Hybrid meetings are the new reality, yet they lack the richness of face-to-face interaction. In shared spaces, virtual or physical, interaction relies on more than words: proximity, non-verbal cues, and subtle movements all shape communication. Proximity captures how close we stand, where we face, and how we move around others. This paper investigates how proxemics in dyad and triad conversations translate across physical and virtual contexts. We conducted a study with 24 participants in four groups, completing social tasks under four conditions: face-to-face, co-located XR, remote XR, and hybrid XR. Our instrumentation of physical and virtual environments enables direct comparison. The work contributes a rich open dataset of 2.3 million rows across 32 columns, supporting comparative and replicable analysis. This is the first study to compare proxemics across face-to-face, co-located XR, remote XR, and hybrid XR, offering a foundation for understanding how social space translates across contexts.

Immersive realities enable social interactions that are radically different from traditional communication technologies, but how we experience immersion together is not yet indistinguishable from face-to-face interactions. Some social signals are not stable across realities, may change in semantics, or are missing all together. Understanding how social signals impact behaviours and experiences of social connection in immersive environments is key to creating experiences that are meaningful, satisfying, and productive. We completed a lab study where 6 groups of 6 participants (N=36) completed co-located social tasks in an instrumented face-to-face environment and its digital twin, creating a rich open dataset of 1.8 million rows across 45 columns. Our quantitative results demonstrate the stability of position as a social signal, measure lower social synchronisation in XR compared to face-to-face, and propose a method for bench marking XR against face-to-face interactions. This enables direct quantitative comparisons between experiences of co-located physical and virtual interactions for the first time.

Immersive technologies allow us to personalize our reality while traveling; however, widespread adoption remains limited. This study investigates the challenges of adopting immersive devices in transit, particularly when passengers encounter asymmetric experiences using disparate devices. These situations arise as co-located passengers adopt devices with varying levels of immersion, environmental information, and interactive capabilities. Using an enactment methodology in a transit scenario involving disparate devices, our study (N = 21) reveals that asymmetric passenger experiences create a sense of disconnection among passengers, especially with varying device immersion capabilities. When interactions require more than a basic response, for example complex verbal exchanges relying on social cues like gaze, adoption is further hindered. The incorporation of cues from reality addresses safety concerns but requires further refinement to support interactions that require complex or extended user involvement. This research advances the understanding of asymmetric passenger dynamics, contributing to the design of immersive technologies for transit settings.

Electrical Muscle Stimulation (EMS) has unique capabilities that can manipulate users’ actions or perceptions, such as actuating user movement while walking, changing the perceived texture of food, and guiding movements for a user learning an instrument. These applications highlight the potential utility of EMS, but such benefits may be lost if users reject EMS. To investigate user acceptance of EMS, we conducted an online survey (N = 101). We compared eight scenarios, six from HCI research applications and two from the sports and health domain. To gain further insights, we conducted in-depth interviews with a subset of the survey respondents (N = 10). The results point to the challenges and potential of EMS regarding social and technological acceptance, showing that there is greater acceptance of applications that manipulate action than those that manipulate perception. The interviews revealed safety concerns and user expectations for the design and functionality of future EMS applications.

Virtual Reality (VR) headsets allow us to personalise how we experience reality while travelling, offering benefits over traditional devices. VR that incorporates elements of reality could be crucial to creating safe and socially acceptable VR experiences by supporting VR users to be aware of the ever-changing transit environment, and the presence and actions of bystander passengers. Our study (N=14) examines VR in-the-wild on real train journeys to explore how VR users desire to employ passthrough style ‘portals’ to reality, and what impact these portals have on their perceived safety, social acceptability, and more in a real passenger context. We utilised a qualitative methodology with user interviews to evaluate experiences after real train journeys. Our findings indicate a favourable response to VR use on public transport, particularly when travelling alone. Portals effectively mitigate safety, awareness, and social concerns, but also pose challenges in simultaneously engaging with real and virtual environments. Users show a preference for passive monitoring of real-world changes over the more demanding active checking of the portals. However, this can lead to 'information wormholes,' where changes in the real-world slip past the portals. This study provides ecological validity to adopting VR in real transit settings and offers insights for the further development of reality-awareness systems.

