When people think the issue can be solved, it becomes a moral imperative to be part of the solution. We can do a lot more within our school districts to recruit aggressively, select people according to high standards, invest in their training and development, and foster and reward their leadership. Once we invest more in attracting, developing and retaining teachers, potential recruits will begin to see it as a profession worth considering.

Education is the most powerful tool countries have for boosting economic growth, increasing prosperity and forging more just, peaceful and equitable societies. Where educational deprivation exists, it breeds conflict and enables repression.

As a country [USA], we can attract more talented people to teaching by raising awareness of educational inequity and getting the public to understand from individual classrooms, schools, and cities that this is an issue that can be solved.

I have not seen that standardised tests make the profession less attractive, though some principals respond to them in a way that drives the best teachers out of their schools (by over-emphasising test prep in the school curriculum for example). On the other hand, great teachers want benchmarks to measure progress and tests can help with that.

The most reliable way to be certain of their classroom impact is through independent studies conducted by third-party organisations which compare the student growth in our corps members' classrooms to that of other teachers in similar situations.

The evidence would suggest that there are some great alternative certification programmes and some lousy ones. There are some wonderful traditional education schools, and some that aren't so effective. What's important is less the pathway than the impact on students.

The limitations of federal laws are able to create real progress at the local level. Ultimately, to effect not just incremental progress but progress that is transformational for students, we need committed leadership - people who believe deeply that their students can achieve at the highest levels and who know how to create the conditions at the classroom, school and system level to give them the opportunities they deserve.