注目の論文一覧

3D printing technology can be used to rapidly prototype the look and feel of 3D objects. However, the objects produced are passive. There has been increasing interest in making these objects interactive, yet they often require assembling components or complex calibration. In this paper, we contribute AirTouch, a technique that enables designers to fabricate touch-sensitive objects with minimal assembly and calibration using pneumatic sensing. AirTouch-enabled objects are 3D printed as a single structure using a consumer-level 3D printer. AirTouch uses pre-trained machine learning models to identify interactions with fabricated objects, meaning that there is no calibration required once the object has completed printing. We evaluate our technique using fabricated objects with various geometries and touch sensitive locations, obtaining accuracies of at least 90% with 12 interactive locations.

Sketchnoting is the process of creating a visual record with combined text and imagery of an event or presentation. Although analogue tools are still the most common method for sketchnoting, the use of digital tools is increasing. We conducted a study to better understand the current practices, techniques, compromises and opportunities of creating both pen&paper and digital sketchnotes. Our research combines insights from semi-structured interviews with the findings from a within-subjects observational study where ten participants created real time sketchnotes of two video presentations on both paper and digital tablet. We report our key findings, categorised into six themes: insights into sense of space; trade-offs with flexibility; choice paradox and cognitive load; matters of perception, accuracy and texture; issues around confidence; and practicalities. We discuss those findings, the potential and limitations of different methods, and implications for the design of future digital sketchnoting tools.

Participants in video meetings have long struggled with asymmetrical attention levels, especially when participants are distributed unevenly. While technological advances offer exciting opportunities to augment remote users' attention, the phenomenological complexity of attention means that to design attention-fostering features we must first understand what aspects of it are functionally meaningful to support. In this paper, we present a functional classification of observable attention for video meetings. The classification was informed by two studies on sense-making and selectiveness of attention in work meetings. It includes categories of attention accessible for technological support, their functions in a meeting process, and meeting-related activities that correspond to these functions. This classification serves as a multi-level representation of attention and informs the design of features aiming to support remote participants' attention in video meetings.

A Dark Pattern (DP) is an interface maliciously crafted to deceive users into performing actions they did not mean to do. In this work, we analyze Dark Patterns in 240 popular mobile apps and conduct an online experiment with 589 users on how they perceive Dark Patterns in such apps. The results of the analysis show that 95% of the analyzed apps contain one or more forms of Dark Patterns and, on average, popular applications include at least seven different types of deceiving interfaces. The online experiment shows that most users do not recognize Dark Patterns, but can perform better in recognizing malicious designs if informed on the issue. We discuss the impact of our work and what measures could be applied to alleviate the issue.

Haptic technology is maturing, with expectations and evidence that it will contribute to user experience (UX). However, we have very little understanding about how haptic technology can influence people's experience. Researchers and designers need a way to understand, communicate, and evaluate haptic technology's effect on UX. From a literature review and two studies – one with haptics novices, the other with expert hapticians – we developed a theoretical model of the factors that constitute a good haptic experience (HX). We define HX and propose its constituent factors: design parameters of Timeliness, Density, Intensity, and Timbre; the cross-cutting concern of Personalization; usability requirements of Utility, Causality, Consistency, and Saliency; and experiential factors of Harmony, Expressivity, Autotelics, Immersion, and Realism as guiding constructs important for haptic experience. This model will help guide design and research of haptic systems, inform language around haptics, and provide the basis for evaluative instruments, such as checklists, heuristics, or questionnaires.

Design thinking is an iterative, human-centered approach to innovation. Its success rests on collaboration within a multidisciplinary project team going through cycles of divergent and convergent ideations. In these teams, nondesigners risk diminishing the divergent reach because they are generally reluctant to sketch, thus missing out on theambiguous, imprecise early conceptual divergent phases. We hypothesized that LEGO^(®) could advantageously be a substitute to sketching. In this comparative study, 44 nondesigners randomly paired in 22 dyads did two conceptual ideations of healthcare landing pages, one using pen/paper (spontaneously writing words on sticky notes) and the other using LEGO, assessed through Torrance and Guilford frameworks for divergent thinking. Results show that LEGO interfaces gathered significantly higher divergent thinking scores because their concepts were significantly more elaborated. Furthermore, when using LEGO, teams who generated more elements were likely to also generate more ideas, more categories of ideas and more original ideas.

