Maintaining a certain heart rate zone is important for athletes during running. This is often supported by smartwatches or smartphones paired with chest belts. Such devices can easily distract or interrupt runners. To address this, we developed smart goggles with an integrated ambient LED strip that visually displays heart rate zone feedback. In a within-subject study (N=11), we compared the LED-Goggles and a state-of-the-art Apple Watch. The findings indicated no statistically significant difference in the efficacy of the two systems in assisting runners in maintaining their target heart rate. However, participants rated the goggles as clearer and more helpful than the watch. Open-ended responses highlighted the goggles’ continuous, ambient feedback as advantages, reducing cognitive load and allowing users to focus more on running. Our findings suggest that ambient light feedback in goggles can serve as an effective, less intrusive alternative to smart watch feedback systems for heart rate monitoring during runs.

Running is the most practiced sport worldwide. Locomotor-respiratory coupling (LRC) is a breathing technique claimed to enhance running economy and experience. Recent studies showed how sounds can guide runners in achieving and maintaining rhythmic breathing. This paper explores how runners can interact with the system to maintain control over the sonic breath guidance. The system enables runners to (1) reset the guidance when out of sync and (2) adjust the instructed rhythm based on their breath cycle and step count. Based on a user study (N=24), with participants running at +10% and -10% of baseline speed and at 2:2 and 3:3 LRC rhythms, we find that the proposed interactions are highly usable (SUS scores of 82 and 83 respectively) and a handheld button acceptable for most but disturbing for some. Sounds for guidance were highly effective (MAPE below 5%) across scenarios. We outline future steps for sonic guidance systems.

Running is the most practiced sport worldwide. Rhythmic breathing is a breathing technique claimed to enhance running economy and experience. Recent studies showed how sounds can guide runners in achieving and maintaining rhythmic breathing patterns. In this paper we explore how runners can interact with this sonic breath guidance while running, aiming to fit locomotion without forcing the runner to slow down or "stop-to-interact". Common devices, such as smartphones, smartwatches, and fitness trackers are widely employed, but their small interfaces and touch screens often necessitate slowing down for effective use. This demo paper introduces GestureGlove, a novel garment that captures fine and gross hand gestures to control rhythmic breathing guidance sounds. The concept combines gross arm gestures for sound selection by extending normal running motion, while fine in-hand gesturing enables fine-grained volume control of the selected sound independent of the running motion. These underlying principles of using gross and fine gesturing, and the embodied approach, show a new direction in the design for truly mobile interactions.

With the emergence of consumer-grade mobile Augmented Reality (AR) head-mounted displays (HMDs), it is increasingly important to study interaction modalities in mobile, outdoor contexts to explore user interactions under real-world conditions and ensure ecological validity. We present findings from a user study examining how state-of-the-art interaction techniques, originally developed for stationary indoor use, perform in outdoor walking contexts. We compare three techniques using a Fitts’ law task: (1) eye gaze for target selection combined with a pinch gesture for activation, (2) hand-controlled raycasting for selection with pinch activation, and (3) a go-go-hand-inspired technique that enables users to reach distant targets via virtual touch with a virtual hand representation. We report both performance metrics and subjective user feedback for these techniques.

We are delighted to present this special issue of Behaviour & Information Technology (BIT), featuring extended versions of a selection of the best papers presented at the 18th International Confere...

Abstract Augmented reality revolutionizes the way individuals interact with urban environments, fostering novel collaborative modalities in public space design. Our study introduces 'City Craft', an augmented reality application which empowers users to create and modify urban layouts by selecting, positioning, and editing 3D models collaboratively. We detail the deployment of City Craft in two field studies with 33 participants, where the application was used in public space. Results indicate that when participants were paired on a single device, collaboration was synchronous and involved shared control, whereas larger groups engaged more asynchronously. The consensus among participants is that City Craft invites a new perspective on public space, fosters creativity and a collaborative mindset. We argue in situ use of AR tools such as City Craft increases interest in participating in urban design and can aggregate different views on public space use, which can be further refined collectively. However, City Craft should be complemented with a mix of digital and analog tools across the different stages of the design process.

Even though recent technological advancements have led to a growing interest in Augmented Reality (AR) head-mounted displays (HMDs), their actual deployment in everyday, outdoor and on-the-move applications remains uncertain. Most AR research is conducted in controlled laboratory settings, leaving a gap in our understanding of AR’s potentials and complexities in real-world environments. This paper explores the social aspects surrounding AR use in public spaces, by investigating the use of AR HMDs during two distinct use cases: shopping at a farmers market and outdoor presentations. Based on the analysis of observations and interviews with participants, passersby and vendors, we explore social impact of AR and share methodological and technological insights. We contribute seven lessons learned for researchers conducting AR studies in-the-wild. Our findings show that the current understanding of non-users should be revisited for in-the-wild AR studies. Furthermore, current AR HMDs lack social components, inducing awkwardness in social situations, which might fade with continuous exposure.

