This short publication from AERA (The American Educational Research Association) was featured in this week's PEN Weekly NewsBlast-- Teaching Teachers: Professional Development To Improve Student Achievement.

The brief concludes with a sidebar labeled "What Should Policymakers Do?"

First, make sure that professional development focuses on the subject matter teachers will be teaching.
Second, align teachers' learning opportunities with their real work experiences, using actual curriculum materials and assessments.
Third, provide adequate time for professional development and ensure that the extended opportunities to learn emphasize observing and analyzing students' understanding of the subject matter.
Fourth, ensure that school districts have reliable systems for evaluating the impact of professional development on teachers' practices and student learning.