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.

The most successful teachers in low-income communities operate like successful leaders. They establish a vision of where their students will be performing at the end of the year that many believe to be unrealistic. They invest their students in working harder than they ever have to reach that vision, maximise their classroom time in a goal-oriented manner through purposeful planning and effective execution, reflect constantly on their progress to improve their performance over time, and do whatever it takes to overcome the many challenges they face.

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.

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.

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.

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.