Great teaching is one of the inputs that will lead to student learning. In fact, it is one of the only inputs educators have control over. Because of this we invest time and money into providing high quality professional development and create opportunities for feedback so that teachers will improve and student academic achievement will likewise improve.
Unfortunately, we spend little time determining whether our professional development has been effective. We should not wait to see if student achievement increases to determine if our professional development efforts have been effective. We should be continuously monitoring what we expect to occur. A consequence of professional development should be a change in teacher behavior. Our only effective method for determining whether teachers are changing behavior is to observe them in action. In short, administrators should in the classroom observing whether their professional development efforts are impacting teacher behaviors.
I know people in education think that student achievement is an appropriate measure to determine the effectiveness of professional development, but it isn’t. If the point of professional development is to change the input (teaching practice), then that is what needs to be measured.