Virtual Agents in Immersive Virtual Reality Environments: Impact of Humanoid Avatars and Output Modalities on Shopping Experience

Embodied virtual agents (EVAs) are used in various online shopping scenarios to enhance consumer experience. Humanoid avatars and output modalities of EVAs are two important factors affecting online shopping experience, which have been widely studied in shopping websites before. Moreover, immersive virtual reality (IVR) shopping is a future trend in online shopping, but research on EVAs in IVR environments is limited. The impact of them in an IVR shopping environment is not yet fully understood. Therefore, this study aims to investigate the effect of an EVA's humanoid avatar and output modalities on the online shopping experience in an IVR environment. First, 66 participants were invited to participate in a 2 (humanoid avatar: presence vs. absence) x 3 (output modalities: text-only, voice-only, and text and voice) within-group experiment to complete the specified purchase task. After each purchase task was completed, participants were required to fill in a subjective questionnaire to score the six different combinations of virtual agents (VAs). After all purchase tasks were completed, a follow-up interview was conducted to better obtain the participants' preferences and detailed reasons for the six different combinations of VAs. The results showed that humanoid avatars significantly enhanced participants' perceptions of warmth, communication, trust, and satisfaction. Additionally, output modalities significantly enhanced participants' perception of warmth, communication, trust, comfort, and satisfaction. Finally, the humanoid avatar and output modalities had significant interactions in terms of comfort. The results of this research provide theoretical reference and guidance for the design of VAs in IVR shopping environment, and also provide inspiration for the design and research of VAs in other online shopping environments.