Cardiovascular diseases (CVDs) are a major global health challenge, compounded by a significant systemic treatment gap: the underutilization of cardiac rehabilitation (CR). Central to this issue is the crucial yet underperforming referral process to CR due to various factors, including patients’ lack of information. By co-designing a CR referral assistant with cardiac patients and healthcare professionals, this work explores how technology can support patient journeys from the acute hospital to CR, overcoming existing healthcare system barriers. This work (1) contributes a map of patients’ evolving needs tailored to their pathway, (2) provides design implications for interactive digital health technologies aiming to facilitate patient transitions across established healthcare system boundaries, and (3) discusses the potential of technology as a “patient companion” during their transition to CR.

Due to the continuous improvement of Augmented Reality (AR) head-mounted displays (HMDs), these devices are bound to be increasingly integrated into our daily routines. So far, a major focus of AR research has been on indoor usage and deployment. However, since seamlessly supporting users in their activities while being on-the-move in various outdoor contexts becomes increasingly important, there is a need to investigate the current state-of-the-art of AR technologies while people are in motion outdoors. Therefore, we conducted a systematic literature review of pertinent HCI publications, specifically looking into applications concerning vulnerable road users. We identify the contexts in which such technologies have been researched, prevailing challenges in the field, and applied methodological approaches. Our findings show that most contributions address pedestrians, a shift towards HMDs, and a prevalence of lab studies due to technology limitations. Based on our findings, we discuss trends, existing gaps and opportunities for future research.

The assessment of source code in university education is a central and important task for lecturers of programming courses. In doing so, educators are confronted with growing numbers of students having increasingly diverse prerequisites, a shortage of tutors, and highly dynamic learning objectives. To support lecturers in meeting these challenges, the use of automated programming assessment systems (APASs), facilitating formative assessments by providing timely, objective feedback, is a promising solution. Measuring the effectiveness and success of these platforms is crucial to understanding how such platforms should be designed, implemented, and used. However, research and practice lack a common understanding of aspects influencing the success of APASs. To address these issues, we have devised a success model for APASs based on established models from information systems as well as blended learning research and conducted an online survey with 414 students using the same APAS. In addition, we examined the role of mediators intervening between technology-, system- or self-related factors, respectively, and the users' satisfaction with APASs. Ultimately, our research has yielded a model of success comprising seven constructs influencing user satisfaction with an APAS.

Abstract Driving an automated vehicle requires a clear understanding of its automation capabilities and resulting duties on the driver’s side. This is true across all levels of automation but especially so on SAE levels 3 and below, where the driver has an active driving task performance and/or monitoring role. If the automation capabilities and a driver’s understanding of them do not match, misuse can occur, resulting in decreased safety. In this paper, we present the results from a simulator study that investigated driving mode awareness support via ambient lights across automation levels 0, 2, and 3. We found lights in the steering wheel to be useful for momentary and lights below the windshield for permanent indication of automation-relevant information, whereas lights in the footwell showed to have little to no positive effects on driving mode awareness.

In mixed traffic environments, highly automated vehicles (HAV) can potentially be disruptive and a source of hazards due to their non-human driving behavior and a lack of “traditional” communication means (gestures, eye contact, and similar) to resolve issues or otherwise unclear situations. As a result, additional external human-machine interfaces (eHMI) for automated vehicles that replace the now absent human element in communication have been proposed. In this paper, we present the results from a study, in which two versions of a light band eHMI to communicate driving intend of an automated shuttle were evaluated in a real driving environment. We found that the green-red traffic light metaphor and simple animations could improve interaction success in certain aspects. We also found and discuss that the effect of using vs. not using the visual eHMIs was overall lower than expected and that the shuttle’s position and observable driving behavior seemed to play a larger role than anticipated.

With increasing automation capabilities and a push towards full automation in vehicles, mode awareness, i.e., the driver’s awareness of the vehicle’s current automation mode, becomes an important factor. While issues surrounding mode awareness are known, research concerning and design towards mode awareness appears to not yet be a focal point in the automated driving domain. In this paper, we provide a state-of-the art on mode awareness from the related domains of automated driving, aviation, and Human-Robot Interaction. We present a summary of existing mode awareness interface solutions as well as existing techniques and recognized gaps concerning mode awareness. We found that existing interfaces are often simple, sometimes outdated, yet are difficult to meaningfully expand without overloading the user. We also found predictive approaches as a promising strategy to lessen the need for mode awareness via separate indicators.

Driverless shuttles bear different and novel challenges for passengers. One of these is related to capacity management, as such shuttles are often smaller (usually from 6 to 12 seats) with limited capacities to (re-)assign seating, control reservations, or arrange travels for groups that exceed a shuttle’s capacity. Since a bus driver is missing, passengers need to resolve conflicts or uncertainties on their own, unless additional systems provide such support. In this paper, we present the results from a laboratory study, in which we investigated passenger needs in relation to booking and reserving spots (seats, standing spots, and strollers) in an automated shuttle. We found that such functionalities have a low-to-medium impact on an overall scale but could constitute exclusion criteria for more vulnerable parts of the population, such as older adults, families with small children, or physically impaired individuals.

