US schools have traditionally been characterized by teacher privacy and independence, yet theory and empirical work suggest that peer observation and support – or “de-privatized instruction” – can help improve pedagogical practice. In this randomized controlled trial, we investigate whether the introduction of video technology into a school, through a video- based teacher evaluation system called Best Foot Forward (BFF), led to instructional de-privatization. We find that BFF caused administrators to broker more peer support among teachers, made teachers more likely to share lesson videos with colleagues, led teachers to have more of their lessons seen by other teachers, and redistributed which teachers
were providing instructional support to colleagues (with relatively newer teachers taking on a larger role in providing peer support). Results suggest that video technology may be an effective tool for efforts to improve instruction by increasing peer observation and support.