Sketching is a practical and useful skill that can benefit communication and problem solving. However, it remains a difficult skill to learn because of low confidence and motivation among students and limited availability for instruction and personalized feedback among teachers. There is an need to improve the educational experience for both groups, and we hypothesized that integrating technology could provide a variety of benefits. We designed and developed an intelligent tutoring system for sketching fundamentals called Sketchtivity, and deployed it in to six existing courses at the high school and university level during the 2017-2018 school year. 268 students used the tool and produced more than 116,000 sketches of basic primitives. We conducted semi-structured interviews with the six teachers who implemented the software, as well as nine students from a course where the tool was used extensively. Using grounded theory, we found ten categories which unveiled the benefits and limitations of integrating an intelligent tutoring system for sketching fundamentals in to existing pedagogy.

We explore a temperature illusion that uses low-powered electronics and enables the miniaturization of simple warm and cool sensations. Our illusion relies on the properties of certain scents, such as the coolness of mint or hotness of peppers. These odors trigger not only the olfactory bulb, but also the nose's trigeminal nerve, which has receptors that respond to both temperature and chemicals. To exploit this, we engineered a wearable device based on micropumps and an atomizer that emits up to three custom-made "thermal" scents directly to the user's nose. Breathing in these scents causes the user to feel warmer or cooler. We demonstrate how our device renders warmth and cooling sensations in virtual experiences. In our first study, we evaluated six candidate "thermal" scents. We found two hot-cold pairs, with one pair being less identifiable by odor. In our second study, pParticipants rated VR experiences with our device trigeminal stimulants as significantly warmer or cooler than the baseline conditions. Lastly, we believe this offers an alternative to existing thermal feedback devices, which unfortunately rely on power-hungry heat-lamps or Peltier-elements.

Given the prevalence and adverse impact of anxiety, there is considerable interest in using technology to regulate anxiety. Evaluating the efficacy of such technology in terms of both the average effect (the intervention efficacy) and the heterogeneous effect (for whom and in what context the intervention was effective) is of paramount importance. In this paper, we demonstrate the efficacy of PIV, a personalized breathing pacer, in reducing anxiety in the presence of a cognitive stressor. We also quantify the relation between our specific stressor and PIV-user engagement. To our knowledge, this is the first mixed-design study of a vibrotactile affect regulation technology which accounts for a specific stressor and for individual differences in relation to the technology's efficacy. Guidelines in this paper can be applied for designing and evaluating other affect regulation technologies.

E-textile microinteractions advance cord-based interfaces by enabling the simultaneous use of precise continuous control and casual discrete gestures. We leverage the recently introduced I/O Braid sensing architecture to enable a series of user studies and experiments which help design suitable interactions and a real-time gesture recognition pipeline. Informed by a gesture elicitation study with 36 participants, we developed a user-dependent classifier for eight discrete gestures with 94% accuracy for 12 participants. In a formal evaluation we show that we can enable precise manipulation with the same architecture. Our quantitative targeting experiment suggests that twisting is faster than existing headphone button controls and is comparable in speed to a capacitive touch surface. Qualitative interview feedback indicates a preference for I/O Braid's interaction over that of in-line headphone controls. Our applications demonstrate how continuous and discrete gestures can be combined to form new, integrated e-textile microinteraction techniques for real-time continuous control, discrete actions and mode switching.

APIs are becoming the fundamental building block of modern software and their usability is crucial to programming efficiency and software quality. Yet API designers find it hard to gather and interpret user feedback on their APIs. To close the gap, we interviewed 23 API designers from 6 companies and 11 open-source projects to understand their practices and needs. The primary way of gathering user feedback is through bug reports and peer reviews, as formal usability testing is prohibitively expensive to conduct in practice. Participants expressed a strong desire to gather real-world use cases and understand users' mental models, but there was a lack of tool support for such needs. In particular, participants were curious about where users got stuck, their workarounds, common mistakes, and unanticipated corner cases. We highlight several opportunities to address those unmet needs, including developing new mechanisms that systematically elicit users' mental models, building mining frameworks that identify recurring patterns beyond shallow statistics about API usage, and exploring alternative design choices made in similar libraries.

Despite the proliferation of platforms for social Virtual Reality (VR) communicating emotional expression via an avatar remains a significant design challenge. In order to better understand the design space for expressive Nonverbal Communication (NVC) in social VR we undertook an inventory of the ten most prominent social VR platforms. Our inventory identifies the dominant design strategies for movement, facial control, and gesture in commercial VR applications, and identifies opportunities and challenges for future design and research into social expression in VR. Specifically, we highlight the paucity of interaction paradigms for facial expression and the near nonexistence of meaningful control over ambient aspects of nonverbal communication such as posture, pose, and social status.

