Does mixed reality influence joint action? Impact of the mixed reality setup on users' behavior and spatial interaction

Understanding how people effectively perform actions together is fundamental when designing Collaborative Mixed Reality (CMR) applications. While most of the studies on CMR mostly considered either how users are immersed in the CMR (e.g., in virtual or augmented reality) or how the physical workspace is shared by users (i.e., distributed or collocated), little is known about how their combination could influence user's interaction in CMR. In this paper, we present a user study (n = 46, 23 pairs) that investigates the effect of the mixed reality setup on the user's immersion and spatial interaction during a joint-action task. Groups of two participants had to perform two types of joint actions while carrying a virtual rope to maintain a certain distance: (1) Gate, where participants had to pass through a virtual aperture together, and (2) Fruit, where participants had to use a rope to slice a virtual fruit moving in the CMR. Users were either in a distributed or collocated setup and either immersed in virtual or augmented reality. Our results showed that the immersion type and location setup altered users' proxemics as well as the users' subjective experience. In particular, we noticed better task performance when users were in augmented reality and more considerable distances between players while interacting in a distributed setup. These results contribute to the understanding of joint action in CMR and are discussed to improve the design of CMR applications.