This scoping review examines the past decade of research at the intersection of democracy, technology and design. Analysing 170 articles across Scopus, the ACM Digital Library, and the DRS Digital Library, we investigate how this research relates to democracy and how democratic values are conceptualised and enacted through interactive systems. We identify four dominant orientations: technology as democratic repair, as risk, as co-constitutive of democratic practices, and as embedded in everyday collective action and lived practices. Across these, we reveal a persistent misalignment: while democratic values are frequently invoked, much of the work reduces democracy to technical or procedural problems, prioritising optimisation over power, relationality, and lived practice. As a result, key dimensions such as collective agency, structural inequalities, and infrastructural conditions remain under-addressed, offering novel opportunities for HCI research. We argue that democratic technology design should advance better alignment fostering responsibility, participation, equity, and transparency in sociotechnical systems.

The science and technology world is stuck in an unresolved debate: can technologies ever be conscious? While this question dominates discussions in neuropsychology and cognitive science, it is ultimately unproductive for Human-Computer Interaction (HCI). As users perceive a level of consciousness in commercially available systems, there is a need to understand the factors that lead to a perception of consciousness so that we account for consciousness in designing interactive systems. To that end, we systematically develop the Precursors of Perceived Consciousness in Interactive Systems Scale—a validated instrument for quantifying the design qualities that contribute to perceived consciousness in a technology. Through reporting on a structured scale development process, we show how the PreCoS enables studies of technologies potentially perceived as conscious. PreCoS is the first step towards the systematic study and design of systems which responsibly integrate perceived consciousness: fostering positive, engaging experiences while recognising and mitigating ethical risks such as overtrust, bias, or psychological discomfort.

Playing cards have long been a central feature in board games, despite their physical limitations, such as fragility, and repetitive content. Yet, while HCI research increasingly explores augmented board games, interactive playing cards remain underexplored. In this work, we investigate the use of e-paper displays as interactive playing cards. Based on a formative study with eight game designers, we designed and implemented InkStack—a prototype consisting of e-paper cards, a dedicated programmer, and a web application for card customisation. We then evaluated InkStack in a within-subject study with n = 20 participants, comparing its use across four board game mechanics against traditional paper cards and a smartphone. Results show that InkStack is preferred for more complex mechanics, whereas paper and smartphones are sufficient for simpler tasks. The findings also highlight how customisation and versatility can enhance gameplay and enable novel forms of interaction.

The ambiguity surrounding ‘creepy technology’ in HCI poses significant challenges, as its interpretation varies considerably based on research focus. While it is commonly linked to the appearance of robots and concerns about data privacy and security, it is increasingly associated with functionality, unpredictability, and appropriateness of system behaviour and interaction. Clarifying this ambiguity is vital for designers, as it directly affects user experience and trust in technology. To address this, we undertook a systematic review of 115 papers, identifying key themes related to design choices and contextual elements of creepiness. Based on this review, we developed the Creepiness Framework, which comprises two main components: the Structure of Creepiness and Felt Creepiness. The framework clarifies the dynamics of creepy technology. Additionally, we derive design-relevant insights into creepiness features that can guide the development of technologies that are more predictable and less likely to evoke unintended feelings of creepiness.

While technology is widely recognised as a tool to enhance wellbeing, there is no clear consensus on the best practices for design. Persuasive strategies, such as nudging, are often seen as effective but raise ethical concerns. Reflection-based approaches offer a potential alternative. However, a clear understanding of the balance between these strategies is crucial for designing effective and ethically sound wellbeing technologies. We conducted two studies with a total of n = 163 participants comparing nudging and reflection techniques using contrasting prototypes of fitness wearables. We verified that the prototypes represented key nudging and reflection strategies through expert feedback. Our mixed-methods inquiry shows that certain nudging strategies are perceived as more malicious and more likely to provoke rumination, i.e., negative thought cycles, compared to other wellbeing strategies. We contribute insights to inform design decisions for wellbeing technologies, balancing effectiveness with ethical considerations.

Figure 1: In this study, we explore the potential of mobile desks to provide flexible and adaptive workspace solutions for promoting healthier office habits.We designed a mobile desk capable of autonomous movement and evaluated it in three configurations: manual control using a crank, control via a physical control panel, and fully automated adaptive operation.

In the context of rising sedentary lifestyles, this paper investigates the efficacy of "Situated Artifacts"in promoting physical activity. We designed two artifacts that display users' physical activity data within their homes - one physical and one digital. We conducted a 9-week, counterbalanced, within-subject field study with N = 24 participants to assess the impact of these artifacts on physical activity, reflection, and motivation. We collected quantitative data on physical activity and administered daily and weekly questionnaires, employing individual Likert items and standardized instruments, as well as conducted interviews post-prototype usage. Our findings indicate that while both artifacts act as reminders for physical activity, the physical artifact was superior in terms of user engagement. The study revealed that this can be attributed to the higher perceived presence and, thereby, enhanced social interaction, which acts as a motivational source for activity. In this sense, situated artifacts gently nudge toward sustainable health behavior change.

Figure 1: Screenshots from PuppetVR: (a) Bird's-eye view of the virtual environment.(b) Close-up of a recorded layered interaction of three of the puppets.(c) In-world user interface panels with controls and a task list with onboarding instructions.

Recent HCI research emphasizes the importance of considering children's care ecosystems in the design of systems that support their well-being, including not only family, but also extended support networks, such as teachers and therapists.While this approach offers opportunities for care and collaboration, it also introduces challenges such as recruitment, appropriate methods, power dynamics, navigating diverse perspectives, and ethical considerations.This workshop 1 seeks to bring together IDC researchers and practitioners to discuss opportunities, challenges, methods, and tools towards a research agenda for designing technologies for and with children and their care ecosystems.It also aims to foster collaboration and strengthen the community by facilitating networking among researchers towards conducting multi-stakeholder research.

Most studies of Personal Informatics (PI) focus on the holistic experience of self-tracking or how users relate to self-tracking goals. Recently, new tracker metrics became available in commercial systems, e.g. stress scores or body battery. Hence, more attention should be devoted to what users track and how they understand metrics produced by their trackers. Charting the evolution of metrics in PI can enable building systems that better support well-being. To this end, we interviewed n = 25 fitness tracker users to discover what metrics are most important to them, how they understand the metrics, and how they formulate their goals with respect to the metrics. We found that users created a metric ecology which they adjusted to their life circumstances, reformulating their goals. We identified key issues in understanding metrics which bear the risk of misuse. We contribute recommendations for future PI systems as self-tracking metrics increase in complexity.

Dark patterns are deceptive strategies that recent work in humancomputer interaction (HCI) has captured throughout digital domains, including social networking sites (SNSs).While research has identified difficulties among people to recognise dark patterns effectively, few studies consider vulnerable populations and their experience in this regard, including people with attention deficit hyperactivity disorder (ADHD), who may be especially susceptible to attention-grabbing tricks.Based on an interactive web study with 135 participants, we investigate SNS users' ability to recognise and avoid dark patterns by comparing results from participants with and without ADHD.In line with prior work, we noticed overall low recognition of dark patterns with no significant differences between the two groups.Yet, ADHD individuals were able to avoid specific dark patterns more often.Our results advance previous work by understanding dark patterns in a realistic environment and offer insights into their effect on vulnerable populations.

Navigating emotional conflicts within relationships can be challenging. People often struggle to express their emotions during a conflict, which can lead to misunderstandings and unresolved feelings. To facilitate deeper emotional expression, we developed TogetherReflect, a multi-user Virtual Reality (VR) experience designed for couples. Partners first draw their emotions related to a shared conflict in VR, allowing for individual expression and self-reflection. They then invite each other into their drawings to discuss their feelings, before drawing together on a shared canvas to reaffirm their love and commitment. Throughout this process, TogetherReflect provides prompts and guidance, aiming to foster self-reflection and communication skills. We exploratory evaluated the experience with 10 couples (n=20). Our findings indicate that TogetherReflect deepens personal emotional insights, fosters mutual understanding, and strengthens relational bonds. We highlight the potential of guided VR experiences to transform conflict resolution in intimate relationships and offer design considerations for future development.

Recent technological advances popularized the use of image generation among the general public. Crafting effective prompts can, however, be difficult for novice users. To tackle this challenge, we developed PromptMap, a new interaction style for text-to-image AI that allows users to freely explore a vast collection of synthetic prompts through a map-like view with semantic zoom. PromptMap groups images visually by their semantic similarity, allowing users to discover relevant examples. We evaluated PromptMap in a between-subject online study ($n=60$) and a qualitative within-subject study ($n=12$). We found that PromptMap supported users in crafting prompts by providing them with examples. We also demonstrated the feasibility of using LLMs to create vast example collections. Our work contributes a new interaction style that supports users unfamiliar with prompting in achieving a satisfactory image output.

While Personal Informatics (PI) tools utilise data visualisations to communicate behaviour, users often struggle to make sense of their data and translate it to actionable insights. Conversational Agents (CAs) offer potential for improved access to PI data, yet their role in PI tools remains under-explored. We conducted a two-week user study with journals, interviews and logging with n = 36 participants using a novel commercial fitness tracker with an embedded CA. We identified the give and take principle as essential for meaningful sensemaking with a CA—a dynamic resulting in more effective interactions given users’ inputs ( give ) are met with prompts that are sufficiently specific and built upon prior data engagement ( take ). A critical point was how users perceived the CA during their initial interactions, with first impressions often determining further engagement. We contribute insights into how CAs can support or hinder the PI experience, offering implications for future PI system designs.