Households contain a variety of surfaces that are used in a number of activity contexts. As ambient technology becomes commonplace in our homes, it is only a matter of time before these surfaces become linked to computer systems for Household Surface Interaction (HSI). However, little is known about the user experience attached to HSI, and the potential acceptance of HSI within modern homes. To address this problem, we ran a mixed methods user study with 39 participants to examine HSI using nine household surfaces and five common gestures (tap, press, swipe, drag, and pinch). We found that under the right conditions, surfaces with some amount of texture can enhance HSI. Furthermore, perceived good and poor user experience varied among participants for surface type indicating individual preferences. We present findings and design considerations based on surface characteristics and the challenges that users perceive they may have with HSI within their homes.

Database management systems (or DBMSs) have been around for decades, and yet are still difficult to use, particularly when trying to identify and fix errors in user programs (or queries). We seek to understand what methods have been proposed to help people debug database queries, and whether these techniques have ultimately been adopted by DBMSs (and users). We conducted an interdisciplinary review of 112 papers and tools from the database, visualisation and HCI communities. To better understand whether academic and industry approaches are meeting the needs of users, we interviewed 20 database users (and some designers), and found surprising results. In particular, there seems to be a wide gulf between users' debugging strategies and the functionality implemented in existing DBMSs, as well as proposed in the literature. In response, we propose new design guidelines to help system designers to build features that more closely match users debugging strategies.

We propose generating two-dimensional skin stretch feedback on the user's legs. Skin stretch is useful cutaneous feedback to induce the perception of virtual textures and illusory forces and to deliver directional cues. This feedback has been applied to the head, body, and upper limbs to simulate rich physical properties in virtual reality (VR). However, how to expand the benefit of skin stretch feedback and apply it to the lower limbs, remains to be explored. Our first two psychophysical studies examined the minimum changes in skin stretch distance and stretch angle that are perceivable by participants. We then designed and implemented Gaiters, a pair of ungrounded, leg-worn devices, each of which is able to generate multiple two-dimensional skin stretches on the skin of the user's leg. With Gaiters, we conducted an exploratory study to understand participants' experiences when coupling skin stretch patterns with various lower limb actions. The results indicate that rich haptic experiences can be created by our prototype. Finally, a user evaluation indicates that participants enjoyed the experiences when using Gaiters and considered skin stretch as compelling haptic feedback on the legs.

Many people, especially those in sedentary occupations, fail to achieve the recommended levels of physical activity. Virtual reality (VR) games have the potential to overcome this because they are fun and also can be physically demanding. This paper explores whether a VR game studio can help workers in sedentary jobs to get valuable levels of exercise. We studied how 11 participants used our VR game studio in a sedentary workplace over 8-weeks and their perceptions of the experience. We analysed the physical exertion in the VR game studio, comparing this to their step counts from a smartwatch. All participants achieved valuable levels of physical activity and mood benefits. Importantly, for 6 participants, only with the VR game studio did they meet recommended activity levels. Our key contributions are insights about the use of a workplace VR game studio and its health benefits.

Social closeness is important for health and well-being, but is difficult to maintain over a distance. Games can help connect people by strengthening existing relationships or creating new ones through shared playful experiences. We present the design and evaluation of 'In the Same Boat' (ITSB), a two-player infinite runner designed to foster social closeness in distributed dyads. ITSB leverages the synchronization of both players' input to steer a canoe down a river and avoid obstacles. We created two versions: embodied controls, which use players' physiological signals (breath rate, facial expressions), and standard keyboard controls. Results from a study with 35 dyads indicate that ITSB fostered affiliation, and while embodied controls were less intuitive, people enjoyed them more. Further, photos of the dyads were rated as happier and closer in the embodied condition, indicating the potential of embodied controls to foster social closeness in synchronized play over a distance.

Personalization of eating such that everyone consumes only what they need allows improving our management of food waste. In this paper, we explore the use of food 3D printing to create perceptual illusions for controlling the level of perceived satiety given a defined amount of calories. We present FoodFab, a system that allows users to control their food intake through modifying a food's internal structure via two 3D printing parameters: infill pattern and infill density. In two experiments with a total of 30 participants, we studied the effect of these parameters on users' chewing time that is known to affect people's feeling of satiety. Our results show that we can indeed modify the chewing time by varying infill pattern and density, and thus control perceived satiety. Based on the results, we propose two computational models and integrate them into a user interface that simplifies the creation of personalized food structures.

We describe a Research-through-Design (RtD) project that explores the Internet of Things (IoT) as a resource for children's free play outdoors. Based on initial insights from a design ethnography, we developed four RtD prototypes for social play in different scenarios of use outdoors, including congregating on a street or in a park to play physical games with IoT. We observed these prototypes in use by children in their free play in two community settings, and report on the qualitative analysis of our fieldwork. Our findings highlight the designs' material qualities that encouraged social and physical play under certain conditions, suggesting social affordances that are central to the success of IoT designs for free play outdoors. We provide directions for future research that addresses the challenges faced when deploying IoT with children, contributing new considerations for interaction design with children in outdoor settings and free play contexts.

