Abstract
Online learning at scale has become dramatically more popular over the last decade. While these programs provide affordable and accessible education, low retention and engagement are persistent
problems. Virtual Teaching Assistants (VTAs) offer a solution: VTAs can answer questions about course logistics and content, amplifying interaction between professors and students, increasing teaching
presence, and thereby improving retention and engagement. Using the Community of Inquiry framework, this paper presents what we believe is the first experimental study of the effect a VTA has
on student perceptions of teaching presence, social presence, and cognitive presence. Students in a large, online, graduate computer science course were randomly assigned to sections with and without access to the VTA. The Community of Inquiry survey was then administered at the end of the semester to measure the three presences. We find that the VTA has a small, positive, statistically significant effect on the Design & Organization dimension of teaching presence as well as social presence.
