at those R&D budgets, and they haven't moved in the last 20 years. In the case of the US - which is the majority of R&D funding across every category you can name: health, energy, whatever - it's been about $5 billion a year from the Department of Energy.

I never took a day off in my twenties. Not one.

Software was changing so fast, so unbelievable, that that got very quick adoption.

I never took a day off in my twenties. Not one. And I'm still fanatical, but now I'm a little less fanatical.

An important re-engineering principle is that companies should focus on their core competence and outsource everything else.