Quantitative persona creation (QPC) has tremendous potential, as HCI researchers and practitioners can leverage user data from online analytics and digital media platforms to better understand their users and customers. However, there is a lack of a systematic overview of the QPC methods and progress made, with no standard methodology or known best practices. To address this gap, we review 49 QPC research articles from 2005 to 2019. Results indicate three stages of QPC research: Emergence, Diversification, and Sophistication. Sharing resources, such as datasets, code, and algorithms, is crucial to achieving the next stage (Maturity). For practitioners, we provide guiding questions for assessing QPC readiness in organizations.

Participating in competitive races can be a thrilling experience for athletes, involving a rush of excitement and sensations of flow, achievement, and self-fulfilment. However, for non-athletes, the prospect of competition is often a scary one which affects intrinsic motivation negatively, especially for less fit, less competitive individuals. We propose a novel method making the positive racing experience accessible to non-athletes using a high-intensity cycling VR exergame: by recording and replaying all their previous gameplay sessions simultaneously, including a projected future performance, players can race against a crowd of "ghost" avatars representing their individual fitness journey. The experience stays relevant and exciting as every race adds a new competitor. A longitudinal study over four weeks and a cross-sectional study found that the new method improves physical performance, intrinsic motivation, and flow compared to a non-competitive exergame. Additionally, the longitudinal study provides insights into the longer-term effects of VR exergames.

Virtual Reality (VR) holds the promise of providing engaging embodied experiences, but little is known about how people with disabilities engage with it. We explore challenges and opportunities of VR gaming for wheelchair users. First, we present findings from a survey that received 25 responses and gives insights into wheelchair users' motives to (non-) engage with VR and their experiences. Drawing from this survey, we derive design implications which we tested through implementation and qualitative evaluation of three full-body VR game prototypes with 18 participants. Our results show that VR gaming engages wheelchair users, though nuanced consideration is required for the design of embodied immersive experiences for minority bodies, and we illustrate how designers can create meaningful, positive experiences.

Short online videos have become the dominating media on social platforms. However, finding suitable music to accompany videos can be a challenging task to some video creators, due to copyright constraints, limitations in search engines, and required audio-editing expertise. One possible solution to these problems is to use AI music generation. In this paper we present a user interface (UI) paradigm that allows users to input a song to an AI engine and then interactively regenerate and mix AI-generated music. To arrive at this design, we conducted user studies with a total of 104 video creators at several stages of our design and development process. User studies supported the effectiveness of our approach and provided valuable insights about human-AI interaction as well as the design and evaluation of mixed-initiative interfaces in creative practice.

The use of Virtual Reality (VR) in applications such as data analysis, artistic creation, and clinical settings requires high precision input. However, the current design of handheld controllers, where wrist rotation is the primary input approach, does not exploit the human fingers' capability for dexterous movements for high precision pointing and selection. To address this issue, we investigated the characteristics and potential of using a pen as a VR input device. We conducted two studies. The first examined which pen grip allowed the largest range of motion---we found a tripod grip at the rear end of the shaft met this criterion. The second study investigated target selection via 'poking' and ray-casting, where we found the pen grip outperformed the traditional wrist-based input in both cases. Finally, we demonstrate potential applications enabled by VR pen input and grip postures.

Connected devices present new opportunities to advance design through data collection in the wild, similar to the way digital services evolve through analytics. However, it is still unclear how live data transmitted by connected devices informs the design of these products, going beyond performance optimisation to support creative practices. Design can be enriched by data captured by connected devices, from usage logs to environmental sensors, and data about the devices and people around them. Through a series of workshops, this paper contributes industry and academia perspectives on the future of data-driven product design. We highlight HCI challenges, issues and implications, including sensemaking and the generation of design insight. We further challenge current notions of data-driven design and envision ways in which future HCI research can develop ways to work with data in the design process in a connected, rich, human manner.

Industrial design review is an iterative process which mainly relies on two steps involving many stakeholders: design discussion and CAD data adjustment. We investigate how a wall-sized display could be used to merge these two steps by allowing multidisciplinary collaborators to simultaneously generate and explore design alternatives. We designed ShapeCompare based on the feedback from a usability study. It enables multiple users to compute and distribute CAD data with touch interaction. To assess the benefit of the wall-sized display in such context, we ran a controlled experiment which aims to compare ShapeCompare with a visualization technique suitable for standard screens. The results show that pairs of participants performed a constraint solving task faster and used more deictic instructions with ShapeCompare. From these findings, we draw generic recommendations for collaborative exploration of alternatives.

