Behavioral Measures of Copresence in Co-located Mixed Reality

View of the physical space with two participants. Center: Point of view of a participant seeing several walls approaching them. Right: An annotated view of the virtual environment: The participant (1), task area (2), guard rails (3), lanes (4), lane feedback (5), position feedback (6), walls (7), and score (8) Abstract-When several people are co-located and immersed in a mixed reality environment, they may feel like they share the virtual environment or not. This feeling of copresence, along with its parent dimensions of social presence and presence, has been mostly studied by relying on subjective measures gathered through questionnaires. As a way to address the drawbacks of this approach, we introduce a protocol to gather behavioral measures in the context of co-located mixed reality. As a pair of participants avoid obstacles moving towards them, their errors, gaze, interpersonal distance, and timing are measured. By combining subjective measures gathered through a questionnaire drawing from previous studies on social presence with behavioral measures, we demonstrate new ways to assess how users experience copresence. We illustrate this protocol by evaluating the effect of visual feedback on collaborators' activity. The results of this experiment suggest the capability of our protocol by revealing the effect of visual feedback on both objective and subjective measures.