Over the last two decades policymakers and researchers of most "stripes" have come to conclude that teachers make the most difference in raising student achievement, and strong principals are key to school improvement. As a result, a wide array of initiatives have been launched to attract non-traditional recruits to education, measure…

Although states have maintained a focus on recruiting and retaining teachers, many schools and districts still face daunting challenges in ensuring a qualified and competent teaching corps. It is particularly difficult for schools considered hard to staff-those with high concentrations of low-performing, low-income students; high teacher turnover;…