LEDs on a strip, when turned on and off in a specific order, result in the perception of apparent motion (i.e. beta movement). In the automotive domain such chase lights have been used to alter drivers' perception of driving speed by manipulating the pixel speed of LEDs. We argue that the perceived velocity of beta movement in the peripheral view is not only based on the actual pixel speed but can be influenced by other factors such as frequency, width and brightness of lit LED segments. We conducted a velocity matching experiment (N=25) by systematically varying these three properties, in order to determine their influence on a participant's perceived velocity in a vehicle mock-up. Results show that a higher frequency and stronger brightness increased perceived velocity, whereas segment width had no influence. We discuss how findings may be applied when designing systems that use beta movement to influence the perception of ambient light velocity.

Abstract The absence of a human driver creates novel challenges for fully automated public transport. Passengers are likely to have different expectations, needs, or even fears when traveling without a driver in potentially dangerous situations. We present the results from two field studies in which we explored incident management in a driverless shuttle bus. We explored participant’s behavior and willingness to assist in solving problems in a variety of scenarios where the bus suddenly stops for technical reasons or a hypothesized situation of harassment. In a follow-up study, we focused on auditory remote assistance and investigated problem solving through the passengers. We found that diffusion of responsibility is an existent barrier, when passengers are involved in the resolving of potentially dangerous situations. It can be overcome, when incident-relevant instructions are designed explicitly, briefly, timely, distinguishable from regular on-trip information, and address auditory and visual sensory channels alike.

Advanced Driver Assistance Systems (ADAS) aim to increase safety by supporting drivers in the driving task. Especially older drivers (65+ years), given the nature of aging, could benefit from these systems. However, little is known about older drivers' acceptance of ADAS in general and how particular acceptance aspects influence their intention to use such systems. To address this research gap, we present results from a large-scale online survey (n=1328) with aging drivers, which was conducted in three European countries in 2019. We identified several demographic and driving-related variables, which are significantly related to acceptance. Furthermore, we found that older drivers' intention to use ADAS is most strongly predicted by favorable acceptance aspects (i.e., usefulness, reassurance, and trust), while unfavorable aspects (i.e., annoyance, irritation, and stress) were found to have less to none predictive power. The findings are discussed considering future research directions in this area.

Riding a highly automated bus has the potential to bring about a set of novel challenges for the passenger. As there is no human driver present, there is no one to talk to regarding driving direction, stops, or delays. This lack of a human element is likely to cause a stronger reliance on the in-vehicle means of communication, such as displays. In this paper, we present the results from a qualitative study, in which we tested three different on-screen visualizations for passenger information during an automated bus trip. The designs focused primarily on signaling the next stop and proper time to request the bus to stop in absence of a human driver. We found that adding geo-spatial details can easily confuse more than help and that the absence of a human driver makes passengers feel more insecure about being able to exit at the right stop. Thus, passengers are less receptive for visual cues signaling upcoming stops and more likely to input stop requests immediately upon leaving the station.

In light of recent incidents, it has become increasingly relevant to determine who is responsible in case of accidents involving automated vehicles. In this paper, we investigate the question of liability in automated vehicles of SAE levels 3 and above. We claim that there is a mismatch between current liability practices, where a designated driver is usually held responsible, and future perspectives, where the human assumes more and more a passive passenger-like role. Our claims are supported by the results from an interview study with insurance companies from two European countries. We show that insurers lack sufficient data to make informed decisions on how to apportion liability in SAE level 3+ scenarios. We discuss how these considerations have to be reflected in interfaces for the driver in order to make the legal status transparent for the driver.

Automated vehicles have to make decisions, such as driving maneuvers or rerouting, based on environment data and decision algorithms. There is a question whether ethical aspects should be considered in these algorithms. When all available decisions within a situation have fatal consequences, this leads to a dilemma. Contemporary discourse surrounding this issue is dominated by the trolley problem, a specific version of such a dilemma. Based on an outline of its origins, we discuss the trolley problem and its viability to help solve the questions regarding ethical decision making in automated vehicles. We show that the trolley problem serves several important functions but is an ill-suited benchmark for the success or failure of an automated algorithm. We argue that research and design should focus on avoiding trolley-like problems at all rather than trying to solve an unsolvable dilemma and discuss alternative approaches on how to feasibly address ethical issues in automated agents.

Once highly automated vehicles become available, drivers will be freed to perform activities other than driving when automated driving mode is activated. Such activities could include relaxing, reading, exercising, or working. The work of professional drivers such as truck drivers can be expected to be especially affected by this technology and to change accordingly as highly automated trucks enable the completion of other working related tasks during automated driving. But will such mobile working places be accepted by truck drivers? In this paper, we report on a survey (N=23) assessing technology acceptance towards Future Workplaces in highly Automated Trucks (FWAT). Results show that a majority of drivers is rather skeptical about FWAT, but that acceptance can be expected to strongly vary. Our paper provides some guidance on how to explain this variance and presents relevant acceptance factors for future FWAT usage.

