According to the text from DuFour, R.(2010), Raising the Bar and Closing the Gap: Whatever it Takes, what evidence of the three big Professional...

The three big ideas behind the concept of the Professional Learning Community is that they help students learn (not simply be taught); that they involve teachers in a collaborative process; and that schools monitor their effectiveness at helping students learn. Public schools nationwide offer scant evidence that they are helping students learn rather than be taught. High-stakes testing based on Common Core Standards measure students' responses in narrow ways that pay little attention to how much students are actually learning (rather than simply regurgitating). These tests also pay little attention to the process of learning, which is as important as the outcome. In addition, teachers, strapped for time to teach to the tests, do not have time to work collaboratively, and their assessment of their results is based on state tests rather than how effectively they have created a Professional Learning Community. 

To establish a Professional Learning Community, schools must measure the process of learning, rather than just the outcome. In other words, how are students asking questions and finding answers? These are the essential skills that schools should be measuring, not just responses to Common Core Standards-based tests. In addition, teachers need more professional development time to work collaboratively and hone their practice, and schools should measure how effectively they are modeling and teaching the process of learning, not just students' mastery of the Common Core.