Embracer: A Wearable Encountered-Type Haptic Controller for 3 DoF Input and FeedbackThe lack of haptic sensations beyond very simple vibration feedback diminishes the feeling of presence in Virtual Reality. Research suggested various approaches to deliver haptic sensations to the user's palm. However, these approaches are typically limited in the number of actuation directions and only focus on enhancing the system's output, ignoring haptic input. We present \systemname{}, a wrist-mounted encountered-type haptic controller that addresses these gaps by rendering forces along three axes through a sphere-shaped end effector within the user's palm. Using modified servo motors, we sense user-performed manipulations of the end effector as an input modality. In this paper, we contribute the design and implementation of \systemname{} together with a preliminary technical evaluation. By providing a more comprehensive haptic feedback system, \systemname{} enhances the realism and immersion of haptic feedback and user control.2024DDDennis Dietz et al.Force Feedback & Pseudo-Haptic WeightHaptic WearablesUbiComp
Queasy Rider: How Head Movements Influence Motion Sickness in Passenger Use of Head-Mounted DisplaysIn autonomous cars, drivers will spend more time on non-driving-related activities. Getting their hands off the wheel and eyes off the road, the driver, similar to a rear-seat passenger today, can use multiple built-in displays for such activities or even mobile head-mounted displays (HMDs) in virtual reality (VR). A wider motion range is known to increase engagement, but might also amplify the risk of motion sickness while switching between displays. In a rear-seat VR field study (N=21) on a city highway, we found a head movement range of ±50° with a speed of 1.95𝑚/𝑠 to provide the best trade-off between motion sickness and engagement. Compared to the pitch (Y) axis, movement around the yaw (X) axis induced less discomfort and more engagement with less motion sickness. Our work provides a concrete starting point for future research on self-driving carsickness, starting from today’s rear-seat passengers.2021JLJingyi Li et al.Motion Sickness & Passenger ExperienceImmersion & Presence ResearchAutoUI
A Journey Through Nature: Exploring Virtual Restorative Environments as a Means to Relax in Confined SpacesVirtual Reality (VR) technologies can counteract stress or fatigue and restore attention, e.g., by recreating the beauty of nature in a Virtual Restorative Environment (VRE). This has gained additional relevance in the current pandemic: When facing the stress of physical restrictions and a limited activity space, how can VR technologies provide the individual experience of being away? We created a VRE that can be used during trips in automated cars using a captured natural environment and simulated artifacts that communicate vehicle information during VR relaxation. In a user study (N=21), we compared the proposed in-car VRE to simply closing the eyes. We found that the VRE strongly improved the subjective ratings of mood and slightly increased attentional capacity and the objectively measured performance in a working memory test. Our results provide a concrete starting point for exploring calming VR experiences for future passengers, but also users at home.2021JLJingyi Li et al.Motion Sickness & Passenger ExperienceImmersion & Presence ResearchC&C
Do Touch This: Turning a Plaster Bust Into a Tangible InterfacePlaster busts are common exhibition pieces in museums, but they usually are off-limits for touch. While modern exhibition concepts increasingly involve interaction, this rarely includes touching a plaster bust. However, there may be a wealth of information associated with these cultural heritage objects, e.g., their making and their creator's craftsmanship, which tangible interaction could make accessible right on the object. We equipped plaster replicas of such a bust with capacitive sensors and developed a tangible prototype in collaboration with two domain experts from the art museum "Staatliche Antikensammlungen" (Munich, Germany), a curator and a sculptor, in an iterative design approach. Then we tested it in a lab study (N=12) and an in situ study in the museum (N=20). We describe our technical approach, which we also made public as a git project, and discuss our study results about busts as tangible interfaces in the art of sculpting.2021LHLinda Hirsch et al.Digital Art Installations & Interactive PerformanceMuseum & Cultural Heritage DigitizationC&C
I Think I Get Your Point, AI! The Illusion of Explanatory Depth in Explainable AIUnintended consequences of deployed AI systems fueled the call for more interpretability in AI systems. Often explainable AI (XAI) systems provide users with simplifying local explanations for individual predictions but leave it up to them to construct a global understanding of the model behavior. In this work, we examine if non-technical users of XAI fall for an illusion of explanatory depth when interpreting additive local explanations. We applied a mixed methods approach consisting of a moderated study with 40 participants and an unmoderated study with 107 crowd workers using a spreadsheet-like explanation interface based on the SHAP framework. We observed what non-technical users do to form their mental models of global AI model behavior from local explanations and how their perception of understanding changes when it is examined.2021MCMichael Chromik et al.Explainable AI (XAI)IUI
