When it comes to professional practice, getting a clear picture of how you're teaching in the classroom is easier said than done. The instructional coaches and teachers whom the author interviewed as part of a study on using video in professional development were, in almost all cases, surprised by what they saw in a video of them teaching. In many cases, they were shocked. Drawing on his research, the author suggests that when video is used in a manner that respects the professionalism of teachers, it can have a positive effect on teaching and learning because it provides a clear picture of reality and a way for measuring progress toward a goal. The author presents four ways that schools can use video: 1) in instructional coaching, 2) in teacher evaluation, 3) with teams, and 4) individually as teachers coach themselves. Knight also warns education leaders not to push the use of video in a heavy-handed, compulsory way. "That's a recipe for disaster," he writes. Knight suggests six guidelines school leaders need to follow to ensure the productive use of video in their professional development efforts.