摘要: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. The videos need to be carefully selected and embedded in professional development in ways that-through facilitator-led, participant-centered discussion-can help teachers to notice and reason about important aspects of instruction and learning that occur in the video. Consistent with the recent efforts to identify planning and facilitation approaches that guide effective professional development (PD) programs, in this paper, we adapted the Five Practices Framework for orchestrating productive classroom discussions to describe how PD facilitators plan for and enact professional learning tasks to help science teachers learn within a video-based PD program. These practices include anticipating, sequencing, monitoring, selecting, connecting and two additional practices that set the stage for the five practices (i.e., setting goals and selecting tasks). Our analyses of the video-based discussions in the PD provide insights into how the facilitators engaged teachers in video-based conversations by using the practices of monitoring, selecting, and connecting. The monitoring moves, such as clarifying, countering, and redirecting, were used by the facilitator in nearly all the PD sessions. Similarly, selecting moves were used and were consistent with the goals of the PD. Finally, analysis of facilitators' and participants' connecting comments indicated their increased capacity to make connections to the bigger ideas of teaching science by maintaining the cognitive demand on students' thinking. This paper provides elaborated descriptions of the five practices for planning and facilitating video-based PD and the ways in which they were enacted in a video-based PD program in science. In so doing, it proposes five practices as a guiding framework to support teachers' learning from videos. Overall, the study's results endorse the promise of a goal-driven, theory-informed design that foregrounds careful attention to teachers' thinking in ways that support their understanding of complex classroom interactions.