Current research on Vehicle-to-Vehicle (V2V) communication aims at improving interaction between different vehicles by communication technologies and is mainly focused on driver-to-driver interaction. But how do drivers and passengers of two vehicles that have the same destination communicate with each other? In such a collaborative driving scenario, several factors such as the environmental context or the behavior of the vehicle occupants may influence the communication. In order to explore how information is exchanged in collaborative driving, we conducted an exploratory in-situ study with seven groups of two driver/co-driver pairs each, located in two separate vehicles. During the ride, the participants had to drive collaboratively on a predefined route solving different subtasks. We found that different social (e.g., driving habits, unpredicted intentions) and contextual factors (e.g., night/rain conditions, size or color of the vehicle) influenced collaboration. Our findings provide a deeper understanding of collaborative driving and inform future V2V communication designs.

In modern traffic, measures are implemented to regulate speeding, which may annoy drivers who pursue an exciting driving experience and make them exceed speed limits. Others prefer a more relaxing experience resulting in socially desired driving behavior. This paper presents a study investigating the capacity of ambient light to alter the perception of speed and therefore influence the driving experience. The aim of this study was to determine how different drivers experience the concept of an ambient light moving along the a-pillar inside the vehicle. In different conditions, the light moved at different speeds. The outcomes of the study show that overall the ambient light used in this study had a positive effect on the driving experience but that the attitude towards the ambient light was highly individual. The majority indicated a preference towards the ambient light while some saw it more as a distraction or even inducing more stress.

Designing safe and effective systems for control transitions between human and vehicle is a difficult task, due to increased reaction times and potentially inattentive drivers. In order to respond to these difficulties, this paper presents an overview of interaction solutions for control transitions between manual and autonomous driving modes. The paper examines technology patents, as well as academic publications. The paper's first contribution is an examination of the current state of the art of control transition interfaces in automated vehicles. The paper's second contribution is the reusable categorization framework developed for this overview. The results are used to identify holes and potentials regarding control transition design, including strong focus on the system over the human, lacking fallback performance, and the potentials of effective driving mode communication. These aspects point the way towards the challenges to be solved -- together with how they might be solved -- for safe and effective control transitions.

LED visualizations in the car are primarily used to direct the driver's attention to obstacles or hazards in the environment. An ambient LED arrangement can indicate the horizontal position of outside objects without obstructing the driver's field of view. How accurately the LEDs represent the spatial position of an outside object and how well it can be distinguished from other nearby objects is influenced by several factors. Our aim is to increase the spatial accuracy of a windshield-mounted horizontal LED visualization. Our approach is to use a calibration procedure to increase this accuracy. In an experimental study in our driving simulator, we found that calibration increased the spatial accuracy and, as a result, the recognition reliability (in our setup from 67% to 95%) and that a 3-point calibration is sufficient in comparison to more calibration points.

In aviation, pilots interact with autopilots almost on a daily basis. With semi-autonomous vehicles, this is not yet the case. In our work, we aimed at finding out what we can learn from pilots' current experiences for the domain of autonomous driving and what implications can be derived. We conducted three in-depth interviews with pilots to investigate how pilots currently handle handover situations to and from the autopilot, which information is relevant for this transition to be successful, how pilots react in critical situations, how handovers are trained, and how flying and handover skills are maintained. We compare the gained insights with the domain of autonomous driving and reflect on implications for handovers and (de)skilling. Our findings suggest that the AUI community can learn from aviation in areas such as situation awareness, transparency of system status, the need for a primary drive display, calibrated (dis)trust, and driver training.

The rise of autonomous and fully autonomous vehicles requires a closer examination of how people will interact with them. In this workshop, we especially address two areas: (1) What can we learn from mobile HCI for the interaction design between human drivers and the autonomous vehicle? (2) What opportunities for mobile HCI arise due to new freedoms for drivers, when they also take on the role of passengers in autonomous vehicles? The workshop will seek to further develop the challenges involved and/or to suggest early solutions through the use of a highly participative format.

We present active corners, a novel interaction approach for in-car collaboration that maps the spatial arrangement of a car with up to four people (i.e., driver, front seat passenger, and two rear seat passengers) to the form factor of a tablet (i.e., having 4 corners). We use this mental model to allow the driver and passengers to collaborate with each other. Interaction is done by dragging-and-dropping items into the according corners of individual tablets. We present the basic interaction design concept along with three application scenarios. In order to evaluate active corners, we have implemented a multiplayer card game that exploits the proposed interaction concept and fosters collaboration. We report on four field studies in which we evaluated different aspects of the active corners concept. Results show that the interaction approach is intuitive and provides a high usability even in driving conditions.

