Camera-based facial-gesture interfaces offer hands-free access for people with motor impairments (PwM), yet most recognition models are trained on able-bodied data and implicitly assume normative motor control and proprioception. We conducted a mixed-methods empirical study of 37 above-neck gestures performed by 11 PwM and 11 non-impaired participants. Results reveal systematic mismatches between user intention and model recognition in the PwM group, stemming from diverse patterns of body perception and control and leading to allocative harms. These mismatches concentrated in low-amplitude, asymmetric, and directional gestures. Building on these findings, we introduce FairGesture, a diagnostic auditing method for quantifying and interpreting such mismatches. FairGesture combines (1) the Perception Gap metric, (2) trajectory-based motion analysis, and (3) an analysis of user sensorimotor feedback, exploring the reasons behind these mismatches. The work reframes accuracy in gesture recognition as a problem of sensorimotor alignment, advancing user-centred evaluation and inclusive model design.

The design of digital technologies for older adults is often premised on deficit models of ageing that position older people as a homogenous group and as passive users of technology, with an overwhelming focus on meeting practical needs in older age. In response, a growing number of scholars in HCI and Science and Technology Studies (STS) are engaging with processes of co-design that situate older adults as experts in their own lives and as central to the design process. These scholars highlight how an essential first phase of co-design is understanding and foregrounding the lifeworlds, experiences and expertise of older adults. This paper responds to these calls, alongside the lack of consideration of minoritised older adults in co-design. It draws on the empirical findings from the first phase of the Connecting Through Culture As We Age project, which places twenty minoritised older adults who identify as disabled, and/or racially and/or socio-economically minoritised, at the centre of a digital innovation process. Through a case study approach, we focus on two of the minoritised older adults involved, to demonstrate the value of bringing together participatory methods with an interdisciplinary lifecourse lens. We highlight the power of this approach for understanding minoritised older adults' relationships with technology, as shaped by experiences across the lifecourse, for building relationships, and ensuring their agency and voice underpin the co-design process.

Personality characteristics can affect how much presence an individual experiences in virtual reality, and researchers have explored how it may be possible to prime users to increase their sense of presence. A personality characteristic that has yet to be explored in the VR literature is imaginative suggestibility, the ability of an individual to successfully experience an imaginary scenario as if it were real. In this paper, we explore how suggestibility and priming affect presence when consulting an ancient oracle in VR as part of an educational experience – a common VR application. We show for the first time how imaginative suggestibility is a major factor which affects presence and emotions experienced in VR, while priming cues have no effect on participants’ (n=128) user experience, contrasting results from prior work. We consider the impacts of these findings for VR design and provide guidelines based on our results.

Whilst the use of smart home systems has shown promise in recent years supporting older people's activities at home, there is more evidence needed to understand how these systems impact the type and the amount of shared care in the home. It is important to understand care recipients and caregivers' labour is changed with the introduction of a smart home system to efficiently and effectively support an increasingly aging population with technology. Five older households (8 participants) were interviewed before, immediately after and three months after receiving a Smart Home Health System (SHHS). We provide an identification and documentation of critical incidents and barriers that increased inter-household care work and prevented the SHHS from being successfully accepted within homes. Findings are framed within the growing body of work on smart homes for health and care, and we provide implications for designing future systems for shared home care needs.

Although the use of voice assistants to support older adults at home shows promise, little is known about how the next generation of these devices, which also include displays, can support health and care needs. This question has become more important during COVID-19, when issues of social isolation for older adults have been exacerbated. During social distancing measures in the UK, eleven older adult households (16 participants) were interviewed before receiving an Amazon Echo Show, shortly after receiving it, and after three months of use. We identify ways in which this multi-modal device is used by people in social isolation to support social, care, and information needs in the home. We frame these findings within the growing research area of smart homes for health and care, and provide implications for the adoption, use and acceptance of these devices to support aging in place together.

We evaluate AR for Plant maintenance by measuring how a prototype guidance system, tested under representative conditions, impacts performance. We are motivated to determine the cost-benefit of interactive guidance for hazardous, repetitive tasks and we observe an improvement of 21% efficiency, 50% accuracy and 19% reduced task load. AR has already been shown to deliver improvements in task performance, however, there is limited research exploring the integration of AR into complete task routines which presents a barrier to adoption. We apply mixed reality guidance via two within-group experiments. We measure efficiency and accuracy over a complete routine conducted under simulated conditions. Results compare AR versus Static and AR versus Adaptive. We conclude AR is best suited to demanding spatial translation and completion under pressure. We suggest AR offers potential in similar routines and propose further work to integrate in a live setting.

