Communication in collaboration, especially synchronous, remote communication, is crucial to the success of task-specific goals. Insufficient or excessive forms of communication may lead to detrimental effects on task performance while increasing mental fatigue. However, identifying which combinations of communication modalities provide the most efficient transfer of information in collaborative settings will greatly improve collaboration. To investigate this, we developed a remote, synchronous, asymmetric VR collaborative assembly task application, where users play the role of either mentor or mentee, and were exposed to different combinations of three communication modalities: voice, gestures, and gaze. Through task-based experiments with 25 pairs of participants (50 individuals), we evaluated quantitative and qualitative data and found that gaze did not differ significantly from multiple combinations of communication modalities. Our qualitative results indicate that mentees experienced more difficulty and frustration in completing tasks than mentors, with both types of users preferring all three modalities to be present.

Virtual Reality (VR) systems are widely used, and it is essential to know if spatial perception in virtual environments (VEs) is similar to reality. Research indicates that users tend to underestimate distances in VR. Prior work suggests that actual distance judgments in VR may not always match the users self-reported preference of where they think they most accurately estimated distances. However, no explicit investigation evaluated whether user preferences match actual performance in a spatial judgment task. We used blind walking to explore potential dissimilarities between actual distance estimates and user-selected preferences of visual complexities, VE conditions, and targets. Our findings show a gap between user preferences and actual performance when visual complexities were varied, which has implications for better visual perception understanding, VR applications design, and research in spatial perception, indicating the need to calibrate and align user preferences and true spatial perception abilities in VR.

Chronic lower back pain due to improper lifting techniques poses a major workplace safety hazard. The major risk factors for improper loading posture (ILP) include overloading, and improper loading of the lumbar muscles, ligaments, and vertebrae due to repetitive mechanical stresses exerted upon them. The current intervention technology relies on the users’ intent and willingness to self-correct ILP through alert-based feedback or involves wearing bulky lift assist devices to prevent ILP. We address these issues with a physiological feedback system that utilizes IMU sensors for ILP detection and Electrical Muscle Stimulation (EMS) for automatic dynamic ILP correction for restoring ideal lifting angles for torso inclination and knee bend. In a user study involving 36 participants, our automatic approach delivered significantly faster correction and outperformed alternative feedback mechanisms (Audio and Vibro-tactile) and was perceived to be interesting, comfortable and a potential commercial product.

We present a taxonomy of human-centered collaborative XR tasks. XR technologies have extended into the realm of collaboration, improving the quality and accessibility of teamwork. However, after a comprehensive assessment of the literature on the interaction between XR technologies and collaboration, no comprehensive method that emphasizes task actions and properties exists to classify collaborative tasks. Thus, our suggested taxonomy represents a classification system for collaborative tasks. After conducting a thorough literature review across different research venues, we conducted several exhaustive classification and review cycles for over 800 papers collected, which resulted in 148 papers retained to create the taxonomy. We dissected the actions and properties that the collaborative endeavors and tasks of these papers encompass as well as the types of categorizations and relations these papers illustrate. We expand on the design choices and usage of our taxonomy, followed by its limitations and future work. We built this taxonomy in order to reduce ambiguities and confusion regarding the design and comprehension of human-based collaborative tasks that use XR technology, which could prove useful in aiding the development and understanding of these tasks. Our taxonomy reveals a framework for understanding how collaborative tasks are designed and a systematic way of classifying different methods by which people can collaborate and interact in environments that involve XR, while still promoting efficient communication, teamwork, goal achievement and productivity.

Standard selection techniques such as ray casting fail when virtual objects are partially or fully occluded. In this paper, we present two novel approaches that combine cone-casting, world-in-miniature, and grasping metaphors to disocclude objects in the representation local to the user. Through a within-subject study where we compared 4 selection techniques across 3 levels of object occlusion, we found that our techniques outperformed an alternative one that also focuses on maintaining the spatial relationships between objects. We discuss application scenarios and future research directions for these types of selection techniques.

Gesture recognition systems using nearest neighbor pattern matching are able to distinguish gesture from non-gesture actions by rejecting input whose recognition scores are poor. However, in the context of gesture customization, where training data is sparse, learning a tight rejection threshold that maximizes accuracy in the presence of continuous high activity (HA) data is a challenging problem. To this end, we present the Voight-Kampff Machine (VKM), a novel approach for rejection threshold selection. VKM uses new synthetic data techniques to select an initial threshold that the system thereafter adjusts based on the training set size and expected gesture production variability. We pair VKM with a state-of-the-art custom gesture segmenter and recognizer to evaluate our system across several HA datasets, where gestures are interleaved with non-gesture actions. Compared to alternative rejection threshold selection techniques, we show that our approach is the only one that consistently achieves high performance.

Training simulations in virtual reality (VR) have become a focal point of both research and development due to allowing users to familiarize themselves with procedures and tasks without needing physical objects to interact with or needing to be physically present. However, the increasing popularity of VR training paradigms raises the question: Are VR-based training assessments accurate? Many VR training programs, particularly those focused on inspection tasks, employ simple pass or fail assessments. However, these types of assessments do not necessarily reflect the user’s knowledge.