This paper proposes a taxonomy of autonomous vehicle handover situations with a particular emphasis on situational awareness. It focuses on a number of research challenges such as: legal responsibility, the situational awareness level of the driver and the vehicle, the knowledge the vehicle must have of the driver's driving skills as well as the in-vehicle context. The taxonomy acts as a starting point for researchers and practitioners to frame the discussion on this complex problem.

The distraction potential of communication systems in the automotive context necessitates hands-free and attention undemanding systems. Today's hands-free car kits are of increasingly high quality, since bad audio quality can negatively impact the overall communication quality. Most solutions use built-in speakers for output and a microphone near the driver (e.g. on the ceiling). Thereby, audio quality can suffer e.g. from the long distance between the speaker and the listener. In a recent study, we compared perceived voice quality and social presence of a prototype with speakers installed in the headrest of a vehicle, to a high-end on-board audio system in a communication situation between a person sitting in the driver's seat and a person outside the vehicle. We found that Personal Audio received generally better results while also introducing its own set of issues, e.g., causing spatial disorientation in communication situations, in which other individuals are present in the car.

In the scope of autonomous driving, the question arises if the increased use of automated systems will have an impact on driver's skills in handling the car in the long term. In order to gain more insights on the issue of driver deskilling and how it relates to driving experience and time intervals of non-driving, we conducted an online survey (n=703) considering three driver groups. We found that initial skilling is more of an issue than deskilling after long periods of driving inactivity, i.e., while once learned driving skills seem to remain stable after longer periods of non-driving, they are much more influenced by driving experience in terms of annual mileage and frequency of use. Applied to the autonomous context, this means that drivers must be trained to a high enough skill level or require sufficient manual driving experience, in order to be able to react properly when driving themselves.

Interaction environments are characterized by their spatial properties, which guide, direct, and provide an opportunity to become a place for social encounters. For example, the car cabin comprises properties such as a special seating arrangement and hence physical barriers between the back and front row. In emphasizing notions of "space" and "place", we present an initial study on how such spatial properties of the car cabin shape passenger collaboration. With this, we contribute to a better understanding of the automotive design space beyond driver and co-driver positions. In an exploratory lab study with 56 participants we observed collaborative practices in a hardware mock-up of an actual car. We found that social practices in cars need to be understood as connected to their inherent spatial manifestations, which are constraining and concurrently constituting them. We reflect upon the driver position as "the crux of the matter", the meanings people ascribe to particular positions, and how we can use this knowledge to inform automotive interaction design.

Combining touch screen technology with mid-air gestures into a unified input modality has potential to improve interaction with touch interfaces in cars. Moreover, target objects on a touch screen can be adapted to the proximity of a users' finger in mid-air. In this paper, we present an exploration of this design space based on two studies and various prototypical systems. First, results of a driving simulator study are reported, indicating that a driver's performance in acquiring a target object on a touch screen in a central console position increases with expanding targets, while altering the position of a target object on the screen leads to a decrease of performance. In a follow-up workshop with automotive experts, prototypes with multiple expanding targets were utilized to foster in-depth discussions on potential challenges and benefits with expanding targets in cars. Results of both studies indicate a high potential of expanding targets for in-car interaction scenarios.

For the automotive domain shape-changing interfaces hold potential as an interaction modality since they offer modalities that do not rely on the driver's vision such as traditional screen-based interfaces. In this paper we present a shape-changing car-seat backrest that lets the driver haptically sense obstacles in the rear periphery. We implemented a prototype with a 4 × 4 array of servomotors that changes the shape of the car-seat backrest. In comparison to other approaches that often use the seat for vibro-cues or warnings signals, our approach delivers a continuous dorsal sensory augmentation of the rear periphery. The prototype was studied for its capability on transporting spatial information haptically in a pilot study with 10 participants. The lab study revealed that the interface is able to induce sensory augmentation. Most of the participants were able to spatially locate the stimuli.

In order to support drivers to maintain a predefined driving speed, we introduce ChaseLight, an in-car system that uses a programmable LED stripe mounted along the A-pillar of a car. The chase light (i.e., stripes of adjacent LEDs that are turned on and off frequently to give the illusion of lights moving along the stripe) provides ambient feedback to the driver about speed. We present a simulator based user study that uses three different types of feedback: (1) chase light with constant speed, (2) with proportional speed (i.e., chase light speed correlates with vehicle speed), and (3) with adaptive speed (i.e., chase light speed adapts to a target speed of the vehicle). Our results show that the adaptive condition is suited best to help a driver to control driving speed. The proportional speed condition resulted in a significantly slower mean speed than the baseline condition (no chase light).

In-car navigation systems typically have the purpose to support the driver in a navigation task. While the field of automotive HCI research abounds in driver-focused navigation design relatively little attention has been directed to the front-seat passengers as a support to the driver for e.g., navigation. Based on our ethnographic research, we have designed and prototyped a system called Co-Navigator. It was devised to be operated by the front-seat passenger, in order to support the driver in navigation and driving related tasks. The Co-Navigator is an interactive, tablet based navigation app that provides different kinds of information such as landmarks and upcoming hazard warnings (e.g., construction sites or potholes). In this paper, we describe the prototype, its elements, and an explorative in-situ evaluation. Results show that the Co-Navigator is a valuable in-car navigation device for the front-seat passenger. Especially the map overview and hazard warnings were appreciated.