A Taxonomy of Vulnerable Road Users for HCI Based On A Systematic Literature ReviewRecent automotive research often focuses on automated driving, including the interaction between automated vehicles (AVs) and so-called "vulnerable road users" (VRUs). While road safety statistics and traffic psychology at least define VRUs as pedestrians, cyclists, and motorcyclists, many publications on human-vehicle interaction use the term without even defining it. The actual target group remains unclear. Since each group already poses a broad spectrum of research challenges, a one-fits-all solution seems unrealistic and inappropriate, and a much clearer differentiation is required. To foster clarity and comprehensibility, we propose a literature-based taxonomy providing a structured separation of (vulnerable) road users, designed to particularly (but not exclusively) support research on the communication between VRUs and AVs. It consists of two conceptual hierarchies and will help practitioners and researchers by providing a uniform and comparable set of terms needed for the design, implementation, and description of HCI applications.2021KHKai Holländer et al.LMU MunichExternal HMI (eHMI) — Communication with Pedestrians & CyclistsCHI
"You Have to Piece the Puzzle Together" – Implications for Designing Decision Support in Intensive CareIntensive Care Unit (ICU) professionals have to make lifesaving therapy decisions promptly under high stress and uncertainty. Clinical Decision Support Systems (CDSS) can improve the quality of healthcare by identifying complex statistical connections between patients' parameters and by rapidly presenting the statistically most promising treatment options to physicians. However, HCI aspects are rarely considered when developing CDSSs. This paper describes a field study conducted in three ICUs investigating how physicians and nurses form (volume) therapy decisions and monitor their success. Our findings reveal a continuous decision cycle in which nurses and physicians collaborate synchronously and asynchronously to provide optimal care. Furthermore, the desire to understand how a CDSS generated recommendations varies depending on the user's goals and other contextual factors such as workload. These findings show that CDSSs for ICUs need to (1) specifically facilitate collaboration and (2) support adaptation of the interface to both context and users.2020AKAnnika Kaltenhauser et al.AI-Assisted Decision-Making & AutomationMedical & Scientific Data VisualizationDIS
How to Trick AI: Users' Strategies for Protecting Themselves from Automatic Personality AssessmentPsychological targeting tries to influence and manipulate users' behaviour. We investigated whether users can protect themselves from being profiled by a chatbot, which automatically assesses users' personality. Participants interacted twice with the chatbot: (1) They chatted for 45 minutes in customer service scenarios and received their actual profile (baseline). (2) They then were asked to repeat the interaction and to disguise their personality by strategically tricking the chatbot into calculating a falsified profile. In interviews, participants mentioned 41 different strategies but could only apply a subset of them in the interaction. They were able to manipulate all Big Five personality dimensions by nearly 10%. Participants regarded personality as very sensitive data. As they found tricking the AI too exhaustive for everyday use, we reflect on opportunities for privacy protective designs in the context of personality-aware systems.2020SVSarah Theres Völkel et al.Ludwig Maximilian University of MunichPrivacy by Design & User ControlPrivacy Perception & Decision-MakingCHI
Communicating Uncertainty in Fertility PrognosisCommunicating uncertainty has been shown to provide positive effects on user understanding and decision-making. Surprisingly however, most personal health tracking applications fail to disclose the accuracy of their measurements and predictions. In the case of fertility tracking applications (FTAs), inaccurate predictions have already led to numerous unwanted pregnancies and law suits. However, integrating uncertainty into FTAs is challenging: Prediction accuracy is hard to understand and communicate, and its effect on users' trust and behavior is not well understood. We created a prototype for uncertainty visualizations for FTAs and evaluated it in a four-week field study with real users and their own data (N=9). Our results uncover far-reaching effects of communicating uncertainty: For example, users interpreted prediction accuracy as a proxy for their cycle health and as a security indicator for contraception. Displaying predicted and detected fertile phases next to each other helped users to understand uncertainty without negative emotional effects.2019HSHanna Schneider et al.Ludwig Maximilian University of MunichUncertainty VisualizationDiet Tracking & Nutrition ManagementCHI