Technologies targeting a correct execution of physical training exercises typically use pre-determined models for what they consider correct, automatizing instruction and feedback. This falls short on catering to diverse trainees and exercises. We explore an alternative design approach, in which technology provides open-ended feedback for trainers and trainees to use during training. With a personal trainer we designed the augmentation of 18 strength training exercises with BodyLights: 3D printed wearable projecting lights that augment body movement and orientation. To study them, 15 trainees at different skill levels trained three times with our personal trainer and BodyLights. Our findings show that BodyLights catered to a wide range of trainees and exercises, and supported understanding, executing and correcting diverse technique parameters. We discuss design features and methodological aspects that allowed this; and what open-ended feedback offered in comparison to current technology approaches to support training towards a correct exercise execution.

Users have long struggled to extract and repurpose data from websites by laboriously copying or scraping content from web pages. An alternative is to write scripts that pull data through APIs. This provides a cleaner way to access data than scraping; however, APIs are effortful for programmers and nigh-impossible for non-programmers to use. In this work, we empower users to access APIs without programming. We evolve a schema for declaratively specifying how to interact with a data API. We then develop ScrAPIr: a standard query GUI that enables users to fetch data through any API for which a specification exists, and a second GUI that lets users author and share the specification for a given API. From a lab evaluation, we find that even non-programmers can access APIs using ScrAPIr, while programmers can access APIs 3.8 times faster on average using ScrAPIr than using programming.

Tracking finger movement for natural interaction using hand is commonly studied. For vision-based implementations of finger tracking in virtual reality (VR) application, finger movement is occluded by a handheld device which is necessary for auxiliary input, thus tracking finger movement using cameras is still challenging. Finger tracking controllers using capacitive proximity sensors on the surface are starting to appear. However, research on estimating articulated hand pose from curved capacitance sensing electrodes is still immature. Therefore, we built a prototype with 62 electrodes and recorded training datasets using an optical tracking system. We have introduced 2.5D representation to apply convolutional neural network methods on a capacitive image of the curved surface, and two types of network architectures based on recent achievements in the computer vision field were evaluated with our dataset. We also implemented real-time interactive applications using the prototype and demonstrated the possibility of intuitive interaction using fingers in VR applications.

In tactile interaction, a phantom sensation refers to an illusion felt on the skin between two distant points at which vibrations are applied. It can improve the perceptual spatial resolution of tactile stimulation with a few tactors. All phantom sensations reported in the literature act on the skin or out of the body, but no such reports exist for those eliciting sensations penetrating the body. This paper addresses tactile phantom sensations in which two vibration actuators on the dorsal and palmar sides of the hand present an illusion of vibration passing through the hand. We also demonstrate similar tactile illusions for the torso. For optimal design, we conducted user studies while varying vibration frequency, envelope function, stimulus duration, and penetrating direction. Based on the results, we present design guidelines on penetrating phantom sensations for its use in immersive virtual reality applications.

We present the Skin-Stroke Display, a system mounted on the lens inside the head-mounted display, which exerts subtle yet recognizable tactile feedback on the eye-ring using a motorized air jet. To inform our design of noticeable air-jet haptic feedback, we conducted a user study to identify absolute detection thresholds. Our results show that the tactile sensation had different sensitivity around the eyes, and we determined a standard intensity (8 mbar) to prevent turbulent airflow blowing into the eyes. In the second study, we asked participants to adjust the intensity around the eye for equal sensation based on standard intensity. Next, we investigated the recognition of point and stroke stimuli with or without inducing cognitive load on eight directions on the eye-ring. Our longStroke stimulus can achieve an accuracy of 82.6% without cognitive load and 80.6% with cognitive load simulated by the Stroop test. Finally, we demonstrate example applications using the skin-stroke display as the off-screen indicator, tactile I/O progress display, and tactile display.

Kirigami Haptic Swatches demonstrate how kirigami and origami based structures enable sophisticated haptic feedback through simple cut-and-fold fabrication techniques. We leverage four types of geometric patterns: rotational erection system (RES), split-fold waterbomb (SFWB), the overlaid structure of SFWB and RES (SFWB+RES), and cylindrical origami, to render different sets of haptic feedback (i.e. linear, bistable, bouncing snap-through, and rotational force behaviors, respectively). In each structure, not only the form factor but also the force feedback properties can be tuned through geometric parameters. We experimentally analyzed and modeled the structures, and implemented software to automatically generate 2D patterns for desired haptic properties. We also demonstrate five example applications including an assistive custom keyboard, rotational switch, multi-sensory toy, task checklist, and phone accessories. We believe the Kirigami Haptic Swatches helps tinkerers, designers, and even researchers to create interactions that enrich our haptic experience.