In demanding driving situations, the front-seat passenger can become a supporter of the driver by, e.g., monitoring the scene or providing hints about upcoming hazards or turning points. A fast and efficient communication of such spatial information can help the driver to react properly, with more foresight. As shown in previous research, this spatial referencing can be facilitated by providing the driver a visualization of the front-seat passenger's gaze. In this paper, we focus on the question how the gaze should be visualized for the driver, taking into account the feasibility of implementation in a real car. We present the results from a driving simulator study, where we compared an LED visualization (glowing LEDs on an LED stripe mounted at the bottom of the windshield, indicating the horizontal position of the gaze) with a visualization of the gaze as a dot in the simulated environment. Our results show that LED visualization comes with benefits with regard to driver distraction but also bears disadvantages with regard to accuracy and control for the front-seat passenger.

This paper presents a design exploration of full-body interaction games played in cars. It describes how we have designed, implemented, and evaluated the core experiences of three different games, which were all aimed at making sitting properly more fun for players/children while travelling by car. By making the restricted body an integral part of gameplay, we hope to, as a side product of gameplay, bring about the best and also most safe body posture for young players/children travelling by car, i.e., sitting reasonably upright and still in their child seat with their head leaning back on the neck rest. Another outcome of this could also be an overall safer situation in the car, in that children not sitting still in their child seats while being driven might be stressful for the driver. By presenting the details of our design efforts in this particular design context, we hope to add also to the knowledge we, in HCI, have for how to design bodily experiences with technology at large.

In order to envision novel in-car user interfaces, it is important to investigate driver and passenger behavior as well as to identify relevant context factors that influence this behavior. Automotive user interfaces are often concentrated on drivers and their needs, whereas passengers and their needs are paid little attention to. In this paper we report on a probing study, which aimed at revealing novel design ideas for interfaces for both, car drivers and passengers. The overall goal of the study was to get inspired by actual driver and passenger behavior. In particular, we investigated past behaviors and what we can learn from these episodes for automotive interface design. We illustrate the user-centered process of generating innovative design concepts for the automotive domain based on the results of the probing study. Additionally, we introduce three resulting design concepts by means of design sketches and textual descriptions to provide insights on the concrete results of our efforts. We discuss probing as a method to generate novel design ideas for the automotive UI community and reflect on the three emerged design concepts which focus on collaboration, behavior change, and entertainment in the car.

Surveys [8] show that people generally have a positive attitude towards autonomous cars. However, these studies neglect that cars have different levels of autonomy and that User Acceptance (UA) and User Experience (UX) with autonomous systems differ with regard to the degree of system autonomy. The National Highway Traffic Safety Administration (NHTSA) defines five degrees of car autonomy which vary in the penetration of cars with Advanced Driver Assistance Systems (ADAS) and the extent to which a car is taken over by autonomous systems. Based on these levels, we conducted an online-questionnaire study (N = 336), in which we investigated how UA and UX factors, such as Perceived Ease of Use, Attitude Towards using the system, Perceived Behavioral Control, Behavioral Intention to use a system, Trust and Fun, differ with regard to the degree of autonomy in cars. We show that UA and UX are highest in levels of autonomy that already have been deployed in modern cars. More specifically, perceived control and fun decrease continuously with higher autonomy. Furthermore, our results indicate that pre-experience with ADAS and demographics, such as age and gender, have an influence on UA and UX.

This paper addresses the phenomenon of emotional attachments to mobile phones. We introduce the term "mobile attachment" and define it as a bond between a person's self and a mobile phone that varies in strength. Based on a critical reflection of interdisciplinary literature, a conceptual mobile attachment model is developed. Within this model causes, consequences and influencing factors of mobile attachment are exposed and elaborated. We argue that mobile attachment emerges when the mobile phone becomes part of the user's self concept. The link between the user and their mobile phone may be fostered when it empowers, enriches, or gratifies the user's self. Attachment causes lead to "design space determinants" that enable user experience designers to design for mobile attachment. Attachment consequences may be operationalized for user experience evaluation.

Authentication based on touch-less mid-air gestures would benefit a multitude of ubicomp applications, which are used in clean environments (e.g., medical environments or clean rooms). In order to explore the potential of mid-air gestures for novel authentication approaches, we performed a series of studies and design experiments. First, we collected data from more then 200 users during a three-day science event organised within a shopping mall. This data was used to investigate capabilities of the Leap Motion sensor and to formulate an initial design problem. The design problem, as well as the design of mid-air gestures for authentication purposes, were iterated in subsequent design activities. In a final study with 13 participants, we evaluated two mid-air gestures for authentication purposes in different situations, including different body positions. Our results highlight a need for different mid-air gestures for differing situations and carefully chosen constraints for mid-air gestures.

