Effects of User Interface Orientation on Sense of Immersion in Augmented Reality

The sense of immersion provided by overlying computer-generated graphics over actual items is one of augmented reality's distinguishing features. It is affected by multiple factors such as the user interface orientation in the virtual physical hybrid space. There have been many studies on realistic graphic rendering and multimodal interaction in augmented reality. Few studies, however, have systematically investigated the influence of the user interface orientations, more specifically the user-based orientation (UO) and object-based orientation (OO), on various aspects of immersion. We developed the UO and OO user interface prototypes and evaluated the sense of immersion in terms of engagement, engrossment, and overall immersion. The results showed that the user interface orientations in augmented reality had a significant influence on users' perceived engagement and engrossment, whereas there was no significant difference in overall immersion. Particularly, compared to the OO user interfaces, the UO user interfaces exhibited higher perceived usability and slower focus of attention switching. Generalising implications for alternative augmented reality are provided.