#357: Collaborative High School Teacher Learning in Bichronous Online STEM Professional Development

This study examines how a bichronous model supports collaborative teacher learning in a four-week online bioinformatics professional development. Through analysis of nine high school teachers’ 1,363 asynchronous forum posts and 220 minutes of synchronous sessions, we identified complementary pathways: asynchronous forums supported knowledge building through archived threads and peer resource sharing, while synchronous sessions facilitated real-time collective sensemaking and expert scaffolding. Findings offer design principles for online teacher professional development in emerging STEM domains.