User Experience (UX) studies in the automotive context are essential for a good interaction design in the car. But there is a lack of appropriate methods to investigate the user's experience in-situ in a natural setting. In this paper we introduce computerized experience sampling in the car. We present an ESM tool based on the OBD-II interface of a car in combination with an android smartphone and describe issues and challenges we experienced while applying our tool in an initial UX study.

Automobiles are environments rich of data that have a high potential to be used as input for research and design. Various difficulties accessing car data exclude HCI experts from making use of this data in novel interfaces and research projects. We present the CarDaT (Car Data Toolkit) that uses Android smartphones to provide multidimensional sensor data in a minimal invasive way. CarDaT combines smartphone sensor data with data sources like OBD-II as well as other easily available remote data (e.g., weather). This data and the provided connectivity enable researchers to gather data on human behavior and designers to create novel context-aware interface solutions. Thus, CarDaT offers a low-cost, manufacturer independent and scalable in-car agile prototyping and research environment. In this paper we describe how we used smartphones in the CarDaT as tools for automotive research and design. We demonstrate potentials of CarDaT by describing three applications that we developed with the toolkit, namely rear seat games, an experience sampling study, as well as an experiment using car data in a driver distraction study to inform design.

The steering wheel is a promising space for the integration of displays since in the car there is very limited space for integrating interactive modalities for the driver that are close to the preferred field of view as well as in an easy to reach position. When the wheel is turned, the screen content could change its orientation to increase the readability and therefore reduce the distraction from the road. Thus, this paper describes three different content rotation behaviors for steering wheel displays. To investigate what effect these behaviors have on the driver in terms of visual distraction from the road we conducted a user study with eye tracking asking participants to read the current speed. We found no differences in terms of distraction and response time between the different rotation behaviors. Compared to a similar display in a dashboard position the visual distraction was reduced.

There is today a large number of ADAS used while driving. These systems are mainly technology driven and most often fail to make use of the social nature and the collaborative mechanisms between driver-passenger pairs. To inform the development of future automotive user interface designs we need to develop a deeper understanding of collaboration in general. In addition, we need to develop an understanding of how, and in what way, other platforms (e.g., the mobile phones) are and will be used in combination with these systems while driving. This paper presents the results of a participative ethnographic study with nine driver-passenger pairs recruited from two online car-sharing portals. Results are categorized in three areas: common ground as a base for successful in-car communication, types and strategies of front-seat passenger assistance, and lastly the impact of technology on collaboration.

This paper addresses the field of mobile payment through Near Field Communication (NFC) and Automated Teller Machines (ATMs). We report how we used the Inspirational Bits method to inspire the design of novel NFC usage scenarios and application ideas for ATMs in a joint industry and academia project. We describe a set of small applications exposing different properties of NFC (henceforth, referred to as NFC-Bits) and how they informed and inspired collaborative design ideas for different use cases. The NFC-Bits reveal a broad range of NFC characteristics in a playful manner. We outline some of the developed use cases and describe features of MyPocketATM, an application stemmed from these ideas.

This workshop addresses two strong fields within the Mobile HCI community: games & entertainment and transportation user interfaces. Using transportation technology (e.g., a car, plane, or traveling in public transportation) can be frustrating due to crowded streets, delays, and other travelers. Frustration may lead to aggression and negative experiences of other road members and passengers [4] leading to irrational behaviors [6]. Games & entertainment technology offer potential to resolve these negative user experiences. This workshop brings together entertainment and transportation user interface experts, who are willing to understand mobile entertainment technology as a potential solution to improve the experience of all travelers, drivers, and workers within the transportation field. The overall aim of the workshop is to create a common understanding of the challenges of entertainment in transportation, as well as further extend the research agenda for entertainment in this context from both from a scientific and an industrial perspective.

This paper introduces Trip Experience Sampling (TES)---a low-tech method to gather driver experiences in the car. It builds upon the original paper-and-pencil based experience sampling method and applies it to the automotive context. TES uses driver logbooks to survey user experience at the end of a trip while still sitting in the car. To proof the feasibility of TES we collected 475 trip experience samples from 20 participants in a field study. Our study showed that TES is a feasible and successful method to conduct user experience research in the car without distracting the driver. TES is a successful method in terms of return rate, trip diversity, data quality and subjective participants' responses. The strengths of the method lie in the entire abandonment of technology making it a quantifiable field method, which is easy to conduct.

Safe interaction with interactive systems in the car requires both hands to be placed on the steering wheel and eyes to be kept on the road. To allow safe text input in the vehicle, we propose the back of the steering wheel as space for interactive text input elements. In the effort to explore this space, we present two design alternatives for text input elements; one has two sliding sensors and the other has three buttons on each side of the wheel. In combination with a head up display and an adapted keyboard layout, these elements allow text input while driving with the eyes on the road an the hands on the wheel. In a first study with end users, we show the potential of the proposed text input approach for future vehicles.