Socially aware persuasive games that use immersive technologies often appeal to empathy, prompting users to feel and understand the struggles of another. However, the often sought-after 'standing in another's shoes' experience, in which users virtually inhabit another in distress, may complicate other-oriented empathy. Following a Research through Design approach, we designed for other-oriented empathy – focusing on a partaker-perspective and diegetic reflection – which resulted in Permanent; a virtual reality game designed to foster empathy towards evacuees from the 2011 Fukushima Daiichi nuclear disaster. We deployed Permanent 'in the wild' and carried out a qualitative study with 78 participants in the Netherlands and Japan to capture user experiences. Content Analysis of the data showed a predominance of other-oriented empathy across countries, and in our Thematic Analysis, we identified the themes of 'Spatial, Other, and Self -Awareness', 'Personal Accounts', 'Ambivalence', and 'Transdiegetic Items', resulting in design insights for fostering other-oriented empathy through virtual reality.

Influence of interaction fidelity and rendering quality on perceived user experience have been largely explored in Virtual Reality (VR). However, differences in interaction choices triggered by these rendering cues have not yet been explored. We present a study analysing the effect of thermal visual cues and contextual information on 50 participants' approach to grasp and move a virtual mug. This study comprises 3 different temperature cues (baseline empty, hot and cold) and 4 contextual representations; all embedded in a VR scenario. We evaluate 2 different hand representations (abstract and human) to assess grasp metrics. Results show temperature cues influenced grasp location, with the mug handle being predominantly grasped with a smaller grasp aperture for the hot condition, while the body and top were preferred for baseline and cold conditions.

Aggregate elements are ubiquitous in natural and man-made objects. Interactively authoring these elements with varying anisotropy and deformability can require high artistic skills and manual labor. To reduce input workload and enhance output quality, we present an autocomplete system that can help users distribute and align such elements over different domains. Through a brushing interface, users can place and mix a few elements, and let our system automatically populate more elements for the remaining output. Furthermore, aggregate elements often require proper direction/scalar fields for proper arrangements, but fully specifying such fields across entire domains can be difficult or inconvenient for ordinary users. To address this usability challenge, we formulate element fields that can smoothly orient all the elements based on partial user specifications without requiring full input fields in any step. We validate our prototype system with a pilot user study and show applications in design, collage, and modeling.

Crowd testing is an emerging practice in Graphical User Interface (GUI) testing, where developers recruit a large number of crowd testers to test GUI features. It is often easier and faster than a dedicated quality assurance team, and its output is more realistic than that of automated testing. However, crowds of testers working in parallel tend to focus on a small set of commonly-used User Interface (UI) navigation paths, which can lead to low test coverage and redundant effort. In this paper, we introduce two techniques to increase crowd testers' coverage: interactive event-flow graphs and GUI-level guidance. The interactive event-flow graphs track and aggregate every tester's interactions into a single directed graph that visualizes the cases that have already been explored. Crowd testers can interact with the graphs to find new navigation paths and increase the coverage of the created tests. We also use the graphs to augment the GUI (GUI-level guidance) to help testers avoid only exploring common paths. Our evaluation with 30 crowd testers on 11 different test pages shows that the techniques can help testers avoid redundant effort while also increasing untrained testers' coverage by 55%. These techniques can help us develop more robust software that works in more mission-critical settings not only by performing more thorough testing with the same effort that has been put in before but also by integrating them into different parts of the development pipeline to make more reliable software in the early development stage.

Humans rely on categories to mentally organize and understand sets of complex objects. One such set, haptic devices, has myriad technical attributes that affect user experience in complex ways. Seeking an effective navigation structure for a large online collection, we elicited expert mental categories for grounded force-feedback haptic devices: 18 experts (9 device creators, 9 interaction designers) reviewed, grouped, and described 75 devices according to their similarity in a custom card-sorting study. From the resulting quantitative and qualitative data, we identify prominent patterns of tagging versus binning, and we report 6 uber-attributes that the experts used to group the devices, favoring affordances over device specifications. Finally, we derive 7 device categories and 9 subcategories that reflect the imperfect yet semantic nature of the expert mental models. We visualize these device categories and similarities in the online haptic collection, and we offer insights for studying expert understanding of other human-centered technology.