Children with attention deficit hyperactivity disorder (ADHD) and their caregivers face daily challenges which can adversely affect their well-being, especially regarding communication within their care ecosystems, comprising family, friends, educators, and therapists. To foster communication among children and their care ecosystem and support their well-being, we created REMEMO, a mobile app that was iteratively designed and evaluated by actively involving ADHD children and their caregivers. REMEMO supports both individual and collaborative use, offering tailored features for different user groups: children, parents, or therapists and educators. Its primary function is to enable users to record their experiences and emotions and choose whether to share these with other members of the care ecosystem. We deployed REMEMO in a multi-week field study with five groups encompassing ADHD children (total participants n=18). Our analysis showed that REMEMO can support emotional expression, regulation, reflection, transparent and affectionate communication, as well as therapeutic practices, addressing needs of both ADHD children and their caregivers. Our findings also highlight the critical role of mutual understanding regarding technology use and contextual challenges in shaping usage patterns. We discuss opportunities and challenges in designing technologies that cater to the varying needs of different stakeholders of ADHD children's care ecosystems and engage in critical reflection regarding evaluating technologies with vulnerable populations, such as families of ADHD children.

Building tangible interfaces or data physicalizations is a resource-intensive endeavour. There is a need for rapid means to prototype tangibles in order to facilitate research and design. To this end, we designed ProtoBricks: a research toolkit that uses capacitive bricks to facilitate rapid prototyping for tangible interfaces. Utilizing toy bricks that do not contain electronics, ProtoBricks can record brick position and color. Specialized knowledge is not required to build our system as it uses widely available components and 3D printing. We contribute the full software and hardware specification of the toolkit. We evaluate the utility of the toolkit by reporting on past use cases and prototyping workshops. We show that the toolkit facilitates creativity and effectively supports prototyping. ProtoBricks lowers the entry threshold for experimenting with tangible interfaces and enables researchers and designers to focus on the interaction with their prototype, delegating implementation to the toolkit.

Decision-making aided by Artificial Intelligence in high-stakes domains such as law enforcement must be informed and accountable. Thus, designing explainable artificial intelligence (XAI) for such settings is a key social concern. Yet, explanations are often misunderstood by end-users due to being overly technical or abstract. To address this, our study engaged with police employees in the Netherlands, who are users of a text classifier. We found that for them, usability and usefulness are of great importance in explanation design, whereas interpretability and understandability are less valued. Further, our work reports on how design elements included in machine learning model explanations are interpreted. Drawing from these insights, we contribute recommendations that guide XAI system designers to cater to the specific needs of specialized users in high-stakes domains and suggest design considerations for machine learning model explanations aimed at domain experts.

Negative emotions such as sadness or anger are often seen as something to be avoided. However, recognising, processing and regulating challenging emotional experiences can facilitate personal growth and is essential for long-term well-being. To support people in regulating and reflecting on negative emotions, we designed MoodShaper — a VR experience where participants autonomously create a virtual environment combined with emotion regulation (ER) interventions. Our system included three different interventions designed based on interviews with psychotherapists. We evaluated MoodShaper in a mixed-method between-subject study with n = 60 participants. Participants experienced one of the three ER interventions, allowing them to manipulate visual representations of negative emotions through externalisation, seclusion, or appreciation. We found that MoodShaper significantly increased positive affect while decreasing difficulties in ER and negative affect. Our work demonstrates how VR can provide technology-mediated support to reflect on, engage with and manage negative emotions. We contribute insights for future VR systems which support ER for challenging situations.

Many technologies for ADHD children and their caregivers focus on symptom management rather than overall well-being, often without involving them as technology co-designers and co-users. To explore how to design systems that integrate into their home and routines, we contribute the iterative design of MoodGems, a situated, modular, and portable set of physical displays, that allows children to record and share their data with their families. We conducted an online formative evaluation (n = 22) with ADHD children, parents, therapists, and HCI experts. Our work demonstrates the potential of technologies affording both individual and joint tracking to allow children to navigate and reflect on their experiences and emotions, and support family communication and children’s autonomy. The evaluation also uncovered necessary refinements in the system’s design. We contribute design insights towards technologies that empower ADHD children and integrate into their homes, and discuss therapists’ role in technologies that address ADHD families’ lived experiences.

Many interactive systems that support tabletop games either augment the experience with additional elements or transform game components into digital counterparts, e.g., using mixed reality. However, as many users prefer tangible game elements, digital augmentations can disrupt the immersion they seek to enhance, often due to the complexity of the hardware used. Responding to this challenge, we designed a screenless interactive tabletop system with capacitive sensing. The system is suitable for novice players and provides automatic score-keeping. Our method eliminates the need for external sensors and retains all original game pieces intact. We evaluated our system in a study with a forest planting game (n = 20). Gameplay with our system exhibited shorter turn duration, and participants adopted more effective strategies than in traditional gameplay. These results underscore the potential of screenless interactive tabletops to amplify the gaming experience without causing distractions.

Current research in Mixed Reality (MR) presents a wide range of novel use cases for blending virtual elements with the real world. This yet-to-be-ubiquitous technology challenges how users currently work and interact with digital content. While offering many potential advantages, MR technologies introduce new security, safety, and privacy challenges. Thus, it is relevant to understand users’ apprehensions towards MR technologies, ranging from security concerns to social acceptance. To address this challenge, we present the Mixed Reality Concerns (MRC) Questionnaire, designed to assess users’ concerns towards MR artifacts and applications systematically. The development followed a structured process considering previous work, expert interviews, iterative refinements, and confirmatory tests to analytically validate the questionnaire. The MRC Questionnaire offers a new method of assessing users’ critical opinions to compare and assess novel MR artifacts and applications regarding security, privacy, social implications, and trust.

While fitness trackers generate and present quantitative data, past research suggests that users often conceptualise their wellbeing in qualitative terms. This discrepancy between numeric data and personal wellbeing perception may limit the effectiveness of personal informatics tools in encouraging meaningful engagement with one’s wellbeing. In this work, we aim to bridge the gap between raw numeric metrics and users’ qualitative perceptions of wellbeing. In an online survey with n = 273 participants, we used step data from fitness trackers and compared three presentation formats: standard charts, qualitative descriptions generated by an LLM (Large Language Model), and a combination of both. Our findings reveal that users experienced more reflection, focused attention and reward when presented with the generated qualitative data compared to the standard charts alone. Our work demonstrates how automatically generated data descriptions can effectively complement numeric fitness data, fostering a richer, more reflective engagement with personal wellbeing information.

Adolescence is a period of growth and exploration, marked by influential relationships with peers and parents. These relationships are essential for teenagers’ well-being, highlighting the need to support their interpersonal interactions. Emotional expression is key in resolving conflicts that can frequently arise. This paper investigates the potential of TeenWorlds, a Virtual Reality (VR) application, to facilitate emotional expression and shared understanding among teenagers and their peers and parents. In our study, teenagers, accompanied by either a peer or a parent (total n=42), used TeenWorlds to visually represent their emotions during a shared conflict, discuss them, and collaborate on a joint VR drawing. Our findings indicate that TeenWorlds can foster communication, reflection, and strengthen interpersonal relationships. However, notable differences were observed in interactions with peers versus parents. We contribute insights into designing VR systems that support reflective experiences and meaningful family interactions, ultimately enhancing the well-being of adolescents, parents, and families.

Photography has been pivotal in culture for decades and its importance has increased with the rise of digital technology. However, the exploration of picture taking within the Human-Computer Interaction (HCI) community does not seem to match its cultural and technological significance. Recognizing this discrepancy, we sought to understand areas of interest in photography as a conscious creative process. To address this issue, we performed a systematic literature review using the PRISMA methodology. From our research, we identified 62 pertinent papers spanning from 2005 to 2022. Our examination revealed six primary dimensions, further classified into study type, design goal, photo-taking style, device type, interaction style, and number of users. In-depth analysis showed the dominant role of exploratory and functional research, the balance between qualitative and quantitative methods, and a strong focus on smartphone cameras. Our review has highlighted significant gaps in the existing literature, offering valuable insights for future research on photo taking.

Allowing users of interactive systems to reflect on their task proficiency is often incidental. This is unfortunate, as communicating meaningful task-related proficiency feedback could improve users’ awareness of their abilities and their willingness to improve. To highlight the feasibility of this concept, we evaluated how different methods of readability feedback impacted users during a text production task. In general, our results showed that having access to readability feedback allowed participants to reflect on their task solving approach, facilitating the users’ understanding of their proficiency. Revision-based methods are less distracting for the user than continuous feedback methods, while still offering high efficacy. Further, feedback should be paired with a subtle form of gamification elements. We envision this reflection-oriented design to user proficiency to be applicable to a variety of interactive systems, allowing for an improved and engaging user experience.

