Richard Skarbez

Presence and plausibility are well-studied in virtual reality (VR), where psychophysical methods such as configuration transitions and budget allocation have been used to identify which environmental factors matter most for quality experiences. Whether these methods and findings generalize to augmented reality (AR), where virtual content coexists with the real world, remains largely unexplored. We extend the configuration-transition paradigm to optical see-through AR using a HoloLens 2, asking 30 participants to sequentially upgrade three factors of an AR tabletop scene: interaction level (none, near, near+far), physical behavior (none, applied forces, applied forces+collisions,+gravity), and shadow quality (none, hard, soft). Participants performed forced-choice upgrades while we recorded transition sequences, which we analyzed using Markov chains, and completed a separate budget-allocation task. Results converged across measures: 77% of participants upgraded interaction first, and near interaction, that is, the ability to grab and manipulate objects within reach, emerged as the dominant factor. Notably, richer interaction modalities such as remote manipulation were largely declined, suggesting that baseline interactive capability, rather than maximal interaction richness, is what drives plausibility in AR. Physics, particularly gravity, was the second priority, while shadow quality was consistently ranked last. A post-task plausibility questionnaire corroborated these behavioral findings. Our results suggest that for object manipulation in near action space, baseline interactive capability and physical coherence with real-world priors (e.g., gravity) contribute more to perceived plausibility than rendering enhancements such as shadows. These findings extend VR presence theory to AR and offer practical guidance for this class of AR experience: AR developers should prioritize responsive interaction and physically plausible behavior before investing in visual refinements.

Most histories of virtual, augmented, or mixed reality—hereafter collectively referred to as xR —place the origin of modern xR as Ivan Sutherland’s work at the University of Utah in the 1960s. “Virtual reality,” however, had not yet come to be. Outside of Sutherland’s work, the first academic articles describing what we would now call xR appeared only in the late 1980s, 20 years after Sutherland’s work. This article traces the evolution of xR from those early mentions to the present day, highlighting and surveying the key topics through a novel scientometric analysis of the literature.

Extended reality (XR) can be a valuable tool for knowledge workers. This idea is reflected in the advertisements for current XR devices, which promote them as productivity tools. However, a future work culture in which XR plays a significant role involves a variety of research areas, many of which are arguably not well explored yet. Through expert discussions, we identified 10 challenges in this emerging field, which are presented and discussed here. These challenges cover a diverse set of topics ranging from technological aspects, such as hardware or interaction, to content design and collaboration. They also include more human centric-topics concerned with work-life boundaries, health effects, social aspects, and accessibility. We also address challenges in industry and regarding privacy and security. Therefore, this article contributes an overview of research directions and open challenges for realizing the potential of XR for the future of work.

In this abstract, we discuss the demand for replication and extension efforts related to two seminal studies focused on virtual reality (VR) locomotion interfaces, initially centered around a VR implementation of the Visual Cliff, often referred to as Virtual Pit. The original experiments by Slater et al. (1995) and Usoh et al. (1999) compared different locomotion methods, including Real Walking, Walking-in-Place, and Flying/Steering, with a focus on presence and ease of use. We discuss the importance of these studies for the field, motivate replication efforts focused on these studies, discuss potential confounding factors, and present considerations for a concerted effort to reproduce the findings with state-of-the-art VR systems and measures, extensions to locomotion methods like Teleportation, and means to support future replications and extensions.

Experiences of virtual reality (VR) can easily break if the method of evaluating subjective user states is intrusive. Behavioral measures are increasingly used to avoid this problem. One such measure is eye tracking, which recently became more standard in VR and is often used for content-dependent analyses. This research is an endeavor to utilize content-independent eye metrics, such as pupil size and blinks, for identifying mental load in VR users. We generated mental load independently from visuals through auditory stimuli. We also defined and measured a new eye metric, focus offset, which seeks to measure the phenomenon of “staring into the distance” without focusing on a specific surface. In the experiment, VR-experienced participants listened to two native and two foreign language stimuli inside a virtual phone booth. The results show that with increasing mental load, relative pupil size on average increased 0.512 SDs (0.118 mm), with 57% reduced variance. To a lesser extent, mental load led to fewer fixations, less voluntary gazing at distracting content, and a larger focus offset as if looking through surfaces (about 0.343 SDs, 5.10 cm). These results are in agreement with previous studies. Overall, we encourage further research on content-independent eye metrics, and we hope that hardware and algorithms will be developed in the future to further increase tracking stability.

Affective - that is, emotionally aware - interactions with virtual humans contribute to improved user experience in both immersive and non-immersive virtual worlds. Some important open problems in this area are how to generate plausible moment-to-moment emotions in virtual humans, how to enable and model the transfer of emotions between multiple virtual humans, and how these emotions change and are changed by the environment. Motivated by these open questions, this paper presents a simulation study for the computational models of emotion and its shift and transference between characters.

Characterizations of presence are many and various. The first part of this article applies philosophical and psychological lenses to three common descriptions: Presence as (or as following from) “the suspension of disbelief,” presence as the “illusion of nonmediation,” and presence as “(the feeling of) being there.” These construals of presence—the assumptions and commitments they make—are compared with one another, their plausibility and utility appraised. The second, shorter part of the article is not so much interested in definitions as distinctions that may help us ask better questions moving forward. We briefly consider the role of attention in presence, whether, when, or how presence is “binary,” and whether it is helpful to speak of presence in unmediated physical reality. A recurring theme throughout the article is whether a given understanding of presence (mis)construes the mind as monolithic: That is, as uniformly rational and consciously accessible. In closing, we suggest that researchers specify precisely what type of presence they're referring to whenever the concept is evoked; and that states such as involvement, absorption, and engagement be kept conceptually separate from presence, since they speak to “higher” cognitive functioning than simply feeling self-located in virtual environments, and indeed need not presuppose placeness or spatiality at all.

As virtual reality (VR) technology becomes cheaper, higher-quality, and more widely available, it is seeing increasing use in a variety of applications including cultural heritage, real estate, and architecture. A common goal for all these applications is a compelling virtual recreation of a real place. Despite this, there has been very little research into how users perceive and experience such replicated spaces. This article reports the results from a series of three user studies investigating this topic. Results include that the scale of the room and large objects in it are most important for users to perceive the room as real and that non-physical behaviors such as objects floating in air are readily noticeable and have a negative effect even when the errors are small in scale.