School districts profoundly shape the destinies of their principals: how they are trained, hired, mentored, evaluated and developed on the job. Yet until recently, many educators and policymakers overlooked the vital role districts can play to help principals shoulder their central responsibility: improving teaching and learning.

Armed with new evidence about the importance of school leadership and how it can best be developed, a growing number of large districts are seeking to cultivate first-rate principals for all of their schools. Doing so requires two big commitments:

1. Build a large corps of well-qualified candidates for the principalship:
• Create job descriptions that clearly spell out the knowledge principals need and what responsibilities are key in order to drive better instruction.
• Improve pre-service principal training.
• Establish selective hiring procedures that identify the most promising future leaders and match them to the right schools.
• Ensure that hard-to-staff schools get top-quality leaders.
2. Support school leaders on the ground:
• Develop fair and reliable performance evaluations that hold principals accountable for student progress but also inform their ongoing training.
• Offer mentoring for novice principals and professional development for all principals, so school leaders can continually improve throughout their careers.
• Provide school leaders with timely, useful data and training on how to use it effectively.
• Enable principals to devote sufficient time to improving instruction as well as to making the best use of that time.
• Plan for orderly turnover and leadership succession.