Mastering skills which involve high dexterity, such as playing the piano, requires extensive guidance through personal teaching. Understanding how we can leverage data from sensor-based systems to improve the learning process, allows us to build interactive systems which effectively facilitate skill acquisition. To explore such possibilities, we developed EyePiano—a gaze-assisted tool for reflective piano playing. EyePiano guides the practice process of learning piano scores through analyzing the pianist’s gaze behavior. We based the design of EyePiano on requirements identified through interviews with piano teachers and a feasibility evaluation of gaze metrics. Our system illustrates that basic gaze metrics are sufficient to predict difficult regions for students. Thus, highlighting sections of the music piece which are particularly difficult for the pianist allows EyePiano to support piano rehearsals for students. Our work showcases the feasibility of using gaze data for reflective music education, enabling effective instrument practice.

While personal trackers can collect a vast amount of information about their users, the representation of such data has remained unchanged, with bar charts being the most dominant. However, to build systems that facilitate reflection and support well-being, it is crucial to explore alternative ways of representation. Thus, we designed VeatherReflect, a VR application that uses weather metaphors to illustrate tracker stress scores, aiming to encourage users to reflect on their stress data. In a pre-study, we mapped stress scores to weather states. We then compared VeatherReflect with a standard visualisation of stress data presented in VR. VeatherReflect increased participant engagement with personal data and stress awareness. Participants reported reflective insights for stress-reducing behaviour. We contribute findings on how virtual weather as a metaphor for stress can support reflection. We discuss design recommendations for VR applications aiming to facilitate a deeper understanding of complex personal data through engaging qualitative experiences.

Recent research has shown that users increasingly seek meaning in technologies and that eudaimonic user experience (UX) is part of everyday encounters with technology. Yet, to date, there is no validated means to assess eudaimonic properties in interactive artefacts. We conceptualised, developed and validated a six-item questionnaire for measuring eudaimonic properties of technologies—the Eudaimonic Technology Experience Scale (ETES). Our scale includes two factors, which describe what aspects of a eudaimonic experience can be supported by technology: eudaimonic goals and self-knowlege. We consulted work in Human-Computer Interaction (HCI), psychology and philosophy to gather an initial set of concepts that could contribute to eudaimonic UX. We then built the scale based on expert interviews and exploratory factor analysis and verified its quality in a number of tests (confirmatory factor analysis, reliability and validity checks). ETES provides a standardised tool for identifying eudaimonic qualities in interactive systems and allows for rapidly comparing prototypes.

Playing together is crucial to the unique and invaluable bond between grandparents and grandchildren. However, co-located interactions and play can be limited due to time, distance, or pandemic-related restrictions. To facilitate distributed play, we developed MagiBricks, a system comprised of 3D-printed smart toy bricks and baseplates that provide feedback regarding their placement. The familiarity and appeal of toy bricks to both older adults and children make them ideal for intergenerational play. We conducted a within-subjects study with six grandparent-grandchildren pairs. We compared the interactions and perceived connectedness of the pairs while playing over a distance with either i) MagiBricks or ii) identical regular toy bricks. We found that MagiBricks affected communication dynamics, role taking, nature of play, and perception of connectedness during playtime compared to regular bricks, and were unanimously preferred. We contribute design implications for future systems leveraging (smart) tangibles and fostering intergenerational connectedness.

The ever-increasing number of devices quantifying our lives offers a perspective of high awareness of one’s wellbeing, yet it remains a challenge for personal informatics (PI) to effectively support data-based reflection. Effective reflection is recognised as a key factor for PI technologies to foster wellbeing. Here, we investigate whether building tangible representations of health data can offer engaging and reflective experiences. We conducted a between-subjects study where n = 60 participants explored their immediate blood pressure data in relation to medical norms. They either used a standard mobile app, built a data representation from LEGO® bricks based on instructions, or completed a free-form brick build. We found that building with instructions fostered more comparison and using bricks fostered focused attention. The free-form condition required extra time to complete, and lacked usability. Our work shows that designing instructional physicalisation experiences for PI is a means of improving engagement and understanding of personal data.

While walking meetings offer a healthy alternative to sit-down meetings, they also pose practical challenges. Taking notes is difficult while walking, which limits the potential of walking meetings. To address this, we designed the Walking Talking Stick—a tangible device with integrated voice recording, transcription, and a physical highlighting button to facilitate note-taking during walking meetings. We investigated our system in a three-condition between-subjects user study with thirty pairs of participants (N=60) who conducted 15-minute outdoor walking meetings. Participants either used clip-on microphones, the prototype without the button, or the prototype with the highlighting button. We found that the tangible device increased task focus, and the physical highlighting button facilitated turn-taking and resulted in more useful notes. Our work demonstrates how interactive artifacts can incentivize users to hold meetings in motion and enhance conversation dynamics. We contribute insights for future systems which support conducting work tasks in mobile environments.

The prospect of machine consciousness cultivates controversy across media, academia, and industry. Assessing whether non-experts perceive technologies as conscious, and exploring the consequences of this perception, are yet unaddressed challenges in Human Computer Interaction (HCI). To address them, we surveyed 100 people, exploring their conceptualisations of consciousness and if and how they perceive consciousness in currently available interactive technologies. We show that many people already perceive a degree of consciousness in GPT-3, a voice chat bot, and a robot vacuum cleaner. Within participant responses we identified dynamic tensions between denial and speculation, thinking and feeling, interaction and experience, control and independence, and rigidity and spontaneity. These tensions can inform future research into perceptions of machine consciousness and the challenges it represents for HCI. With both empirical and theoretical contributions, this paper emphasises the importance of HCI in an era of machine consciousness, real, perceived or denied.

This paper analyses Human-Computer Interaction (HCI) literature reviews to provide a clear conceptual basis for authors, reviewers, and readers. HCI is multidisciplinary and various types of literature reviews exist, from systematic to critical reviews in the style of essays. Yet, there is insufficient consensus of what to expect of literature reviews in HCI. Thus, a shared understanding of literature reviews and clear terminology is needed to plan, evaluate, and use literature reviews, and to further improve review methodology. We analysed 189 literature reviews published at all SIGCHI conferences and ACM Transactions on Computer-Human Interaction (TOCHI) up until August 2022. We report on the main dimensions of variation: (i) contribution types and topics; and (ii) structure and methodologies applied. We identify gaps and trends to inform future meta work in HCI and provide a starting point on how to move towards a more comprehensive terminology system of literature reviews in HCI.

Technologies have become an integral part of physical activity. Yet, the majority of popular programs do not focus on promoting a genuine understanding of how sport affects our bodies. As apps and trackers persuade users to exercise more, lack of body awareness can be detrimental to health. In this work, we propose and evaluate the concept of in-session reflective feedback as a means to support informed exercise routines by design. We designed and implemented REPLAY, a system which presents users with a visualization of physiological signals (heart rate, movement) from body-worn sensors during high-intensity interval training (HIIT). Our evaluation showed that participants gained a better understanding of how their body reacted to physical activity, allowing them to understand its effect and recognize own weaknesses. Further, our work demonstrates how the type of feedback can significantly moderate a user's perceived exhaustion. We highlight how in-session reflective feedback using bodily signals can promote healthy and effective workouts through creating a deeper understanding of one's own body physiology and limits.

Exploring the great outdoors offers physical and mental health benefits. Hiking is healthy, provides a sense of accomplishment, and offers an opportunity to relax. However, a nature trip is not always possible, and there is a lack of evidence showing how these beneficial experiences can be replicated in Virtual Reality (VR). In response, we recruited (N=24) participants to explore a virtual mountain landscape in a within-subjects study with different levels of exertion: walking, using a chairlift, and teleporting. We found that physical exertion when walking produced significantly more positive emotions and mindfulness than other conditions. Our research shows that physically demanding outdoor activities in VR can be beneficial for the user and that the achievement of hiking up a virtual mountain on a treadmill positively impacts wellbeing. We demonstrate how physical exertion can be used to add mindfulness and positive affect to VR experiences and discuss consequences for VR designers.

Abstract Remote health monitoring (RHM) provides various benefits to older adults, but its use is still limited. Remote monitoring may help in avoiding emergencies and prolong users’ independence. To understand how to design systems which support older adults, we studied a large-scale remote health monitoring system. The system used fitness-grade smartwatches to monitor the vital signs of more than 2000 users constantly. To probe the lived experience of using RHM, we conducted an explorative interview study (N = 41) with operators, carers, and users of the RHM system. Our thematic analysis reveals that personalisation of care ecology is crucial for developing users’ confidence and trust in the system. We found that participation in RHM may catalyse positive changes in older adults’ lifestyles. Based on our findings, we formulate five recommendations for designing future health monitoring systems. Our work contributes to insights into the lived experience and stakeholder ecology of health monitoring systems.

Modern games make creative use of First- and Third-person perspectives (FPP and TPP) to allow the player to explore virtual worlds. Traditionally, FPP and TPP perspectives are seen as distinct concepts. Yet, Virtual Reality (VR) allows for flexibility in choosing perspectives. We introduce the notion of a perspective continuum in VR, which is technically related to the camera position and conceptually to how users perceive their environment in VR. A perspective continuum enables adapting and manipulating the sense of agency and involvement in the virtual world. This flexibility of perspectives broadens the design space of VR experiences through deliberately manipulating perception. In a study, we explore users’ attitudes, experiences and perceptions while controlling a virtual character from the two known perspectives. Statistical analysis of the empirical results shows the existence of a perspective continuum in VR. Our findings can be used to design experiences based on shifts of perception.