Virtual reality (VR) users are often around bystanders, i.e. people in the real world the VR user may want to interact with. To facilitate bystander-VR user interactions, technology-mediated awareness systems have been introduced to increase a user’s awareness of bystanders. However, while prior works have found effective means of facilitating bystander-VR user interactions, it is unclear when and why one awareness system should be used over another. We reviewed, and selected, a breadth of bystander awareness systems from the literature and investigated their usability, and how they could be holistically used together to support varying awareness needs across 14 bystander-VR user interactions. Our results demonstrate VR users do not manage bystander awareness based solely on the usability of awareness systems but rather on the demands of social context weighted against desired immersion in VR (something existing evaluations fail to capture) and show the need for socially intelligent bystander awareness systems.

Immersive technologies allow us to control and customise how we experience reality, but are not widely used in transit due to safety, social acceptability, and comfort barriers. We propose that cues from reality can create reference points in virtuality, which we call Reality Anchors, will reduce these barriers. We used simulated public transportation journeys in a lab setting to explore Reality Anchors using speculative methods in two studies. Our first study (N=20) explored how elements of reality like objects, furniture, and people could be used as anchors, demonstrating that visibility of other passengers and personal belongings could reduce barriers. Our second study (N=19) focused on journey types that emerged from the first study - self-managed vs. externally managed journeys - revealing that self-managed journeys increased the need for anchors. We conclude that Reality Anchors can reduce concerns associated with immersive technology use in transit, especially for self-managed journeys.

Despite recent work investigating how VR users can be made aware of bystanders, few have explored how bystander-VR user interactions may be facilitated by, for example, increasing the user’s auditory awareness so they can better converse with bystanders. Through a lab study (N=15) we investigated 4 approaches of manipulating in-VR audio to facilitate verbal interactions between a VR user and bystander: (1) dynamically reducing application volume, (2) removing background audio, (3) removing sound effects and (4) removing all audio. Our results show audio manipulations can be used to significantly improve a VR user’s auditory awareness at the cost of reducing sense of presence in VR. They also show most preferred increased awareness be balanced with decreased presence in VR, however, they also identify a subset of participants who prioritised increasing awareness no matter the cost to presence.

Behaviour in virtual environments might be informed by our experiences in physical environments, but virtual environments are not constrained by the same physical, perceptual, or social cues. Instead of replicating the properties of physical spaces, one can create virtual experiences that diverge from reality by dynamically manipulating environmental, aural, and social properties. This paper explores digital proxemics, which describe how we use space in virtual environments and how the presence of others influences our behaviours, interactions, and movements. First, we frame the open challenges of digital proxemics in terms of activity, social signals, audio design, and environment. We explore a subset of these challenges through an evaluation that compares two audio designs and two displays with different social signal affordances: head-mounted display (HMD) versus desktop PC. We use quantitative methods using instrumented tracking to analyse behaviour, demonstrating how personal space, proximity, and attention compare between desktop PC and HMDs.

The occlusive nature of VR headsets introduces significant barriers to a user’s awareness of their surrounding reality. While recent research has explored systems to facilitate a VR user’s interactions with nearby people, objects, etc, we lack a fundamental understanding of user attitudes towards and expectations of these systems. We present the results of a card sorting study (N=14) which investigated attitudes towards increasing a VR user’s reality awareness (awareness of people, objects, audio, pets, and systems to manage and moderate personal usage) whilst in VR. Our results confirm VR headsets should be equipped with systems to increase a user’s awareness of reality. However, opinions vary on how increased awareness should be achieved as our results also highlight differing expectations regarding: persistent vs temporary notification design, notification content and when, why and how awareness should be increased.

Passengers spend considerable periods of time in shared transit spaces, relying on smartphones and laptops for work. However, these displays are limited in size and ergonomics compared to typical multi-monitor setups used in the office, impairing productivity. Augmented Reality (AR) headsets could provide large, flexible virtual workspaces during travel, enabling passengers to work more efficiently. This paper investigates the factors affecting how passengers choose to layout virtual displays in car, train, subway and plane environments, studying the affordances of each mode of transport and the presence of others. Results from our experiment showed: significant usage of the physical environment to align displays; strong social effects meant avoiding placing displays over other passengers or their belongings; and use of displays for shielding oneself from others. Our findings show the unique challenges posed by the mode of transport and presence of others on the use of AR for mobile productivity in the future.

