A framework for planning and facilitating video-based professional development.

Background: Recent transformative changes in science education require new learning opportunities for teachers-opportunities that include rich images of classroom enactment of the reform vision. One fruitful way for doing that is to use video clips of instruction.Teachers do not, however, learn how to improve their instructional practice from simply watching and reflecting on classroom videos.

Designing, facilitating, and scaling-up video-based professional development: supporting complex forms of teaching in science and mathematics.

This special issue brings together four effective video-based professional development programs-two in mathematics and two in science-that use classroom videos as the centerpiece of their efforts and have "scaling up" as their goal. In each paper, the authors surface their design considerations for creating scalable and sustainable video-based professional development interventions, including the challenges and successes they have experienced. The papers also emphasize the role of professional development facilitators in the scalability and sustainability of their programs and how best to support this emerging class of education professionals.