What is--or should be--the purpose of a teacher evaluation system? To compare teachers? To inform the public? To help teachers improve? Legislators might say that a teacher evaluation system's purpose is to remove bad teachers. Administrators might say that it is to assist them in matching teacher skills to specific groups of students. Parents…

In a private room at the back of a busy restaurant just outside of Tampa, Florida, drinks and appetizers went unnoticed as 12 diners sat around one large table and engaged in multiple rapid-fire conversations about professional learning. On one side of each conversation were representatives of Memphis (Tennessee) City Schools. The district was in…