Virtual environments (VEs) can create collaborative and social spaces, which are increasingly important in the face of remote work and travel reduction. Recent advances, such as more open and widely available platforms, create new possibilities to observe and analyse interaction in VEs. Using a custom instrumented build of Mozilla Hubs to measure position and orientation, we conducted an academic workshop to facilitate a range of typical workshop activities. We analysed social interactions during a keynote, small group breakouts, and informal networking/hallway conversations. Our mixed-methods approach combined environment logging, observations, and semi-structured interviews. The results demonstrate how small and large spaces influenced group formation, shared attention, and personal space, where smaller rooms facilitated more cohesive groups while larger rooms made small group formation challenging but personal space more flexible. Beyond our findings, we show how the combination of data and insights can fuel collaborative spaces’ design and deliver more effective virtual workshops.

This paper investigates three types of user interface: VR, Gesture-based, and Tangible. We examine how user experience differs across these different technologies, and explore the factors that underpin the differences. We conduct an empirical study, in which we create three different interactive exhibits that apply these technologies to deliver the same scientific content. The study uses a mixed-method approach to measure two factors. First, user experience is measured accorded to six dimensions of user experience: attractiveness, perspicuity, efficiency, dependability, simulation, and novelty. Second, attention holding power is measured by playing time. The study uses semi-structured interviews to explore the user experience and learning outcomes afforded by each interface. Thirty-one subjects took part the study. The results show that there are significantly different user experiences when using different types of interface. There are differences across five user experience dimensions; only novelty is relatively unchanged. Differences are found primarily between the VR and Gesture, and Tangible and Gesture conditions. No significant difference in holding power between the three types of interface was observed. The statistical analysis of results and interview data from participants suggest six aspects to focus on when choosing an alternative interface for a new interactive exhibit: novelty, user-friendliness, precision of the input device, task and device design, multi-modality of feedback, and quality of text in VR.

Augmented / Mixed Reality headsets will in-time see adoption and use in a variety of mobility and transit contexts, allowing users to view and interact with virtual content and displays for productivity and entertainment. However, little is known regarding how multi-display virtual workspaces should be presented in a transit context, nor to what extent the unique affordances of transit environments (e.g. the social presence of others) might influence passenger perception of virtual display layouts. Using a simulated VR passenger airplane environment, we evaluated three different AR-driven virtual display configurations (Horizontal, Vertical, and Focus main display with smaller secondary windows) at two different depths, exploring their usability, user preferences, and the underlying factors that influenced those preferences. We found that the perception of invading other’s personal space significantly influenced preferred layouts in transit contexts. Based on our findings, we reflect on the unique challenges posed by passenger contexts, provide recommendations regarding virtual display layout in the confined airplane environment, and expand on the significant benefits that AR offers over physical displays in said environments.

VR users and bystanders must sometimes interact, but our understanding of these interactions - their purpose, how they are accomplished, attitudes toward them, and where they break down - is limited. This current gap inhibits research into managing or supporting these interactions, and preventing unwanted or abusive activity. We present the results of the first survey (N=100) that investigates stories of actual emergent in-the-wild interactions between VR users and bystanders. Our analysis indicates VR user and bystander interactions can be categorised into one of three categories: coexisting, demoing, and interrupting. We highlight common interaction patterns and impediments encountered during these interactions. Bystanders play an important role in moderating the VR user’s experience, for example intervening to save the VR user from potential harm. However, our stories also suggest that the occlusive nature of VR introduces the potential for bystanders to exploit the vulnerable state of the VR user; and for the VR user to exploit the bystander for enhanced immersion, introducing significant ethical concerns.

This paper explores how acoustically transparent auditory headsets can improve TV viewing by intermixing headset and TV audio, facilitating personal, private auditory enhancements and augmentations of TV content whilst minimizing occlusion of the sounds of reality. We evaluate the impact of synchronously mirroring select audio channels from the 5.1 mix (dialogue, environmental sounds, and the full mix), and selectively augmenting TV viewing with additional speech (e.g. Audio Description, Directors Commentary, and Alternate Language). For TV content, auditory headsets enable better spatialization and more immersive, enjoyable viewing; the intermixing of TV and headset audio creates unique listening experiences; and private augmentations offer new ways to (re)watch content with others. Finally, we reflect on how these headsets might facilitate more immersive augmented TV viewing experiences within reach of consumers.

Virtual reality (VR) headsets allow wearers to escape their physical surroundings, immersing themselves in a virtual world. Although escape may not be realistic or acceptable in many everyday situations, air travel is one context where early adoption of VR could be very attractive. While travelling, passengers are seated in restricted spaces for long durations, reliant on limited seat-back displays or mobile devices. This paper explores the social acceptability and usability of VR for in-flight entertainment. In an initial survey, we captured respondents' attitudes towards the social acceptability of VR headsets during air travel. Based on the survey results, we developed a VR in-flight entertainment prototype and evaluated this in a focus group study. Our results discuss methods for improving the acceptability of VR in-flight, including using mixed reality to help users transition between virtual and physical environments and supporting interruption from other co-located people.