This paper presents a novel mobile serious game, "Space Vision", which uses a hidden-object mechanic with fiducial marker detection to gamify a clinical test of visual acuity - a key marker of childhood eye disease. For Space Vision to become a credible clinical tool that can facilitate the screening and home-monitoring of children's visual acuity, it must be able to sustain player engagement over the extended durations required to detect vision abnormalities. Hence, we pay particular attention to developing effective game characters - a crucial aspect of children's game design. Using an early prototype with 13 school children (aged 5-6 years), we investigate player experiences through a series of evaluation sessions, involving a single one-to-one observational playtest, semi-structured interview, and ideation activity with each child. Thematic analysis of our session video recordings, written observations, and ideation artefacts, found that future game iterations must: increase resonance between players and game characters by providing aesthetic and behavioural customisation, embrace more anthropomorphic styling, better imbue narratives pertaining to children's life scripts, and feature fantasy character powers as a form of self-expression. Meanwhile, greater physical device support and digital incentivisation of body posture and head position are key to improving the reliability of the visual acuity measurement.

Stairlifts are a widely-used technology in the home that help people with mobility issues to go up and down stairs. However, it is unclear how stairlifts are experienced by all household members and what this understanding implies for home healthcare technologies. We investigated the impact of stairlift installations on older adults' households in the UK through a qualitative study investigating the lived experience of the adoption and acceptance of this technology. Interviews and focus groups with primary users, household residents and service providers showed how the wider household identify misalignments between simplified stairlift installation models from service providers and describe a more complex, nuanced emotional journey which involves decision making, conflict and trauma and catharsis and independence. Findings provide transferrable outcomes for the smart home domain by highlighting the multi-resident home, the emotional intrusiveness of home healthcare technologies and the diversity that comes with providing care, unique to every household.

For 'looked-after' and adopted children, physical objects are often the only remaining link to their pasts; a portal to stories of former families, homes, and events. The act of reminiscence, known as 'life story work', can help children to process their pasts and overcome trauma. This paper describes the user-centred redesign of Trove, a digital and physical memory box for storing and curating stories about precious objects. We describe our redesign process, synthesising the insights from previous Trove evaluations with looked-after and adopted children, and three re-design workshops with 4 looked-after children at a therapeutic residential school. Our findings advocate for prioritisation of Trove's digital and physical security, the sustainability of its companionship, and the provision of multimedia storytelling to encourage the construction of identity narratives. Inspired by this, we present and discuss the redeveloped Trove, before analysing our participatory design approach with these complex and under-represented groups.

For looked after and adopted children, physical objects are often the only remaining link to their past; a portal to stories of birth families, former homes, and significant people. Yet, often these stories can be littered with traumatic events preventing them from moving forward with their lives. Through reminiscence of these stories and attempting to develop narratives of past events, known as 'life story work', we can help children to emotionally process their past. This paper introduces, trove, a digital and physical memory box for storing and curating stories about precious objects. trove creates a safe space for keeping these objects in transient environments and constructing life story narratives.

Virtual Reality nonfiction (VRNF) is an emerging form of immersive media experience created for consumption using panoramic "Virtual Reality" headsets. VRNF promises nonfiction content producers the potential to create new ways for audiences to experience "the real"; allowing viewers to transition from passive spectators to active participants. Our current project is exploring VRNF through a series of ethnographic and experimental studies. In order to document the content available, we embarked on an analysis of VR documentaries produced to date. In this paper, we present an analysis of a representative sample of 150 VRNF titles released between 2012-2018. We identify and quantify 64 characteristics of the medium over this period, discuss how producers are exploiting the affordances of VR, and shed light on new audience roles. Our findings provide insight into the current state of the art in VRNF and provide a digital resource for other researchers in this area.

This study examined whether the high level of immersion provided by HMDs encourages participants to synchronise their attention during viewing. 39 participants watched the 360° documentary “Clouds Over Sidra” using either a HMD or via a flat screen tablet display. We found that the HMD group showed significantly greater overall ISC did the tablet group and that this effect was strongest during transition between scenes.

