Supplementary Data: Efficient VR-AR Communication Method using Virtual Replicas in XR Remote Collaboration

When using Virtual Reality (VR) and Augmented Reality (AR) to support remote collaboration, effective communication between a remote expert in VR and a local worker in AR is important for guiding and following task instructions. This is especially crucial for assembly tasks, which require precise identification of parts and clear directions for their combination. Despite the increasing interest in efficient VR-AR communication methods, previous studies have been limited to complex hardware setups and simplified assembly tasks. In this research, we introduce a communication approach for remote collaboration in complex assembly tasks, utilizing simplified hardware configurations. We conducted a user study (n=30) and compared three interaction interfaces (hand gestures, 3D drawing, and virtual replicas) in task completion time, subjective questionnaires, and preference rank. The results showed that the use of virtual replicas not only enhances task efficiency but also receives strong preference by users. These findings indicate that virtual replicas can provide intuitive instructions to local workers, resulting in a clearer understanding of the expert's guidance.