Chapter 6. Activating learners. The impact of peer coaching with video on teaching and learning in collaboration with Harmen Schaap Abstract In this in-depth, mixed-methods case study, 45 experienced secondary teachers engaging in reciprocal peer coaching with video were followed over seven years. Four cohorts participated, each during one school year. The teachers observed, filmed, viewed, discussed and gave feedback on each other’s lessons in two settings: pair work in their classrooms and plenary team meetings. Their overarching goals were: increasing variety in learning activities; increasing opportunities for differentiation; and promoting self- directed learning. The findings show that the teachers strengthened and expanded their teaching repertoires, while pupils positively rated the teaching behaviours targeted. Most outcomes were achieved for the goal of increasing variety in learning activities, both during and after peer coaching. Teachers’ lessons became less dominated by their own instruction and came to consist more of content-focussed dialogue. The main working mechanisms fostering changes in teaching were lesson observation, peer feedback and video viewing, analysis and discussion. The teachers succeeded in translating their thoughts about instruction into actions by moving through repeated cycles of planning, teaching and reflection. The main conclusion is that reciprocal peer coaching with video has the potential to alter the interplay between teaching and learning by eliciting and driving changes in teachers’ classroom behaviour. This type of collegial collaboration can bring about sustainable increases in the quality of instruction and encourage teachers to shift their instruction towards more dialogic forms of teaching and learning. What makes this study ground-breaking is that it demonstrates not only that VTL can foster sustainable changes in instruction, but also how. See YouTube for two lectures about this study (in German): • Videobasiertes peer Coaching als Strategie zur Entwicklung der Unterrichtskompetenz (Leuphana Universität Lüneburg, 20 April 2018) • Videofeedback: ein Hebel zur Qualitätssteigerung des Lehrens (Universität Zürich 28 March 2022)