While systems that use Artificial Intelligence (AI) are increasingly becoming part of everyday technology use, we do not fully understand how AI changes design processes. A structured understanding of how designers work with AI is needed to improve the design process and educate future designers. To that end, we conducted interviews with designers who participated in projects which used AI. While past work focused on AI systems created by experienced designers, we focus on the perspectives of a diverse sample of interaction designers. Our results show that the design process of an interactive system is affected when AI is integrated and that design teams adapt their processes to accommodate AI. Based on our data, we contribute four approaches adopted by interaction designers working with AI: a priori, post-hoc, model-centric, and competence-centric. Our work contributes a pragmatic account of how design processes for AI systems are enacted.

Racket sports offer an enjoyable form of physical activity and are fertile ground for interactive technologies supporting new players. Yet, current research has neglected its potential to support not only active players but also coaches in their training methods. To investigate how interactive technologies can support skill acquisition in training, we designed an Electrical Muscle Stimulation (EMS) system that helps maintain the ready position in crossminton. We compared the system with a vibrotactile solution in a user study, interviewing novice players and experienced coaches about their perception of the system. The system allowed coaches to effectively and immediately guide players to the ready position. An EMS-based feedback system for coaches can potentially reduce delay (physical and cognitive) for trainees, as stated by coaches. Our work contributes insights into designing systems that facilitate learning sports techniques using interactive feedback.

Human perception lacks the capabilities to accurately assess distance. The recent Covid-19 pandemic outbreak rendered this ability particularly important. Augmenting our sense of distance can help maintain safe separation from others when required. To explore how systems can help users maintain physical distance, we designed, implemented and evaluated Gapeau—a head-mounted system for augmenting the sense of distance. Our system uses proximity sensors and thermal sensing to detect and measure the distance to other people. We conducted a validation protocol, an experiment, in which we compared different feedback modalities, and an in-the-wild study to evaluate Gapeau’s performance and suitability for use in social contexts. We found that our system enabled users to more accurately determine whether they were maintaining a safe distance from others. Vibration and auditory feedback were found most effective and usable. Gapeau was perceived as socially acceptable. Our work contributes insights for augmented sensing systems with social relevance.

Physical activity is entering the virtual realm. Zwift is an at-home cycling system that is enjoying increasing popularity, yet the specifics of the experience of a virtual cyclist have not been studied to date. Building virtual sports systems can make physical activity accessible to more diverse user groups. To understand how and why users engage in virtual cycling, we conducted n=22 interviews with Zwift users. Through charting the motivations behind using Zwift, we determined that it allowed users to engage in a range of cycling activities traditionally reserved for professional cyclists. Our work reports on key motivations and identifies five key strategies which Zwift uses to create an engaging virtual sports experience. Further, we discuss how Zwift creates a world of virtual professionalism. Our findings offer a structured understanding of the experience of Zwift which can be used to inspire the design of future virtual amateur sports systems.

Novel input methods for game design often excite users, especially if they extend the way one interacts with the system. Electromyography (EMG) has the inherent potential to provide an intuitive - yet challenging - input channel for interactive systems. While this difficulty in control often limits the scope of applications for EMG in most systems, we argue that these qualities are especially relevant for games and playful interaction. The inherently challenging qualities of EMG input make the modality a prime candidate for designing body-centric playful experiences. Yet, we still need to understand its limitations to create engaging rather than frustrating experiences for users. In this work, we investigate EMG's potential to support playful interaction through exploratory studies, deriving feasible game interactions based on EMG's technical constraints, and study their application in game design. Based on our findings, we highlight design implications and pitfalls to avoid when creating EMG-based entertainment systems.

Science faces a reproducibility crisis. There is a need to establish open science practices within the academic reputation economy. Open Science Badges address this issue by promoting and acknowledging research sharing and documentation. The generic design of currently awarded badges enabled their adoption across the sciences. Yet, their general nature makes it difficult to reflect individual practices and needs of distinct scientific fields. In this paper, we explore uses and effects of highly tailored badges in research data management. We implemented six science badges in a particle physics research preservation service. Our exploration showed that scientists were open to encouraging valuable scientific practices through tailored science badges. They described entirely new opportunities for interaction with research repositories. We present design implications for systems that promote reproducibility, related to meaningful criteria, repository navigation, and content discovery. Finally, we discuss the scope and uses of tailored science badges in modern science.

Current personal informatics models consider reflection as an important stage in users’ journeys with trackers. However, these models describe reflection from a meta perspective and it remains unclear what this stage entails. To design interactive technologies that support reflection, we need a more thorough understanding of how people reflect on their personal data in practice. To that end, we conducted semi-structured interviews with users of fitness trackers and an online survey to study practices in reflecting on fitness data. Our results show that users reported reflecting on data despite lacking reflection support from their tracking technology. Based on our results, we introduce the Technology-Mediated Reflection Model, which describes conditions and barriers for reflection on personal data. Our model consists of the temporal and conceptual cycles of reflection and helps designers identify the possible barriers a user might face when using a system for reflection.

Reflection is an often addressed design goal in Human-Computer Interaction (HCI) research. An increasing number of artefacts for reflection have been developed in recent years. However, evaluating if and how an interactive technology helps a user reflect is still complex. This makes it difficult to compare artefacts (or prototypes) for reflection, impeding future design efforts. To address this issue, we developed the Technology-Supported Reflection Inventory (TSRI), which is a scale that evaluates how effectively a system supports reflection. We first created a list of possible scale items based on past work in defining reflection. The items were then reviewed by experts. Next, we performed exploratory factor analysis to reduce the scale to its final length of nine items. Subsequently, we confirmed test-retest validity of our instrument, as well as its construct validity. The TSRI enables researchers and practitioners to compare prototypes designed to support reflection.

Avatars in virtual reality (VR) enable embodied experiences and induce the Proteus effect—a shift in behavior and attitude to mimic one’s digital representation. Previous work found that avatars associated with physical strength can decrease users’ perceived exertion when performing physical tasks. However, it is unknown if an avatar’s appearance can also influence the user’s physiological response to exercises. Therefore, we conducted an experiment with 24 participants to investigate the effect of avatars’ athleticism on heart rate and perceived exertion while cycling in VR following a standardized protocol. We found that the avatars’ athleticism has a significant and systematic effect on users’ heart rate and perceived exertion. We discuss potential moderators such as body ownership and users’ level of fitness. Our work contributes to the emerging area of VR exercise systems.

Interactive technologies are getting closer to our bodies and permeate the infrastructure of our homes. While such technologies offer many benefits, they can also cause an initial feeling of unease in users. It is important for Human-Computer Interaction to manage first impressions and avoid designing technologies that appear creepy. To that end, we developed the Perceived Creepiness of Technology Scale (PCTS), which measures how creepy a technology appears to a user in an initial encounter with a new artefact. The scale was developed based on past work on creepiness and a set of ten focus groups conducted with users from diverse backgrounds. We followed a structured process of analytically developing and validating the scale. The PCTS is designed to enable designers and researchers to quickly compare interactive technologies and ensure that they do not design technologies that produce initial feelings of creepiness in users.

Running is a widely popular physical activity that offers many health benefits. As runners progress with their training, understanding one’s own body becomes a key concern in achieving wellbeing through running. While extensive bodily sensing opportunities exist for runners, understanding complex sensor data is a challenge. In this paper, we investigate how data from shoe-worn sensors can be visualised to empower runners to improve their technique. We designed GraFeet—an augmented running shoe that visualises kinesiological data about the runner’s feet and gait. We compared our prototype with a standard sensor dashboard in a user study where users ran with the sensor and analysed the generated data after the run. GraFeet was perceived as more usable; producing more insights and less confusion in the users. Based on our inquiry, we contribute findings about using data from body-worn sensors to support physically active individuals.

Physical exercises can benefit our health, but avoiding improper form and overexertion is essential. Facilitating bodily insights can encourage learning about exercise form, allowing users to gain a deeper understanding of their physiology. To investigate this, we conducted a lab experiment where amateur users performed bicep curls, and interviews with sports coaches. Participants were provided with FitBack—a system that monitors muscle activity during exercises via electromyography (EMG) and offers real-time biofeedback. Amateurs reported that they were successful in improving their exercise form and could acquire deeper bodily insights. Coaches reflected on how understanding muscle activity through EMG could be effectively used for increasing body awareness during coaching, highlighting that EMG-based biofeedback is beneficial for a diverse set of users. Our work contributes insights into using bodily sensing to help users understand their bodies. We contribute guidelines for designing systems that use EMG biofeedback effectively in physical activity.