Acoustic levitation enables a radical new type of human-computer interface composed of small levitating objects. For the first time, we investigate the selection of such objects, an important part of interaction with a levitating object display. We present Point-and-Shake, a mid-air pointing interaction for selecting levitating objects, with feedback given through object movement. We describe the implementation of this technique and present two user studies that evaluate it. The first study found that users could accurately (96%) and quickly (4.1s) select objects by pointing at them. The second study found that users were able to accurately (95%) and quickly (3s) select occluded objects. These results show that Point-and-Shake is an effective way of initiating interaction with levitating object displays.

Room-scale Virtual Reality (VR) has become an affordable consumer reality, with applications ranging from entertainment to productivity. However, the limited physical space available for room-scale VR in the typical home or office environment poses a significant problem. To solve this, physical spaces can be extended by amplifying the mapping of physical to virtual movement (translational gain). Although amplified movement has been used since the earliest days of VR, little is known about how it influences reach-based interactions with virtual objects, now a standard feature of consumer VR. Consequently, this paper explores the picking and placing of virtual objects in VR for the first time, with translational gains of between 1x (a one-to-one mapping of a 3.5m*3.5m virtual space to the same sized physical space) and 3x (10.5m*10.5m virtual mapped to 3.5m*3.5m physical). Results show that reaching accuracy is maintained for up to 2x gain, however going beyond this diminishes accuracy and increases simulator sickness and perceived workload. We suggest gain levels of 1.5x to 1.75x can be utilized without compromising the usability of a VR task, significantly expanding the bounds of interactive room-scale VR.

Public evaluations are popular because some research questions can only be answered by turning "to the wild." Different approaches place experimenters in different roles during deployment, which has implications for the kinds of data that can be collected and the potential bias introduced by the experimenter. This paper expands our understanding of how experimenter roles impact public evaluations and provides an empirical basis to consider different evaluation approaches. We completed an evaluation of a playful gesture-controlled display not to understand interaction at the display but to compare different evaluation approaches. The conditions placed the experimenter in three roles, steward observer, overt observer, and covert observer, to measure the effect of experimenter presence and analyse the strengths and weaknesses of each approach.

We demonstrate a technique for rendering textured haptic surfaces in mid-air, using an ultrasound haptic display. Our technique renders tessellated 3D `haptic' shapes with different waveform properties, creating surfaces with distinct perceptions.

This one-day workshop explores how playful interaction can be used to develop technologies for public spaces and create temporal experiences.

Acoustic levitation enables new types of human-computer interface, where the content that users interact with is made up from small objects held in mid-air. We show that acoustically-levitated objects can form mid-air widgets that respond to interaction. Users can interact with them using in-air hand gestures. Sound and widget movement are used as feedback about the interaction.

Spherical displays present compelling opportunities for interaction in public spaces. However, there is little research into how touch interaction should control a spherical surface or how these displays are used in real world settings. This paper presents an in the wild deployment of an application for a spherical display called GlobalFestival that utilises two different touch interaction techniques. The first version of the application allows users to spin and tilt content on the display, while the second version only allows spinning the content. During the 4-day deployment, we collected overhead video data and on-display interaction logs. The analysis brings together quantitative and qualitative methods to understand how users approach and move around the display, how on screen interaction compares in the two versions of the application, and how the display supports social interaction given its novel form factor.

Interactive digital technologies pervade our shared spaces in personal, mobile, infrastructural and other embedded forms. These changes challenge the ways we understand and investigate the relationships between people, computing and settings. Responding to this situation—where ubiquitous computing is not only personal but also public, and where digital interactions may happen anywhere — this special issue explores how HCI research can use the strengths of an intersection of theory, practice and innovation in order to best address this conjunction of interactive technologies, public spaces and people interacting with or within both. \n \nWith this shift to interaction happening in public spaces, people can no longer be seen as just ‘users’ but have to be understood as acting assemblages of bodies and technologies in the space they inhabit. This shift highlights the need to understand users in every setting—including those at desks and at work—as socially and culturally situated humans with agency. While this is not a new research development, this special issue speculates on and discusses how the shift to ‘everywhere interactions’ makes it important for research in human–computer interaction to reach beyond existing conventions. With this work comes a need to understand the interacting human as a situated body that is at any moment also a possible spectacle: as a body, a human and a user who engages with technology in response to the situation while also being a ‘performance’ for others to witness. Understanding people as actors in their context allows us to regard every user as a ‘performing body’ and a ‘performing subject’, and it enables us to analyse the performative aspects of interaction in many other situations than those where we design for actually staged performances in a defined performance space or stage. In this sense, ‘performative interaction’ is both concerned with technologies for on-stage performers using technologies as part of artistic expression, and an analytical frame for understanding every situation in which people engage with technologies (in public space). The question becomes: where and in which situations is this analytical frame relevant and useful?