This paper presents the concept of Resonant Bits, an interaction technique for encouraging engaging, slow and skilful interaction with tangible, mobile and ubiquitous devices. The technique is based on the resonant excitation of harmonic oscillators and allows the exploration of a number of novel types of tangible interaction including: ideomotor control, where subliminal micro-movements accumulate over time to produce a visible outcome; indirect tangible interaction, where a number of devices can be controlled simultaneously through an intermediary object such as a table; and slow interaction, with meditative and repetitive gestures being used for control. The Resonant Bits concept is tested as an interaction method in a study where participants resonate with virtual pendulums on a mobile device. The Harmonic Tuner, a resonance-based music player, is presented as a simple example of using resonant bits. Overall, our ambition in proposing the Resonant Bits concept is to promote skilful, engaging and ultimately rewarding forms of interaction with tangible devices that takes time and patience to learn and master.

Community activist groups typically rely on core groups of highly motivated members. In this paper we consider how crowdsourcing strategies can be used to supplement the activities of pro-environmental community activists, thus increasing the scalability of their campaigns. We focus on mobile data collection applications and strategies that can be used to engage casual participants in pro-environmental data collection. We report the results of a study that used both quantitative and qualitative methods to investigate the impact of different motivational factors and strategies, including both intrinsic and extrinsic motivators. The study compared and provides empirical evidence for the effectiveness of two extrinsic motivation strategies, pointification - a subset of gamification - and financial incentives. Prior environmental interest is also assessed as an intrinsic motivation factor. In contrast to previous HCI research on pro-environmental technology, much of which has focused on individual behavior change, this paper offers new insights and recommendations on the design of systems that target groups and communities.

Mobile devices are increasingly providing novel ways for users to engage with the spaces around them. However, there are few systematic studies of enhancing spatial ability with mobile devices, and applications such as turn-by-turn navigation systems have even been associated with a decline in spatial skills. In this paper we present a study based on the 1971 Shepard-Metzler mental rotation test but performed on a mobile-phone handset and a tablet PC. Our study extends the original experiment with the incorporation of touch and tilt interaction techniques, in order to determine if these affect the use and acquisition of spatial skills. Results suggest that the task is performed faster, and with no significant difference in accuracy, when participants rely on mental abilities rather than interaction techniques to perform 3D rotations. We also find significant differences between tablet and phone handset platforms under interactive conditions. We conclude that applications on mobile devices could be designed to enhance rather than erode spatial skills, by supporting the use of imagination to align real and virtual content.

Location-aware systems have traditionally left mobility to the user through carrying, supporting and manipulating the device itself. This design choice has limited the scale and style of device to corresponding weight and form constraints. This paper presents a project introducing school children to location aware systems. We observed that it is hard to notice, physically grasp and simultaneously share these small personal devices in groups. These behaviours are partly grounded in the physical device design, but also in the location awareness model itself, which provides information 'right here' while the children are looking around and about them. These observations lead us to suggest the alternative model of pointing at locations so that they can be noticed and experienced by groups in public places. We further build this location model into the device itself by introducing actuated components from robotics to make a location-aware device called 'Limbot' that can be physically pointed. A preliminary study of the Limbot with the school children indicates rich sharing behaviours, but that user control of actuation at all points is critical to the ultimate success of our approach, and further exploration of our location model is required.

There are two major influences on human visual attention: bottom-up and top-down processing. Bottom-up processing is the automatic direction of gaze to lively or colourful objects as determined by low-level vision. In contrast, top-down processing is consciously directed attention in the pursuit of predetermined goals or tasks. Previous work in perception-based rendering has exploited bottom-up visual attention to control detail (and therefore time) spent on rendering parts of a scene. In this paper, we demonstrate the principle of Inattentional Blindness, a major side effect of top-down processing, where portions of the scene unrelated to the specific task go unnoticed. In our experiment, we showed a pair of animations rendered at different quality levels to 160 subjects, and then asked if they noticed a change. We instructed half the subjects to simply watch our animation, while the other half performed a specific task during the animation.When parts of the scene, outside the focus of this task, were rendered at lower quality, almost none of the task-directed subjects noticed, whereas the difference was clearly visible to the control group. Our results clearly show that top-down visual processing can be exploited to reduce rendering times substantially without compromising perceived visual quality in interactive tasks.