One of the great benefits of virtual reality (VR) is the implementation of features that go beyond realism. Common "unrealistic" locomotion techniques (like teleportation) can avoid spatial limitation of tracking, but minimize potential benefits of more realistic techniques (e.g. walking). As an alternative that combines realistic physical movement with hyper-realistic virtual outcome, we present JumpVR, a jump-based locomotion augmentation technique that virtually scales users' physical jumps. In a user study (N=28), we show that jumping in VR (regardless of scaling) can significantly increase presence, motivation and immersion compared to teleportation, while largely not increasing simulator sickness. Further, participants reported higher immersion and motivation for most scaled jumping variants than forward-jumping. Our work shows the feasibility and benefits of jumping in VR and explores suitable parameters for its hyper-realistic scaling. We discuss design implications for VR experiences and research.

OR-constrained (ORC) graphical user interface layouts unify conventional constraint-based layouts with flow layouts, which enables the definition of flexible layouts that adapt to screens with different sizes, orientations, or aspect ratios with only a single layout specification. Unfortunately, solving ORC layouts with current solvers is time-consuming and the needed time increases exponentially with the number of widgets and constraints. To address this challenge, we propose ORCSolver, a novel solving technique for adaptive ORC layouts, based on a branch-and-bound approach with heuristic preprocessing. We demonstrate that ORCSolver simplifies ORC specifications at runtime and our approach can solve ORC layout specifications efficiently at near-interactive rates.

Input amplification enables easier movement in virtual reality (VR) for users with mobility issues or in confined spaces. However, current techniques either do not focus on maintaining feelings of body ownership, or are not applicable to general VR tasks. We investigate a general purpose non-linear transfer function that keeps the user's reach within reasonable bounds to maintain body ownership. The technique amplifies smaller movements from a user-definable neutral point into the expected larger movements using a configurable Hermite curve. Two experiments evaluate the approach. The first establishes that the technique has comparable performance to the state-of-the-art, increasing physical comfort while maintaining task performance and body ownership. The second explores the characteristics of the technique over a wide range of amplification levels. Using the combined results, design and implementation recommendations are provided with potential applications to related VR transfer functions.

Haptic feedback can significantly enhance the realism and immersiveness of virtual reality (VR) systems. In this paper, we propose MoveVR, a technique that enables realistic, multiform force feedback in VR leveraging commonplace cleaning robots. MoveVR can generate tension, resistance, impact and material rigidity force feedback with multiple levels of force intensity and directions. This is achieved by changing the robot's moving speed, rotation, position as well as the carried proxies. We demonstrated the feasibility and effectiveness of MoveVR through interactive VR gaming. In our quantitative and qualitative evaluation studies, participants found that MoveVR provides more realistic and enjoyable user experience when compared to commercially available haptic solutions such as vibrotactile haptic systems.

People often use videogames to restore wellbeing after negative experiences in day-to-day life. Although some research suggests that play can restore wellbeing, few studies have investigated the means by which restoration occurs. We employed self-determination theory (SDT) to understand how and to what degree play improves wellbeing after a need-frustrating event, and how players understand experiences of competence in play. Sixty-five participants worked at a competence manipulation task prior to playing a competence-satisfying videogame. Competence, affect, and vitality improved during play, and in-game experiences of need frustration were observed to effectively predict post-play negative affect. Post-experiment interviews indicate that videogames are seen to support competence relative to perceived skill, extending our knowledge of how design can support competence and restoration. We demonstrate that play can restore wellbeing, present need frustration as a means to explain negative experiences with interactive systems, and discuss effects of design on competence.

Somaesthetics — motivated by improving life quality via appreciation for bodily and sensory experiences — is increasingly influencing HCI designs. Investigating the potential of drones as a material for somaesthetic HCI, we designed Drone Chi: a Tai Chi-inspired close-range human-drone interaction experience. The design process for Drone Chi has been informed by the soma design approach and the Somaesthetic Appreciation concept from HCI literature. The artifact expands somaesthetic HCI by exemplifying dynamic and intimate somaesthetic interactions with a robotic design material, and body movements in expansive 3D space. To characterize the Drone Chi experience, we conducted an empirical study with 32 participants. Analysis of participant accounts revealed 4 themes that articulate different aspects of the experience: Looping Mental States, Environment, Agency vs. Control, and Physical Narratives. From these accounts and our craft knowledge, we derive 5 design implications to guide the development of movement-based close-range drone interactions.

Input techniques have been drawing abiding attention along with the continual miniaturization of personal computers. In this paper, we present BlyncSync, a novel multi-modal gesture set that leverages the synchronicity of touch and blink events to augment the input vocabulary of smartwatches with a rapid gesture, while at the same time, offers a solution to the false activation problem of blink-based input. BlyncSync contributes the concept of a mutual delimiter, where two modalities are used to jointly delimit the intention of each other's input. A study shows that BlyncSync is 33% faster than using a baseline input delimiter (physical smartwatch button), with only 150ms in overhead cost compared to traditional touch events. Furthermore, our data indicates that the gesture can be tuned to elicit a true positive rate of 97% and a false positive rate of 1.68%.

