MoodShaper: A Virtual Reality Experience to Support Managing Negative EmotionsNegative 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 either 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.2024NWNadine Wagener et al.Immersion & Presence ResearchVR Medical Training & RehabilitationMental Health Apps & Online Support CommunitiesDIS
ProtoBricks: A Research Toolkit for Tangible Prototyping & Data PhysicalizationBuilding 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.2024JDJulia Dominiak et al.Data PhysicalizationCircuit Making & Hardware PrototypingDIS
Requirements and Attitudes towards Explainable AI in Law EnforcementIn high-stakes areas such as law enforcement, where artificial intelligence has the potential to enhance effectiveness and inclusivity, its decisions must be both informed and accountable. Thus, designing explainable artificial intelligence (XAI) for such settings is a key social concern. Yet, explanations in practice are often overly technical or abstract. To address this, our study engaged with police employees in an EU country, who are users of a text classifier. We found that for them, usability and usefulness are paramount in explanation design, whereas interpretability and understandability are less emphasized. Drawing from these insights, we suggest design guidelines centred on clarity and relevance for domain experts. We contribute recommendations which guide XAI system designers to better cater to the specific needs of specialized users and promote the responsible use of AI tools in public service.2024EHElize Herrewijnen et al.Explainable AI (XAI)AI Ethics, Fairness & AccountabilityDIS
Screenless Interactive Tabletop Gaming with Capacitive Surface SensingMany 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.2024KAKrzysztof Adamkiewicz et al.Lodz University of TechnologySerious & Functional GamesDigitalization of Board & Tabletop GamesCHI
Assessing User Apprehensions About Mixed Reality Artifacts and Applications: The Mixed Reality Concerns (MRC) QuestionnaireCurrent 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.2024CKChristopher Katins et al.HU BerlinMixed Reality WorkspacesPrivacy by Design & User ControlSmart Home Privacy & SecurityCHI
Designing Reflective Derived Metrics for Fitness TrackersPersonal tracking devices are equipped with more and more sensors and offer an ever-increasing level of accuracy. Yet, this comes at the cost of increased complexity. To deal with that problem, fitness trackers use derived metrics---scores calculated based on sensor data, e.g. a stress score. This means that part of the agency in interpreting health data is transferred from the user to the tracker. In this paper, we investigate the consequences of that transition and study how derived metrics can be designed to offer an optimal personal informatics experience. We conducted an online survey and a series of interviews which examined a health score (a hypothetical derived metric) at three levels of abstraction. We found that the medium abstraction level led to the highest level of reflection. Further, we determined that presenting the metric without contextual information led to decreased transparency and meaning. Our work contributes guidelines for designing effective derived metrics. https://dl.acm.org/doi/10.1145/35694752023MBMarit Bentvelzen et al.Fitness Tracking & Physical Activity MonitoringUbiComp
VR-Hiking: Physical Exertion Benefits Mindfulness and Positive Emotions in Virtual RealityExploring 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.2023LHLuke Haliburton et al.Social & Collaborative VRImmersion & Presence ResearchMobileHCI
[Don't] Let The Bodies HIIT The Floor: Fostering Body Awareness in Fast-Paced Physical Activity Using Body-Worn SensorsTechnologies 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.2023BEBettina Eska et al.Fitness Tracking & Physical Activity MonitoringBiosensors & Physiological MonitoringMobileHCI
Your Text Is Hard to Read: Facilitating Readability Awareness to Support Writing Proficiency in Text ProductionAllowing 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.2023JKJakob Karolus et al.Visualization Perception & CognitionGamification DesignDIS
EyePiano: Leveraging Gaze For Reflective Piano LearningMastering 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.2023JKJakob Karolus et al.Eye Tracking & Gaze InteractionSTEM Education & Science CommunicationDIS
Developing the Eudaimonic Technology Experience Scale 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.2023PWPaweł W. Woźniak et al.Workplace Wellbeing & Work StressDIS
VeatherReflect: Employing Weather as Qualitative Representation of Stress Data in Virtual RealityWhile 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, \black{}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.2023NWNadine Wagener et al.Immersion & Presence ResearchVisualization Perception & CognitionSleep & Stress MonitoringDIS
Literature Reviews in HCI: A Review of ReviewsThis 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.2023ESEvropi Stefanidi et al.University of BremenUser Research Methods (Interviews, Surveys, Observation)Research Ethics & Open ScienceCHI
The Walking Talking Stick: Understanding Automated Note-Taking in Walking MeetingsWhile 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 environments2023LHLuke Haliburton et al.LMU MunichCollaborative Learning & Peer TeachingContext-Aware ComputingHome Voice Assistant ExperienceCHI
Do You Mind? User Perceptions of Machine ConsciousnessThe 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.2023ASAva Elizabeth Scott et al.UCLAgent Personality & AnthropomorphismAI Ethics, Fairness & AccountabilityCHI
How Instructional Data Physicalization Fosters Reflection in Personal InformaticsThe 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.2023MBMarit Bentvelzen et al.Utrecht UniversityData PhysicalizationMental Health Apps & Online Support CommunitiesCHI
There Is No First- or Third-Person View in Virtual Reality: Understanding the Perspective ContinuumModern 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.2022MHMatthias Hoppe et al.LMU MunichImmersion & Presence ResearchIdentity & Avatars in XRCHI