Fitness trackers have the potential for fostering sustained change and increasing well-being. However, the research community is yet to understand what design features and values need to be embodied in a fitness tracker for long-term engagement. While past work mainly focused on WEIRD (Western, Educated, Industrialised, Rich, Democratic) fitness trackers usersin North America and Western Europe, this paper investigates another perspective on fitness tracking. We conducted interviews with N = 37 fitness tracker users in the US, Europe and Egypt to identify the similarities and differences in attitudes and practices in fitness tracking. We found that fitness tracking involved a deeper social context in Egyptian communities and our findings suggest that Arabic users focused on physiological measurement, while non-Arab Western users appear to bewere more interested in goal achievement. We contribute design dimensions that can help build more inclusive tracker experiences. Our work highlights how future fitness trackers should support a customisable spectrum of design values to offer engaging experiences to a diverse and global audience.

Due to recent technological advancements, governments can exercise an unprecedented amount of power over their citizens. It is vital to understand how governments impose restrictions on citizens through digital technologies, especially if those restrictions can save lives. Here, we look at the case of Home Quarantine—a Polish government-mandated smartphone application whose use has become mandatory during the COVID-19 crisis. Users in quarantine are legally required to use the application, reporting location and take selfie photographs. We conducted an autoethnographic diary study of one author using the app during quarantine and interviews with 23 users. We found that the app assisted in creating quarantine life routines and affected social interactions. Users connected with the world outside quarantine through selfies. We also uncovered key reservations our users had about using this app. Our work broadens the understanding of location-based apps and practices around surveillance technologies.

While fitness trackers are increasingly popular among users, recent studies have shown that the health benefits of wearing a tracker are not apparent. The need to explicitly retrieve data can lead to limited benefits. Understanding how users can access, understand, and reflect on their data can lead to building systems that benefit our wellbeing. In this work, we explore the feasibility of using ubiquitous artifacts for unobtrusive feedback in health tracking. We evaluated a concept based on design dimensions for personal visualization on a smart mirror in a user study. Our design puts emphasis on the temporality of presented data. Participants found the visualizations comprehensive, rating cardiac and inertial data most useful as well as approved the different levels of temporal aggregation. Our work contributes findings on how to represent health-related data with ubiquitous artifacts to increase users’ awareness.

A steadily increasing number of notifications, auditory, visual or ambient, competes for the user’s attention. Frequent unsuitable notifications can lead to a breakdown in efficiency and increase error rates. This paper compares the effectiveness, disruptiveness, and user experience of three different notification modalities: On-Object, ambient On-Environment, and On-Smartphone notifications. In a user study with 24 participants, we evaluate the three notification modalities during a cooking task where users were frequently exposed to notifications. Our results show that ambient On-Environment notifications minimize the time in which users can resume their primary task. Ambient On-Environment notifications were also perceived as least disrupting compared to the other two notification modalities. We discuss the design requirements for non-disruptive notifications in smart home environments and conclude with future strategies for notifying users at different urgency levels.

Mountain Biking (MTB) is an increasingly popular outdoors activity which offers a unqiue connection to nature along with the health benefits of cardiovascular exercise. Yet, complex MTB technique is an entry barrier that often prevent novices from enjoying the sport. Developing interactive systems, which can support developing MTB proficiency can augment the outdoor experience and make the sport available to a larger group of users. To that end, we designed, implemented and evaluate MTBalance - a system which provides body posture feedback for beginner mountain bikers. Based on inertial tracking, MTBalance informs the user about how to correct their posture to improve MTB performance. We conducted a study in which we compared different feedback modalities for MTBalance. We observed that the system increased perceived balance awareness. Our work provides insights for designing body awareness systems for outdoor sports.

Traditional meetings involve extensive sitting, which negatively impacts the health of attendees. Understanding how technology can facilitate integrating physical activity into the workplace, such as in walking meetings, is vital to improving workplace wellbeing. To that end, we applied a mixed-method approach to explore requirements and opportunities for walking meetings. We conducted an online questionnaire and a series of interviews with early adopters of walking meetings and created design fictions based on their feedback. We evaluated the design fictions with a second questionnaire and garnered additional feedback from the original early adopters. Based on our findings, we derived four dimensions associated with walking meetings: practical, environmental, social, and cognitive facets. We define attributes, challenges, and opportunities within these dimensions which are important for designing systems that support walking meetings. Our work identifies key considerations for developing systems that integrate physical activity into communication activities.

Body movements, from a short smile to a marathon run, are driven by muscle activity. Despite the fact that measuring muscle activity with electromyography (EMG) is technically well established, it is highly complex and its use in interfaces has been limited. Easy access to muscle sensing can offer new opportunities to Human-Computer Interaction (HCI) research. Off-the-shelf sensors often only provide low-level access, hence requiring expertise in signal processing and widening the gulf of execution for users without engineering skills. To address this challenge, we introduce EMBody, a data-centric toolkit for EMG-based interface prototyping and experimentation. EMBody offers multiple levels of prototyping fidelity for EMG sensing, signal processing, and data interpretation. Our data-centric toolkit encapsulates the different data representation stages, offering a wide range of customization opportunities to experts while also allowing non-technical designers to focus on creating new interaction techniques. EMBody features a lightweight form factor and wireless connectivity. Additionally, the system leverages an exploration-centered workflow by allowing rapid access to measurement data via the accompanying software. Users define a set of motions to be recognized and interactively provide example data points. The toolkit then handles signal processing and classification. The recognized movements are streamed on the local network, ready to be used by interactive applications. This paper reports on how to use EMBody and its implementation. We iteratively developed the toolkit in a series of workshops and example applications. Users who had none or very limited knowledge of EMG could rapidly create engaging functional prototypes, while experts appreciated the modularity of the software component allowing for a high degree of customization. We contribute the software and hardware components of EMBody as a tool for the research community to stimulate creative exploration of EMG systems.

Improvising on the piano keyboard requires extensive skill development, which may reduce the feeling of immersion and flow for amateur players. However, being able to add simple musical effects greatly boosts a player's ability to express their unique playing style. To simplify this process, we designed an electromyography-based (EMG) system which integrates seamlessly into normal play by allowing musicians to modulate sound pitch using their thumb. We conducted an exploratory user study where users played a predefined melody and improvised using our system and a standard pitch wheel. Interview responses and survey answers showed that the EMG-based system supported the players' musical flow. Additionally, interviews indicated the system's capabilities to foster player creativity, and that players enjoyed experimenting with the effect. Our work illustrates how EMG can support seamless integration into existing systems to extend the range of interactions provided by a given interface.

Fitness trackers encourage users to set goals to improve personal wellbeing, but these goals sometimes remain unmet. Understanding how improved ways of communicating failure to meet fitness goals could help prevent negative thought cycles (rumination) and avoid reduced motivation for physical activity. To address this challenge, we studied how unmet goals can be presented in apps. We designed prototypes that showed unmet fitness goals. Radial and regular bar charts, single-coloured and multicoloured were used in the study. In a survey (n = 165), we compared the four versions and a textual description of the unmet goals. Then, we conducted follow-up interviews (n = 20) to gain a detailed understanding of the perceptions and feelings evoked by the prototypes. We found that bar graphs offered a significantly better potential for reflection and multicoloured charts triggered significantly more rumination. We contribute in-depth insights into designing systems that use goals and avoid potential negative effects of personal tracking.

The more people commute by bicycle, the higher is the number of cyclists using their smartphones while cycling and compromising traffic safety. We have designed, implemented and evaluated two prototypes for smartphone control devices that do not require the cyclists to remove their hands from the handlebars—the three-button device Tribike and the rotation-controlled Brotate. The devices were the result of a user-centred design process where we identified the key features needed for a on-bike smartphone control device. We evaluated the devices in a biking exercise with 19 participants, where users completed a series of common smartphone tasks. The study showed that Brotate allowed for significantly more lateral control of the bicycle and both devices reduced the cognitive load required to use the smartphone. Our work contributes insights into designing interfaces for cycling.

Augmented Reality (AR) and wearable sensors offer new possibilities to expand our senses and change how we interact with the world. Sensory augmentation can be integrated into everyday activities, but controls remain a challenge for user experience. In this paper, we investigate how users can control a futuristic interface that enables in-situ magnification. We designed an interactive system to enable users to zoom in on objects up to a microscopic level and implemented a prototype using the Microsoft Hololens. In a user-study, we compared full-screen to windowed visualizations and four interaction techniques for zooming: a clicker, two types of gestures, and voice. Our results indicate that the clicker enabled users to zoom at the fastest rate and lowered cognitive load. We also found a preference for windowed views. With our work, we provide insights for future augmented vision systems.

Smart speakers become increasingly ubiquitous in our homes. Consequently, we need to study how smart speakers affect the members of a household. Understanding the adoption of a smart speaker can assure it does not negatively influence the social dynamics within a household and create opportunities for further assistance. We deployed an Amazon Echo dot in nine households with 20 inhabitants who were new smart speaker users. We conducted multiple interviews, inquiring how a smart speaker was integrated into a household from day one. We investigated the development of social rules around using the device and how the smart speaker was appropriated. Users developed different strategies of using the device which altered social behaviours in some households. Further, we identified barriers and unmet requirements in introducing smart speakers to home environments. Our work contributes to an understanding of ubiquitous assistance for user groups at home.