Today, there is a trend towards integration of mobile (nomadic) devices into the car ecosystem. Thereby, this integration goes beyond using the devices' core features (such as making phone calls, short messaging, or using social media networks) in the car. Soon, tablets and smartphones will be a vital part of the car enabling services that cannot be used in the car without these devices anymore. This development leads to several research questions regarding the software engineering domain. In this workshop, we are going to discuss current challenges and promising approaches for integrating mobile devices into the car environment from different standpoints. Challenges regarding requirements engineering, user experience and software architecture will be addressed from different stakeholder viewpoints (User, OEM, supplier, 3rd party developer).

In terms of human computer interaction (HCI), the car interior is a space, which can be divided into three areas: the driver's area, the front seat area, and the back seat area. So far HCI researchers have primary focused on the driver, and how in-car electronic devices can be designed to assist the driver in order to increase safety and comfort. We propose that for investigating interactive technology in the car in a holistic way, all three areas have to be taken into account. For that purpose we argue for an increased usage of qualitative in-situ studies, which have been hardly applied in automotive user interface research. So far the HCI community has mainly focused on laboratory studies utilizing driving simulators. Despite the broad range of available field study methods, such as ethnographic and self-reporting studies, the adaption of these methods for the automotive context is challenging due to the specific characteristics of this environment. For instance, cars provide only very limited space, the environment is constantly changing while driving and the driver must not be distracted from driving safely. As a consequence, a lack of experience exists, on how in-situ methods should be applied to cars. In this paper we describe three qualitative in-situ studies, we conducted to research the driver, the front seat passenger, and the rear seat passenger spaces. All three studies used a different method tailored to fit these three areas best. To share our experiences and insights we discuss the strengths and pitfalls of each method.

This workshop is a forum of multi-disciplinary discussion on how mobile devices can increase perceived work efficiency (PWE), as well as how this subjective enhancement can be measured. It brings together practitioners and researchers from different domains interested in researching perceived workflow efficiency in the mobile context. The overall aim is to create a common base, as well as further extend the research agenda for work efficiency enhancement with the assistance of mobile devices both from a scientific, as well as from an industrial perspective.

In order to design in-car interfaces in a user-centered way it is necessary to understand users' experiences (UX). Therefore it is beneficial to gain early insight on the user acceptance (UA) of the system under development as a part of a holistic understanding of UX in the car. This paper describes a pre-study on the influence of drivers' characteristics (such as gender, self-concept, opinion) on the UA of eco-friendly in-car interfaces. Five interfaces that support environmental friendly driving were presented in an online questionnaire. No influences of socio-demographic variables and the self-concept components of the driver were found on UA. In opposition to that it is shown that users' wish for technology support and the general attitude towards technology have an influence on UA.

Measuring user acceptance to avoid system rejection by the users in pre-prototype stage of product development is of high interest for both researchers and practitioners. This is especially true when technology uses strategies of persuasion in an emotional laden environment like the car. This paper presents the results of an online survey aiming at evaluating the acceptance of future persuasive in-car interaction approaches for a more economic driving behaviour. Five different persuasive interface concepts are presented and studied towards their acceptance. The results show an overall acceptance of the system concepts and the usefulness of the presented method. We show that individual expectations of the systems' disturbance and risk have an effect on the acceptance of technology and the behavioural intention to use.

In my thesis I address the topic of mobile attachment. I provide a theoretical framework for mobile attachment together with influencing factors that indicate user's emotional attachment (EA) to mobile devices and services. I investigate how the concept of user experience (UX) and EA are linked together and I outline how user behavior driven experience sampling can be exploited to measure mobile attachment. My research will result in design suggestions how the creation of EA to mobile devices and services can be facilitated.

In this paper, we present an interactive mannequin for persuading bypassing customers to extend the perceived time they stay in front of a shop window. The mannequin was designed and prototyped to be seamlessly integrated into a shop window, constituting an ambient persuasion interface. The design concept of our virtual mannequin is based on actual real world mannequins. Based on implicit input from the customers, the mannequin reacts on their presence by looking into their direction. We implemented a prototype of the persuasive interactive mannequin (PIM) as a 3D model, visualized on a large LCD screen and deployed it in a retail store within a shopping mall. The results from a three days field study of this deployment are presented and discussed. The study results give insights about the persuasive effect of the mannequin as well as implications for the user centered design of interactive agents in the context of shopping.

This article investigates the prototypical implementation of a dynamic map of a retail store and the results of an empirical study in the shopping environment. Due to the distinct characteristics of the context of shopping (e.g. openness to the public, preexisting technologies), this context is particularly fruitful for UbiComp technologies. The prototype consists of a display showing an enhanced store map, which combines the dynamic visualization of customer activity (e.g. hot-spots, sales ranks) with conventional map elements (e.g. product locations, promotions). The results of our three-day in-situ study indicate the relevance and the usefulness of UbiComp technologies for shopping environments.