Overtrust in External Cues of Automated Vehicles: An Experimental InvestigationThe intentions of an automated vehicle are hard to spot in the absence of eye contact with a driver or other established means of communication. External car displays have been proposed as a solution, but what if they malfunction or display misleading information? How will this influence pedestrians' trust in the vehicle? To investigate these questions, we conducted a between-subjects study in Virtual Reality (N = 18) in which one group was exposed to erroneous displays. Our results show that participants already started with a very high degree of trust. Incorrectly communicated information led to a strong decline in trust and perceived safety, but both recovered very quickly. This was also reflected in participants' road crossing behavior. We found that malfunctions of an external car display motivate users to ignore it and thereby aggravate the effects of overtrust. Therefore, we argue that the design of external communication should avoid misleading information and at the same time prevent the development of overtrust by design.2019KHKai Holländer et al.External HMI (eHMI) — Communication with Pedestrians & CyclistsAutoUI
A Bermuda Triangle? - A Review of Method Application and Triangulation in User Experience EvaluationUser experience (UX) evaluation is a growing field with diverse approaches. To understand the development since previous meta-review efforts, we conducted a state-of-the-art review of UX evaluation techniques with special attention to the triangulation between methods. We systematically selected and analyzed 100 papers from recent years and while we found an increase of relevant UX studies, we also saw a remaining overlap with pure usability evaluations. Positive trends include an increasing percentage of field rather than lab studies and a tendency to combine several methods in UX studies. Triangulation was applied in more than two thirds of the studies, and the most common method combination was questionnaires and interviews. Based on our analysis, we derive common patterns for triangulation in UX evaluation efforts. A critical discussion about existing approaches should help to obtain stronger results, especially when evaluating new technologies.2018IPIngrid Pettersson et al.Volvo Cars, Design and Human FactorsUser Research Methods (Interviews, Surveys, Observation)Prototyping & User TestingCHI
Empowerment in HCI - A Survey and FrameworkEmpowering people through technology is of increasing concern in the HCI community. However, there are different interpretations of empowerment, which diverge substantially. The same term thus describes an entire spectrum of research endeavours and goals. This conceptual unclarity hinders the development of a meaningful discourse and exchange. To better understand what empowerment means in our community, we reviewed 54 CHI full papers using the terms empower and empowerment. Based on our analysis and informed by prior writings on power and empowerment, we construct a framework that serves as a lens to analyze notions of empowerment in current HCI research. Finally, we discuss the implications of these notions of empowerment on approaches to technology design and offer recommendations for future work. With this analysis, we hope to add structure and terminological clarity to this growing and important facet of HCI research.2018HSHanna Schneider et al.LMU MunichEmpowerment of Marginalized GroupsTechnology Ethics & Critical HCICHI
Can a Helmet-mounted Display Make Motorcycling Safer?In this paper we investigated whether a helmet-mounted display for motorcyclists can provide similar benefits as the established in-car version: Head-up displays inform the driver efficiently and increase driving safety. In regard of their high safety risks, such a technology seems overdue for motorcyclists. Only recently, several crowdfunding projects raised substantial funding, however, none of them has led to commercial products yet. We developed an easy-to-reproduce and low-cost helmet-mounted display prototype and compared it with a conventional display setup. The helmet-mounted display was rated more attractive and induced a lower workload. Motorcyclists who generally exceeded the speed limit also rode significantly slower when using the head-mounted display. We argue that an intelligent application that adapts to the rider's behavior and preferences is the safest solution. We encourage other researchers to replicate our setup and to further investigate the impact of HUDs on the motorcyclists' behavior and road safety.2018RHRenate Haeuslschmid et al.Head-Up Display (HUD) & Advanced Driver Assistance Systems (ADAS)Motion Sickness & Passenger ExperienceIUI