With the rise of the Internet of Things, home appliances become connected and they can proactively provide status information to users. Facing a steadily increasing number of notification sources, it is unclear how information from smart home devices should be provided without overloading the users’ attention. In this paper, we investigate the design of non-urgent smart home notifications using a smart plant system. Based on feedback from focus groups, we designed four notification types and compared them in an eight-week in-situ study. We show that notifications displayed on smart home devices are preferred to those received on smartphones. Event-based notifications are unobtrusive, actionable and are preferred to persistent notifications. We derive guidelines that address the need of being in control, opportune locations for notification delivery at opportune moments, notification blindness, the importance of discretizing continuous information, and combining related notifications.

Collocated interaction has received growing interest in both academic research and the design of information and communication technological applications. An emergent research topic within this area relates to technological enhancement of social interaction. Various envisioned systems aim beyond simply enabling interaction, to actively enhance—i.e., improve the quality or extent of—social interaction between collocated people. However, there is little understanding of the optimal design solutions and roles of technology considering this goal. This literature review outlines the landscape of design explorations in this emergent research topic. We contribute an in-depth study of 92 publications that present relevant solutions or prototypes, analyzing their focus areas, design objectives, and design and evaluation approaches. To contribute with a new theoretical perspective, we identify various roles of technology relevant for enhancement, representing three abstract categories: facilitating, inviting and encouraging. This review helps researchers to describe, analyze, and position relevant prior research and identify gaps in scientific knowledge.

As science becomes increasingly data-intensive, the requirements for comprehensive Research Data Management (RDM) grow. This often overwhelms scientists, requiring more workload and training. The failure to conduct effective RDM leads to producing research artefacts that cannot be reproduced or reused. Past research placed high value on supporting data science workers, but focused mainly on data production, collection, processing, and sensemaking. In order to understand practices and needs of data science workers in relation to documentation, preservation, sharing, and reuse, we conducted a cross-domain study with 15 scientists and data managers from diverse scientific domains. We identified five core concepts which describe requirements, drivers, and boundaries in the development of commitment for RDM, essential for generating reproducible research artefacts: Practice, Adoption, Barriers, Education, and Impact. Based on those concepts, we introduce a stage-based model of personal RDM commitment evolution. The model can be used to drive the design of future systems that support a transition to open science. We discuss infrastructure, policies, and motivations involved at the stages and transitions in the model. Our work supports designers in understanding the constraints and challenges involved in designing for reproducibility in an age of data-driven science.

While the sport of golf offers unique opportunities for people of all ages to be active, it also requires mastering complex movements before it can be fully enjoyed. Extensive training is required to begin achieving any success, which may demotivate prospective players away from the sport. To aid beginner golfers and enable them to practice without supervision, we designed Subtletee---a system that enhances the bodily awareness of golfers by providing feedback on the position of their feet and elbows. We first identified key problems golf beginners face through expert interviews. We then evaluated different feedback modalities for Subtletee---visual, tactile and auditory in an experiment with 20 beginner golfers. We found that providing proprioception feedback increased the users' performance on the driving range, with tactile feedback providing the most benefits. Our work provides insights on delivering feedback during physical activity that requires high precision movements.

Reproducibility should be a cornerstone of scientific research and is a growing concern among the scientific community and the public. Understanding how to design services and tools that support documentation, preservation and sharing is required to maximize the positive impact of scientific research. We conducted a study of user attitudes towards systems that support data preservation in High Energy Physics, one of science's most data-intensive branches. We report on our interview study with 12 experimental physicists, studying requirements and opportunities in designing for research preservation and reproducibility. Our findings suggest that we need to design for motivation and benefits in order to stimulate contributions and to address the observed scalability challenge. Therefore, researchers' attitudes towards communication, uncertainty, collaboration and automation need to be reflected in design. Based on our findings, we present a systematic view of user needs and constraints that define the design space of systems supporting reproducible practices.

The need for data preservation and reproducible research is widely recognized in the scientific community. Yet, researchers often struggle to find the motivation to contribute to data repositories and to use tools that foster reproducibility. In this paper, we explore possible uses of gamification to support reproducible practices in High Energy Physics. To understand how gamification can be effective in research tools, we participated in a workshop and performed interviews with data analysts. We then designed two interactive prototypes of a research preservation service that use contrasting gamification strategies. The evaluation of the prototypes showed that gamification needs to address core scientific challenges, in particular the fair reflection of quality and individual contribution. Through thematic analysis, we identified four themes which describe perceptions and requirements of gamification in research: Contribution, Metrics, Applications and Scientific practice. Based on these, we discuss design implications for gamification in science.

While Virtual Reality continues to increase in fidelity, it remains an open question how to effectively reflect the user's movements and provide congruent feedback in virtual environments. We present VRsneaky, a system for producing auditory movement feedback, which helps participants orient themselves in a virtual environment by providing footstep sounds. The system reacts to the user's specific gait features and adjusts the audio accordingly. In a user study with 28 participants, we found that VRsneaky increases users' sense of presence as well as awareness of their own posture and gait. Additionally, we find that increasing auditory realism significantly influences certain characteristics of participants' gait. Our work shows that gait-aware audio feedback is a means to increase presence in virtual environments. We discuss opportunities and design requirements for future scenarios where users walk through immersive virtual worlds.

While we usually have no trouble with orientation, our sense of direction frequently fails in the absence of a frame of reference. Open-water swimmers raise their heads to look for a reference point, since disorientation might result in exhaustion or even drowning. In this paper, we report on Clairbuoyance - a system that provides feedback about the swimmer's orientation through lights mounted on swimming goggles. We conducted an experiment with two versions of Clairbuoyance: Discrete signals relative to a chosen direction, and continuous signals providing a sense of absolute direction. Participants swam to a series of targets. Proficient swimmers preferred the discrete mode; novice users the continuous one. We determined that both versions of Clairbuoyance enabled reaching the target faster than without the help of the system, although the discrete mode increased error. Based on the results, we contribute insights for designing directional guidance feedback for swimmers.

While Augmented Reality (AR) technologies are becoming increasingly available, our understanding of AR is primarily limited to controlled experiments which address use at work or for entertainment. Little is known about how it could enhance everyday interaction from a user's perspective. Personal use of AR at home may improve how users' interface with information on a daily basis. Through an online survey, we investigated attitudes towards domestic AR. We further explored the opportunities for AR at home in a technology probe. We first introduced the users to AR by offering an AR experience presented through mixed reality smart glasses. We then used a tailor-made tablet application to elicit photos illustrating how users imagine future AR experiences. Finally, we conducted semi-structured interviews based on elicited photos. Our results show that users are eager to benefit from on-demand information, assistance, enhanced sensory perception, and play offered by AR across many locations at home. We contribute insights for future AR systems designed for domestic environments.

Recent work demonstrated the opportunities of thermal imaging in the development of novel interactive systems. However, the exploration is limited to controlled lab setups. Hence, little we know about how thermal imaging could be useful for a broader range of daily applications by novice users. To investigate the potential of domestication of thermal imaging, we conducted an exploration with a technology-cultural probe. Ten households (26 individuals) used a mobile thermal camera in their daily life. We collected thermal photos taken by the participants and conducted interviews after using the camera. We found that the users were excited about using thermal cameras in their everyday lives and found many practical uses for them. Our study provides insights into how novice users wish to use thermal imaging technology to augment their vision in daily setups, as well as identifying and classifying common thermal imaging use cases. Our work contributes implications for designing thermal imaging devices targeted towards novice users.

While facilitated brainstorming is a proven ideation method for professional teams, distributed teams are currently not able to enjoy its benefits. As workers are shifting towards collaborating in distributed settings, understanding how interactive systems can support facilitated brainstorming is becoming necessary to ensure that distributed teams remain creative. To address this challenge we designed, implemented, and evaluated DigiMetaplan---an interactive surface-based system for distributed facilitated brainstorming for co-located and remote users. The design of DigiMetaplan was inspired by a widely-used facilitated brainstorming method called Metaplan, where the brainstorming process of a group is coordinated by a facilitator. We evaluated the usability of DigiMetaplan with five hybrid teams consisting of a co-located facilitator and two team members connected with one remote participant. Results showed that the features used in DigiMetaplan on interactive surfaces effectively supported teams in performing facilitated collaborative brainstorming in partially distributed settings. We contribute knowledge on how a brainstorming environment translated into a multi-surface distributed system affects facilitated collaboration.

Navigating on large high-resolution displays (LHRDs) using devices built for traditional desktop computers can be strenuous and negatively impact user experience. As LHRDs transition to everyday use, new user-friendly interaction techniques need to be designed to capitalise on the potential offered by the abundant screen space on LHRDs. We conducted a study which compared mouse pointing and eye-tracker assisted pointing (MAGIC pointing) on LHRDs. In a controlled experiment with 35 participants, we investigated user performance in a one-dimensional pointing task and a map-based search task. We determined that MAGIC pointing had a lower throughput, but participants had the perception of higher performance. Our work contributes insights for the design of pointing techniques for LHRDs. The results indicate that the choice of technique is scenario-dependent which contrasts with desktop computers.