There is increased interest in reducing sedentary behavior of office workers to combat the negative health effects of prolonged sitting. Walking meetings offer a promising solution to this problem as they facilitate a physically active way of working. To inform future development of technologies supporting these type of meetings, in-depth qualitative insights into people's experiences of walking meetings are needed. We conducted semi-structured walking interviews (N=16) to identify key drivers and barriers for walking meetings in a living lab setting by using the 'WorkWalk'. The 'WorkWalk' is a 1.8 km walking route indicated by a dotted blue line with outdoor meeting points, integrated into the room booking system. Our findings provide insights into how walking meetings are experienced and affect the set-up and social dynamics of meetings. We offer design recommendations for the development of future technologies and service design elements to support walking meetings and active ways of working.

We present ShArc, a precision, geometric measurement technique for building multi-bend/shape sensors. ShArc sensors are made from flexible strips that can be dynamically formed into complex curves in a plane. They measure local curvature by noting the relative shift between the inner and outer layers of the sensor at many points and model shape as a series of connected arcs. Unlike jointed systems where angular errors sum with each joint measured, ShArc sensors do not accumulate angular error as more measurement points are added. This allows for inexpensive, robust sensors that can accurately model curves with multiple bends. To demonstrate the efficacy of this technique, we developed a capacitive ShArc sensor and evaluated its performance. We conclude with examples of how ShArc sensors can be employed in applications like gesture input devices, user interface controllers, human motion tracking and angular measurement of free-form objects.

Balance training has been shown to be effective in reducing risks of falling, which is a major concern for older adults. Usually, exercise programs are individually prescribed and monitored by physiotherapeutic or medical experts. Unfortunately, supervision and motivation of older adults during home-based exercises cannot be provided on a large scale, in particular, considering an ageing population. Augmented reality (AR) in combination with virtual coaches could provide a reasonable solution to this challenge.<br>We present a first investigation of the acceptance of an AR coaching system for balance training, which can be performed at home. In a human-centered design approach we developed several mock-ups and prototypes, and evaluated them with 76 older adults. The results suggest that older adults find the system encouraging and stimulating. The virtual coach is perceived as an alive, calm, intelligent, and friendly human. However, usability of the entire AR system showed a significant negative correlation with participants' age.

Substantial HCI research investigated the relationship between webpage complexity and aesthetics, but without a definitive conclusion. Some research showed an inverse linear correlation, some other showed an inverted u-shaped curve, while the rest showed no relationship at all. Such a lack of clarity complicates hypothesis formulation and result interpretation for future research, and lowers the reliability and generalizability of potential advice for Web design practice. We re-collected complexity and aesthetics ratings for five datasets previously used in webpage aesthetics and complexity research. The results were mixed, but suggested an inverse linear relationship with a weaker u-shaped sub-component. A subsequent visual inspection of revealed several confounding factors that may have led to the mixed results, including some webpages looking broken or archaic. The second data collection showed that accounting for these factors generally eliminates the u-shaped tendency of the complexity-aesthetics relationship, at least, for a relatively homogeneous sample of English-speaking participants.

Remote assistance represents an important use case for mixed reality. With the rise of handheld and wearable devices, remote assistance has become practical in the wild. However, spontaneous provisioning of remote assistance requires an easy, fast and robust approach for capturing and sharing of unprepared environments. In this work, we make a case for utilizing interactive light fields for remote assistance. We demonstrate the advantages of object representation using light fields over conventional geometric reconstruction. Moreover, we introduce an interaction method for quickly annotating light fields in 3D space without requiring surface geometry to anchor annotations. We present results from a user study demonstrating the effectiveness of our interaction techniques, and we provide feedback on the usability of our overall system.

Focusing on the person with advanced dementia as a social being presents a new opportunity for Experience-Centered Design (ECD), opening design to appreciate the agency and intentional actions of the person with advanced dementia. If Human-Computer Interaction is to shift from the predominantly assistive approach to a focus on experience, a theoretical framing that emphasizes the relational nature of selfhood is needed. In this article, we present Recognition Theory—a social theory based on an inter-subjectivist account of the struggle for recognition—to extend ECD approaches for advanced dementia. Focusing on people with advanced dementia, we examine recognition as a social and ethical perspective for establishing and maintaining self. We present a framework for design based on research with people with advanced dementia, experience-centered engagement and social identity, that will support designers to craft opportunities for mutual recognition in the design process and the practice of making.