Parallel or Cross? Effects of Two Collaborative Modes on Augmented Reality Co-located Operations

Augmented reality (AR) can bring a new interactive experience to the collaboration between users. When users are in the same place, there are two modes of joint operation for the same object: parallel-work (PW) and cross-work (CW). PW means two users perform their tasks, while CW means assisting each other. To investigate the difference that collaboration using PW and CW in an AR environment brings to users, we developed a two-person local collaboration system, LoCol. We designed and conducted user experiments by selecting the tasks of adjusting the virtual model of the assembly and adding missing boundaries in the model. The results showed that CW led to a higher sense of social coexistence while reducing workload. In terms of task completion time and accuracy, CW and PW each had advantages. We found that users generally want to reduce unnecessary repetitive operations and frequent movement by working with others. This is likely an important criterion for determining who is better suited for a particular job in either approach.