As architects usually decide on the shape and look of windows during the design of buildings, opportunities for interactive windows have not been systematically explored yet. In this work, we extend the vision of sustainable and comfortable adaptive buildings using interactive smart windows. We systematically explore the design space of interactive windows to chart requirements, constraints, and challenges. To that end, we built proof-of-concept prototypes of smart windows with fine-grained control of transparency. In two studies, we explored user attitudes towards interactive windows and elicited control methods. We found that users understand and see potential for interactive windows at home. We provide specific usage contexts and specify interactions that may facilitate domestic applications. Our work illustrates the concept of interactive smart windows and provides insights regarding their design, development, and user controls for adaptive walls. We identify design dimensions and challenges to stimulate further development in the domain of adaptive buildings.

Mastering fine motor tasks, such as playing the guitar, takes years of time-consuming practice. Commonly, expensive guidance by experts is essential for adjusting the training program to the student's proficiency. In our work, we showcase the suitability of Electromyography to detect fine-grained hand and finger postures in an exemplary guitar tutor scenario. We present EMGuitar, an interactive guitar tutoring system, that assists students by reporting on play correctness and adjusts playback tempi automatically. We report person-dependent classification utilizing a ring of electrodes around the forearm with an F1 score of up to 0.89 on recorded calibration data. Furthermore, our system was received well by neither diminishing ease of use nor being disruptive for the participants. Based on the received comments, we identified the need for detailed play accuracy feedback down to individual chords, for which we suggest an adapted visualization and an algorithmic approach.

A common objective for context-aware computing systems is to predict how user interfaces impact user performance regarding their cognitive capabilities. Existing approaches such as questionnaires or pupil dilation measurements either only allow for subjective assessments or are susceptible to environmental influences and user physiology. We address these challenges by exploiting the fact that cognitive workload influences smooth pursuit eye movements. We compared three trajectories and two speeds under different levels of cognitive workload within a user study (N=20). We found higher deviations of gaze points during smooth pursuit eye movements for specific trajectory types at higher cognitive workload levels. Using an SVM classifier, we predict cognitive workload through smooth pursuit with an accuracy of 99.5% for distinguishing between low and high workload as well as an accuracy of 88.1% for estimating workload between three levels of difficulty. We discuss implications and present use cases of how cognition-aware systems benefit from inferring cognitive workload in real-time by smooth pursuit eye movements.

Individuals with cognitive impairments currently leverage extensive human resources during their transitions from assisted living to independent living. In Western Europe, many government-supported volunteer organizations provide sheltered living facilities; supervised environments in which people with cognitive impairments collaboratively learn daily living skills. In this paper, we describe communal cooking practices in sheltered living facilities and identify opportunities for supporting these with interactive technology to reduce volunteer workload. We conducted two contextual observations of twelve people with cognitive impairments cooking in sheltered living facilities and supplemented this data through interviews with four employees and volunteers who supervise them. Through thematic analysis, we identified four themes to inform design requirements for communal cooking activities: Work organization, community, supervision, and practicalities. Based on these, we present five design implications for assistive systems in kitchens for people with cognitive deficiencies.

Previous work has shown that large high resolution displays (LHRDs) can enhance collaboration between users. As LHRDs allow free movement in front of the screen, an understanding of movement behavior is required to build successful interfaces for these devices. This paper presents Pac-Many; a multiplayer version of the classical computer game Pac-Man to study group dynamics when using LHRDs. We utilized smartphones as game controllers to enable free movement while playing the game. In a lab study, using a 4m × 1m LHRD, 24 participants (12 pairs) played Pac-Many in collaborative and competitive conditions. The results show that players in the collaborative condition divided screen space evenly. In contrast, competing players stood closer together to avoid benefits for the other player. We discuss how the nature of the task is important when designing and analyzing collaborative interfaces for LHRDs. Our work shows how to account for the spatial aspects of interaction with LHRDs to build immersive experiences.

While the proliferation of mobile devices has rendered mobile notifications ubiquitous, researchers are only slowly beginning to understand how these technologies affect everyday social interactions. In particular, the negative social influence of mobile interruptions remains unexplored from a methodological perspective. This paper contributes a mixed-method evaluation procedure for assessing the disruptive impact of mobile interruptions in conversation. The approach combines quantitative eye tracking, qualitative analysis, and a simulated conversation environment to enable fast assessment of disruptiveness. It is intended to be used as a part of an iterative interaction design process. We describe our approach in detail, present an example of its use to study a new call declining technique, and reflect upon the pros and cons of our approach.

While the number of users sporting fitness trackers is constantly increasing, little is understood about how tracking goals can evolve over time. As recent studies have shown that the long-term health effects of trackers are limited, we need to readdress how trackers engage users. We conducted semi-structured interviews and an online survey to explore how users change their tracking goals. Based on our results, we created the Tracker Goal Evolution Model. The model describes how tracker goals can evolve from internal user needs through qualitative goals to quantitative goals that can be used with trackers. It also includes trust and reflection as key contextual factors contributing to meaningful transitions between goals. We postulate showing how tracker goals relate to other personal fitness goals as key for long-term engagement with trackers. Our model is useful for designers of future trackers as a tool to create evolving and meaningful tracking goals.

Smart glasses are increasingly being used in professional contexts. Having key applications such as short messaging and newsreader, they enable continuous access to textual information. In particular, smart glasses allow reading while performing other activities as they do not occlude the user's world view. For efficient reading, it is necessary to understand how a text should be presented on them. We, therefore, conducted a study with 24 participants using a Microsoft HoloLens to investigate how to display text on smart glasses while walking and sitting. We compared text presentation in the top-right, center, and bottom-center positions with Rapid Serial Visual Presentation (RSVP) and line-by-line scrolling. We found that text displayed in the top-right of smart glasses increases subjective workload and reduces comprehension. RSVP yields higher comprehension while sitting. Conversely, reading with scrolling yields higher comprehension while walking. Insights from our study inform the design of reading interfaces for smart glasses.

Human vision is limited to a small band of the electromagnetic spectrum. It has been shown that extending visual perception can be beneficial, but it is unclear if this is useful for a broader range of applications. In this paper, we explore user reactions to extended visual perception. We describe the design and implementation of TriSight, a head-mounted display that allows the user to perceive the environment in the visual spectrum, the thermal spectrum, and through depth maps. In a study, we asked participants to perform everyday tasks in a created home, kitchen, office and basement with TriSight. Through analyzing videos, interviews, questionnaires and logs we chart the users' feedback towards the augmented visual perception. Our findings, imply the positive impact of extended vision, as well as the potential of thermal vision as alternative perception mode in performing daily tasks. Finally, we discuss the implications for designing devices that extend human's visual perception beyond the visual spectrum.

While outdoor sport activities keep gaining popularity as part of a global trend to maintain a healthier lifestyle, current technology offers limited support for activity-specific needs. Therefore, a greater understanding of information sharing behaviours is necessary in order to build comprehensive, socially-embedded sports applications. To this purpose, we interviewed 46 practitioners in three outdoor sports: trail running, climbing, and skiing. Our qualitative study investigates how participants share information in the context of outdoor sports and how current technology supports this practice. Through thematic analysis, we derived five themes that describe the current information sharing practices: nature, risk and planning, content selection, audience selection, and privacy. Based on these themes, we present five recommendations for design that can inform, inspire and refine future sharing technologies for outdoor sport.

Textual communication via mobile phones suffers from a lack of context and emotional awareness. We present a mobile chat application, HeartChat, which integrates heart rate as a cue to increase awareness and empathy. Through a literature review and a focus group, we identified design dimensions important for heart rate augmented chats. We created three concepts showing heart rate per message, in real-time, or sending it explicitly. We tested our system in a two week in-the-wild study with 14 participants (7 pairs). Interviews and questionnaires showed that HeartChat supports empathy between people, in particular close friends and partners. Sharing heart rate helped them to implicitly understand each other's context (e.g. location, physical activity) and emotional state, and sparked curiosity on special occasions. We discuss opportunities, challenges, and design implications for enriching mobile chats with physiological sensing.

We are often confronted with information interfaces designed in an unfamiliar language, especially in an increasingly globalized world, where the language barrier inhibits interaction with the system. In our work, we explore the design space for building interfaces that can detect the user's language proficiency. Specifically, we look at how a user's gaze properties can be used to detect whether the interface is presented in a language they understand. We report a study (N=21) where participants were presented with questions in multiple languages, whilst being recorded for gaze behavior. We identified fixation and blink durations to be effective indicators of the participants' language proficiencies. Based on these findings, we propose a classification scheme and technical guidelines for enabling language proficiency awareness on information displays using gaze data.

While most current interactive surfaces use only the position of the finger on the surface as the input source, previous work suggests using the finger orientation for enriching the input space. Thus, an understanding of the physiological restrictions of the hand is required to build effective interactive techniques that use finger orientation. We conducted a study to derive the ergonomic constraints for using finger orientation as an effective input source. In a controlled experiment, we systematically manipulated finger pitch and yaw while performing a touch action. Participants were asked to rate the feasibility of the touch action. We found that finger pitch and yaw do significantly affect perceived feasibility and 21.1% of the touch actions were perceived as impossible to perform. Our results show that the finger yaw input space can be divided into the comfort and non-comfort zones. We further present design considerations for future interfaces using finger orientation.

