Augmented Reality (AR) interactions feature users interacting with virtual objects registered in the physical world. With contemporary AR experiences increasingly featuring interactions at distances, we conceptualized The Force, a technique that allows users to clone distant objects and manipulate their replicas. An empirical evaluation was conducted, comparing it against two well-established techniques including controller-based ray-casting and a gaze-based pinching technique in a pick-and-place task. We employed a within-subjects design, collecting data on both objective performance and subjective user experience. Results suggest that The Force allows for higher levels of accuracy and efficiency in medium-field tasks that require precision and fine motor control. Furthermore, we discovered avenues towards iteratively refining this technique. We go on to discuss the implications of our findings in an effort to facilitate better interactions in augmented reality.

Mixed reality (MR) interactions feature users interacting with a combination of virtual and physical components. Inspired by research investigating aspects associated with near-field interactions in augmented and virtual reality (AR & VR), we investigated how avatarization, the physicality of the interacting components, and the interaction technique used to manipulate a virtual object affected performance and perceptions of user experience in a mixed reality fundamentals of laparoscopic peg-transfer task wherein users had to transfer a virtual ring from one peg to another for a number of trials. We employed a 3 (Physicality of pegs) X 3 (Augmented Avatar Representation) X 2 (Interaction Technique) multi-factorial design, manipulating the physicality of the pegs as a between-subjects factor, the type of augmented self-avatar representation, and the type of interaction technique used for object-manipulation as within-subjects factors. Results indicated that users were significantly more accurate when the pegs were virtual rather than physical because of the increased salience of the task-relevant visual information. From an avatar perspective, providing users with a reach envelope-extending representation, though useful, was found to worsen performance, while co-located avatarization significantly improved performance. Choosing an interaction technique to manipulate objects depends on whether accuracy or efficiency is a priority. Finally, the relationship between the avatar representation and interaction technique dictates just how usable mixed reality interactions are deemed to be.

Active exploration in virtual reality (VR) involves users navigating immersive virtual environments, going from one place to another. While navigating, users often engage in secondary tasks that require attentional resources, as in the case of distracted driving. Inspired by research generally studying the effects of task demands on cybersickness (CS), we investigated how the attentional demands specifically associated with secondary tasks performed during exploration affect CS. Downstream of this, we studied how increased attentional demands from secondary tasks affect spatial memory and navigational performance. We discuss the results of a multi-factorial between-subjects study, manipulating a secondary task's demand across two levels and studying its effects on CS in two different sickness-inducing levels of an exploration experience. The secondary task's demand was manipulated by parametrically varying $n$ in an aural $n$-back working memory task and the provocativeness of the experience was manipulated by varying how frequently users experienced a yaw-rotational reorientation effect during the exploration. Results revealed that increases in the secondary task's demand increased sickness levels, also resulting in a higher temporal onset rate, especially when the experience was not already highly sickening. Increased attentional demand from the secondary task also vitiated navigational performance and spatial memory. Overall, increased demands from secondary tasks performed during navigation produce deleterious effects on the VR experience.

Cybersickness (CS) is one of the challenges that has hindered the widespread adoption of Virtual Reality (VR). Consequently, researchers continue to explore novel means to mitigate the undesirable effects associated with this affliction, one that may require a combination of remedies as opposed to a solitary stratagem. Inspired by research probing into the use of distractions as a means to control pain, we investigated the efficacy of this countermeasure against CS, studying how the introduction of temporally time-gated distractions affects this malady during a virtual experience featuring active exploration. Downstream of this, we studied how other aspects of the VR experience are affected by this intervention. We discuss the results of a between-subjects study manipulating the presence, sensory modality, and nature of periodic and short-lived (5-12 seconds) distractor stimuli across four experimental conditions: 1) no-distractors (ND); 2) auditory distractors (AD); 3) visual distractors (VD); 4) cognitive distractors (CD). Two of these conditions (VD and AD) formed a yoked control design wherein every matched pair of 'seers' and 'hearers' was periodically exposed to distractors that were identical in terms of content, temporality, duration, and sequence. In the CD condition, each participant had to periodically perform a 2-back working memory task, the duration and temporality of which was matched to distractors presented in each matched pair of the yoked conditions. These three conditions were compared to a baseline control group featuring no distractions. Results indicated that the reported sickness levels were lower in all three distraction groups in comparison to the control group. The intervention also increased the amount of time users were able to endure the VR simulation and avoided causing detriments to spatial memory and virtual travel efficiency. Overall, it appears that it may be possible to make users less consciously aware and bothered by the symptoms of CS, thereby reducing its perceived severity.

User representations are critical to the virtual experience, and involve both the input device used to support interactions as well as how the user is virtually represented in the scene. Inspired by previous work that has shown effects of user representations on the perceptions of relatively static affordances, we attempt to investigate how end-effector representations affect the perceptions of affordances that dynamically change over time. Towards this end, we empirically evaluated how different virtual hand representations affect users' perceptions of dynamic affordances in an object retrieval task wherein users were tasked with retrieving a target from a box for a number of trials while avoiding collisions with its moving doors. We employed a 3 (virtual end-effector representation) X 13 (frequency of moving doors) X 2 (target object size) multi-factorial design, manipulating the input modality and its concomitant virtual end-effector representation as a between-subjects factor across three experimental conditions: (1) Controller (using a controller represented as a virtual controller); (2) Controller-hand (using a controller represented as a virtual hand); (3) Glove (using a hand tracked hi-fidelity glove represented as a virtual hand). Results indicated that the controller-hand condition produced lower levels of performance than both the other conditions. Furthermore, users in this condition exhibited a diminished ability to calibrate their performance over trials. Overall, we find that representing the end-effector as a hand tends to increase embodiment but can also come at the cost of performance, or an increased workload due to a discordant mapping between the virtual representation and the input modality used. It follows that VR system designers should carefully consider the priorities and target requirements of the application being developed when choosing the type of end-effector representation for users to embody in immersive virtual experiences.

Inspired by previous works showing promise for AR self-avatarization - providing users with an augmented self avatar, we investigated whether avatarizing users' end-effectors (hands) improved their interaction performance on a near-field, obstacle avoidance, object retrieval task wherein users were tasked with retrieving a target object from a field of non-target obstacles for a number of trials. We employed a 3 (Augmented hand representation) X 2 (density of obstacles) X 2 (size of obstacles) X 2 (virtual light intensity) multi-factorial design, manipulating the presence/absence and anthropomorphic fidelity of augmented self-avatars overlaid on the user's real hands, as a between subjects factor across three experimental conditions: (1) No-Augmented Avatar (using only real hands); (2) Iconic-Augmented Avatar; (3) Realistic Augmented Avatar. Results indicated that self-avatarization improved interaction performance and was perceived as more usable regardless of the anthropomorphic fidelity of avatar. We also found that the virtual light intensity used in illuminating holograms affects how visible one's real hands are. Overall, our findings seem to indicate that interaction performance may improve when users are provided with a visual representation of the AR system's interacting layer in the form of an augmented self-avatar.