Education Week

In a move meant to ensure that school principals are instructional leaders, Illinois became the first state in the nation to create a specific endorsement for the lead role across pre-K through secondary schools. The state's move in 2010 has since led colleges and school districts to revamp how they prepare prospective principals to serve as leaders whose chief responsibility is to help teachers get better at instruction.

While some universities in the state are touting the benefits of that overhaul—which is still a work-in-progress—researchers and school district administrators are analyzing the pros and cons of the changes and reserving judgment on how well it has worked...