Interactive systems, such as online search interfaces, require appropriate input if they are to produce accurate information. Without this, they can be inaccurate if the user is uncertain about the keywords. Current systems do not have the means to detect uncertainty, which may lead to a negative user experience. We explore physiological and behavioral measurements as tools to implicitly detect users' uncertainty, and provide a method to integrate input variability in interactive systems. We conducted a laboratory study where participants answered questions of varying difficulty, recording physiological data via a key logger, an eye tracker, and a heart rate sensor. Our results show that participants spent significantly more time on difficult questions and looked longer at their answers before submitting them. Based on our results, we provide initial insights on how data from physiological sensors and logged user behavior can be utilized to enrich interactive systems and evaluate a user's uncertainty level.

Large high-resolution displays (LHRDs) present new opportunities for interaction design in areas such as interactive visualization and data analytics. Design processes for graphical interfaces for LHRDs are still challenging. In this paper, we explore the design space of graphical interfaces for LHRDs by engaging in the creation of four prototypes for supporting office work. Specifically, we investigate how users can effectively manage application windows on LHRDs using four window alignment techniques: curved zooming, window grouping, window spinning and side pane navigation. We present the design and implementation of these window alignment techniques in a sample office application. Based on a mixed-methods user study of our prototypes, we contribute insights on designing future graphical interfaces for LHRDs. We show that potential users appreciate techniques, which enhance focus switching without changing the spatial relation between related windows.

Despite the proliferation of screens in everyday environments, providing values to remote displays for exploring complex data sets is still challenging. Enhanced input for remote screens can increase their utility and enable the construction of rich data-driven environments. Here, we investigate the opportunities provided by a variable movement resistance slider (VMRS), based on a motorized slide potentiometer. These devices are often used in professional soundboards as an effective way to provide discrete input. We designed, built and evaluated a remote input device using a VMRS that facilitates choosing a number on a discrete scale. By comparing our prototype to a traditional slide potentiometer and a software slider, we determined that for conditions where users are not looking at the slider, VMRS can offer significantly better performance and accuracy. Our findings contribute to the understanding of discrete input and enable building new interaction scenarios for large display environments.

Most existing colorblind aids help their users to distinguish and recognize colors but not compare them. We present HaptiColor, an assistive wristband that encodes discrete color information into spatiotemporal vibrations to support colorblind users to recognize and compare colors. We ran three experiments: the first found the optimal number and placement of motors around the wrist-worn prototype, and the second tested the optimal way to represent discrete points between the vibration motors. Results suggested that using three vibration motors and pulses of varying duration to encode proximity information in spatiotemporal patterns is the optimal solution. Finally, we evaluated the HaptiColor prototype and encodings with six colorblind participants. Our results show that the participants were able to easily understand the encodings and perform color comparison tasks accurately (94.4% to 100%).

Synchronous colocated collaborative sensemaking requires that analysts share their information and insights with each other. The challenge is to know when is the right time to share what information without disrupting the present state of analysis. This is crucial in ad-hoc sensemaking sessions with mobile devices because small screen space limits information display. To address these tensions, we propose and evaluate RAMPARTS - a spatially aware sensemaking system for collaborative crime analysis that aims to support faster information sharing, clue-finding, and analysis. We compare RAMPARTS to an interactive tabletop and a paper-based method in a controlled laboratory study. We found that RAMPARTS significantly decreased task completion time compared to paper, without affecting cognitive load or task completion time adversely compared to an interactive tabletop. We conclude that designing for ad-hoc colocated sensemaking on mobile devices could benefit from spatial awareness. In particular, spatial awareness could be used to identify relevant information, support diverse alignment styles for visual comparison, and enable alternative rhythms of sensemaking.

Proper break taking during office work iss necessary to prevent musculoskeletal disorders and reduce the risk of heart disease.We present APOEW -an avatar for preventing continuous office work without taking breaks.APOEW is a system that uses a personalized robot avatar to encourage proper break behaviour during office work.The avatar signals the need for a break by stooping.The system was designed to be unobtrusive and blend well with the office environment.The avatars are customisable in order to enable users to design their work environment freely.We conducted a user study where we observed developers working in front of their computers next to the avatar.Preliminary results indicate it has no negative impact on the work environment and users are intrigued by the system.Moreover, a survey on attitude to our concept reveals interesting and positive feedback that will help to develop an APOEW system further.

Motion tracking systems are gaining popularity and have a number of applications in research, entertainment, and arts. These systems must be calibrated before use. This process requires extensive user effort to determine a 3D coordinate system with acceptable accuracy. Usually, this is achieved by rapidly manipulating a calibration device (e.g. a calibration wand) in a volume for a set amount of time. While this is a complex spatial input task, improving the user experience of calibration inspired little research. This paper presents the design, implementation, and evaluation of WAVI --- a prototype device mounted on a calibration wand to jointly provide visual and tactile feedback during the calibration process. We conducted a user study that showed that the device significantly increases calibration quality without increasing user effort. Based on our experiences with WAVI, we present new insights for improving motion tracking calibration and complex spatial input.

This work aims at bringing empirical knowledge on Human-Robot Interaction obtained from user studies closer to being integrated into the capabilities of robots currently available on the market. The Takagi-Sugeno-Kang method and results of a user study conducted with thirty two participants were used to build a fuzzy data-based model for Human-Robot Proxemics. The experiment investigated the effect of robot approach distance and angle on perceived human comfort. The proposed model, consisting of a set of rules, fuzzy sets and their parameters, can be used by the robotics community thanks to their formal form. It can also be directly translated into natural language statements. Results of model cross-validation are reported.

In this article, we present a novel application domain for human computation, specifically for crowdsourcing, which can help in understanding particle-tracking problems. Through an interdisciplinary inquiry, we built a crowdsourcing system designed to detect tracer particles in industrial tomographic images, and applied it to the problem of bulk solid flow in silos. As images from silo-sensing systems cannot be adequately analyzed using the currently available computational methods, human intelligence is required. However, limited availability of experts, as well as their high cost, motivates employing additional nonexperts. We report on the results of a study that assesses the task completion time and accuracy of employing nonexpert workers to process large datasets of images in order to generate data for bulk flow research. We prove the feasibility of this approach by comparing results from a user study with data generated from a computational algorithm. The study shows that the crowd is more scalable and more economical than an automatic solution. The system can help analyze and understand the physics of flow phenomena to better inform the future design of silos, and is generalized enough to be applicable to other domains.

Motivation studies on running are often focused on how to convince non-runners to run, mainly through designing for extrinsic motivations such as health concerns or external reward systems. In contrast, we conducted a structured inquiry into understanding how to design technology for those whom are already committed to running and participate in organized races. Through interviews, focus groups, ethnographic observation, questionnaires, and design-based research over the course of two years, we investigated the needs of the advanced amateur runner community. An analysis of the gathered data led to five design themes -- Festival, Competition, Practicalities, Togetherness, and Support -- to inform future runner motivation technology. While flow theory appears to be a convenient tool to understand support during a race, we observed a number of other factors that need to be considered. Through combining the themes with previous research, we conclude by presenting nine guidelines for designing technology for this domain.

This paper explores remote cheering during amateur races through a formative design inquiry. Friends and family of advanced amateur runners are part of their running experience. Runners rely on support during the race day and it is usually provided in the form of co-located cheers. RUFUS -- a prototype remote ambient runner support system -- was developed. The system enables supporters to send three types of signals to runners during a race and runners can send signals back to supporters. Input from supporters is sent through a webpage and received by runners through a device designed to lower distraction. An in situ study was conducted to evaluate the prototype during an organized race. Results show that two-way communication between runners and supporters was achieved. We also found that our system reflected varying user needs correctly. Runners and supporters reported increased motivation and enhanced race experience through feeling connected.

This paper describes the design of a system providing room occupancy information in a university campus. The system and its possible influence on the human environment are designed to enhance the work environment through pervasive information delivery. The work is motivated by recent advances in the domain of ubiquitous computing. The authors describe a case study of delivering a solution to university students informing them where they can find free spaces in rooms designated for quiet study. The data is available on the web and through ambient displays. The proof-of-concept study presents the methodology applied, discusses the design issues that were encountered by the project team and reflects on the devices and techniques used in the implementation. An application of standard image processing techniques to provide a contextualized, pervasive user-centered service is also depicted.

This papers shows attempt of using prior knowledge in order to learn about the industrial process system behaviour. The system being studied here is the pneumatic conveying of solids monitored with electrical capacitance tomography (ECT). The prior knowledge is the non-invasive measurement information derived on the basis of intentionally introduced structural change in the experimental process flow rig. The focus is on the examination of pseudo-emergency states of bulk flow. Real case pneumatic transport failure usually consists in pipeline blockage. Such blockage typically develops starting as material slug build up. In contrast, our experiments investigate artificially induced flow pre-blockage states monitored with ECT measurement system. Collected measurement data are contextually processed in order to detect the pipeline state in sense of flow regime and flow behaviour. ECT raw data analysis strives to uncover a relation between measured values and flow change tendency. This research is aimed at giving rise to conclusions about possibility of contextual data processing in order to properly adjust pneumatic conveying control and a possible role of ECT records in this aspect. Authors show here that for now it is possible to detect abnormal process state such as blockage signal and the presented methodology coupled with nowadays computational techniques are anticipated to lead to abnormal states forecasting such as blockage threat recognition.