The user experience of performing gesture-based interactions in public spaces is highly dependent on context, where users must decide which gestures they will use and how they will perform them. In order to complete a realistic evaluation of how users make these decisions, the evaluation of such user experiences must be completed "in the wild." Furthermore, studies need to be completed within different cultural contexts in order to understand how users might adopt gesture differently in different cultures. This paper presents such a study using a mobile gesture-based game, where users in the UK and India interacted with this game over the span of 6 days. The results of this study demonstrate similarities between gesture use in these divergent cultural settings, illustrate factors that influence gesture acceptance such as perceived size of movement and perceived accuracy, and provide insights into the interaction design of mobile gestures when gestures are distributed across the body.

More and more interactive artifacts are used in public on an everyday basis, and metaphors from performance and theatre studies find their way into research on these interfaces, addressing how interaction with technology can be understood in a performative sense. Through theoretical discussions as well as practical design activities and building on the assumption that every human action in public space has a performative aspect, this workshop seeks to explore performative interaction as it occurs in real world public settings with interactive technologies. The purpose of the workshop is to make prototyping experiments that enable participants to explore select themes and questions relevant to everyday or staged performativity, e.g. the design of performative technologies, the evaluation of user experience, the importance of spectator and performer roles, and the social acceptability of performative actions in public spaces.

Reminder systems are a specific range of technologies for care at home that can deliver notifications or reminders (such as 'take your medication') to assist with daily living. How to best deliver these reminders is an interesting research challenge. Today's technologies have the potential to deliver the notifications in a range of output modalities. The delivery methods can be selected both by the system (depending on what devices are available in the home) and on the users' needs, capabilities and preferences. This paper describes a user-centred approach to the design of multimodal output for reminders in the home. In a focus group study (N=15), this paper explores how six output modalities could be used to present reminders in a home setting. The results demonstrate user requirements that can be incorporated into the early phases of the design of a multimodal reminder system.

This paper presents a study that explores the issues of mobile multimodal interactions while on the move in the real world. Because multimodal interfaces allow new kinds of eyes and hands free interactions, usability issues while moving through different public spaces becomes an important issue in user experience and acceptance of multimodal interaction. This study focuses on these issues by deploying an RSS reader that participants used during their daily commute every day for one week. The system allows users on the move to access news feeds eyes free through head- phones playing audio and speech and hands free through wearable sensors attached to the wrists. The results showed participants were able to interact with the system on the move and became more comfortable performing these interactions as the study progressed. Users were also far more comfortable gesturing on the street than on public transport, which was reflected in the number of interactions and the perceived social acceptability of the gestures in different contexts.

Gesture-based mobile interfaces require users to change the way they use technology in public settings. Since mobile phones are part of our public appearance, designers must integrate gestures that users perceive as acceptable for public use. This topic has received little attention in the literature so far. The studies described in this paper begin to look at the social acceptability of a set of gestures with respect to location and audience in order to investigate possible ways of measuring social acceptability. The results of the initial survey showed that location and audience had a significant impact on a user's willingness to perform gestures. These results were further examined through a user study where participants were asked to perform gestures in different settings (including a busy street) over repeated trials. The results of this work provide gesture design recommendations as well as social acceptability evaluation guidelines.

Gesture based interfaces provide a new way for us to interact with mobile devices, but also require us to make new decisions about how we feel about this new technology and which gestures we decide are usable and appropriate. These decisions are based on the social and public settings where these devices are used on a daily basis. Our ideas about which gestures are socially acceptable or not are an important factor in whether or not these gestures will be adopted. The ways in which users evaluate social acceptability is not only highly variable, but with drastically different results amongst different users. These differences are not dependant on factors such as age, gender, occupation, geographic location, or previous technology usage. Future work into the social acceptability perceptions of users will focus on personality traits as a new way of understanding how social acceptability is determined.