Historically, data quantifying the effect principals have on student outcomes has been hard to come by. But that's changing, with reseach from the Wallace Foundation indicating that principals are second only to teachers in their impact on achievement. A new report from the Center for Public Education, an initiative of the National School Boards Association, examines this research and more, compiling data on the role of principals.

According to the report, "The Principal Perspective," research indicates that:

• the job of the principal has changed dramatically;
• principals impact their students’ outcomes, particularly at the most challenging schools;
• principal turnover adversely impacts schools;
• effective principals retain and recruit effective teachers;
• principals become more effective as they gain more experience; and
• being an instructional leader is a hallmark of an effective principal.

While principals influence student success at all grade levels, the report highlights a 2010 study which found elementary principals have a higher impact on student achievement than principals at the middle or high school levels. This may be because, researchers speculate, principals at elementary schools spend more time in classrooms than principals at other levels, and typically have a stronger role as instructional leaders.

Read the full report here.

-By Emily Rohlffs