Data collected within this qualitative, multiple-case study included teachers' knowledge building preferences for written speech in a virtual community of practice (VCoP), blended learning, teacher professional development program. This data was analyzed using the theoretical tenets of Vygotsky's social constructivist learning theory. Through heterogeneous sampling, six sites were selected from 11 program participating schools, with 11 participating teachers purposively selected from these sites. Following semi-structured participant interviews, data were coded and analyzed, where the findings indicated that participants preferred the audiovisual learning content to the written activity format in the blended learning, VCoP teacher professional development program. Program developers may use the research findings to guide the development of VCoP content alternatives to singularly text based online professional development delivery models. Recommendations for future research include studies that address the impact of audiovisual VCoP content on knowledge building.