This study extends research on perspectival understanding (Greeno & van de Sande, 2007) by using Du Bois' (2007) discourse work on stancetaking to investigate how students expressed their perspectives on course content through a variety of stances/positions as they negotiated meaning in online discussions. Participants were students in a hybrid graduate-level course with weekly synchronous computer-mediated discussions. Adapting Du Bois' stancetaking triangle, we coded discussion transcripts for shifts in stance and for evidence of influence on students' perspective taking as they considered course concepts. Findings were that stances and stance objects (that is, topics) were introduced as students collaborated in discussion, with an epistemic stance indicating students' primary focus on wanting to learn and understand course concepts. Evaluative and affective stances were less frequent and most often intertwined with an epistemic stance but nevertheless important in supporting the group's discussion. Synchronous online discussions afforded a venue for iterative discourse interactions of evaluation, positioning, and alignment and for shared knowledge co-construction and perspectival understanding.