Hand proximate user interfaces : design space for single-handed, always available and comfortable interface for head mounted displays

Head Mounted Displays (HMDs) are increasingly recognized as the next evolution of mobile computing. While HMDs offer a more seamless integration with the environment, they must overcome several challenges to reach their full potential. One significant area of focus is the interaction technique, particularly for 2D interactions such as navigating menus or browsing social media feeds. Although various interaction techniques exist, many have limitations - especially when compared to smartphones, the current de facto mobile computing platform. Inspired by smartphone interactions, this thesis proposes Hand Proximate User Interface (HPUI), in which interactive elements are anchored on and around the hand, and users interact with them using thumb-to-finger interactions. The visual cues of an HPUI enable novice users to operate it intuitively; they simply look at buttons anchored on their fingers and tap them as they would on a smartphone. Furthermore, it provides eyes-free affordance through proprioceptive and tactile cues, allowing users to rely increasingly on non-visual feedback as they become accustomed to a given interface layout. However, the interaction space of an HPUI exhibits unique characteristics, such as being non-contiguous and constantly changing shape as the fingers move. These contrasting properties of the HPUI give rise to two issues explored in this thesis through a series of user studies: (1) How should user interfaces for HPUIs be designed to incorporate the unique properties of their interaction surfaces? (2) Is the user experience of an HPUI affected by these properties? To address these questions, the thesis first explores and defines the design space of an HPUI. It then develops guidelines for creating applications using HPUIs. Next, the thesis validates that displaying content on the hand and interacting with it directly is advantageous, demonstrates that the performance of an HPUI is comparable to that of similar interaction techniques, and validates HPUI’s eyes-free affordance. Finally, the thesis introduces an HPUI toolkit to enable future researchers and designers to incorporate HPUI into their work.