In virtual reality (VR) experiences, mismatches between reality and virtuality are usually undesirable, as they can disrupt immersion and induce cybersickness. However, when carefully controlled, they may expand the design space of VR. This research investigates perceptual detection thresholds for mismatches between real and virtual inclinations during cycling in VR. Using a custom simulation, N = 30 participants cycled through a virtual city while physical and visual inclinations were independently manipulated. Real inclinations were implemented with a tilting indoor bike, providing vestibular and proprioceptive feedback, while virtual inclinations within the simulated environment were presented visually. A multiple staircase procedure derived estimates for perceptual thresholds that approximate which mismatches in visual and physical inclination were still perceived as congruent. These thresholds reveal a window of perceived congruence before mismatches become noticeable to users. These findings advance understanding of sensory integration in VR cycling and inform applications in immersive training, exergames, and rehabilitation systems.

Automated vehicles (AVs) reached technological maturity and will soon arrive on streets as traffic participants.Human traffic participants such as drivers, pedestrians, or cyclists will be increasingly confronted with the presence of AVs within their environment, not necessarily knowing or understanding what to expect and how to interact with them.Although AVs are designed to act safely, effective interaction in mixed traffic scenarios will depend on successful communication, interaction, or even negotiation beyond static rules and regulations.Prosocial behavior, such as yielding one's right of way, will be needed to resolve unclear traffic situations or foster traffic flow.However, what are the characteristics of such prosocial behavior, and how to measure this not only for automated vehicles

Cultural differences influence how cyclists and drivers interact, affecting global autonomous vehicle (AV) adoption. AV-cyclist interfaces are needed to clarify AV intentions and resolve ambiguities when no human driver is present. These must adapt across cultures and road infrastructure. We conducted the first cross-cultural AV-cyclist user study across Stockholm (high segregation of cyclists from drivers), Glasgow (some segregation), and Muscat (no segregation). Cyclists used an AR simulator to cycle in physical space and experienced three holistic AV-cyclist interfaces. These integrated multiple interfaces into a larger ecosystem, e.g., a smartwatch synchronised with on-vehicle eHMI. Interfaces communicated AV location, intentions, or both. Riders from all cities preferred combined AV location and intention information but used it differently. Stockholm cyclists focused on location, validating intentions with driving behaviour. Glasgow riders valued both cues equally. Muscat cyclists trusted interfaces, prioritising intentions without relying on driving behaviour. These insights are key for global AV adoption.

Despite their ubiquity, bicycles remain largely unexplored as a space for personalization and cyclist-aware solutions. Since cycling is inherently a behavioral activity, we investigate its potential as a biometric trait for continuous identification and personalization. For this, we mounted multiple sensors on a regular bicycle and conducted an outdoor experiment (N = 16) across two sessions on two cycling tracks: a short, controlled track and a long, in-the-wild setup. This design enabled us to examine how stable cycling patterns are across sessions and how well individuals can be distinguished in controlled versus real-world conditions. Our findings demonstrate the feasibility of leveraging cycling behavior for continuous identification and personalization, achieving identification accuracies of up to 94.3%. We discuss the implications of these results for real-world deployment, as well as the challenges posed by environmental factors, rider variability, and the need for robust and unobtrusive sensing solutions.

Figure 1: The effects of audio and visual stimuli, and their interaction, on bitterness perception (left) and sweetness perception (right).Significant effects found for bitter taste are outlined in blue.

Figure 1: A participant is using the (a) museum app to listen to information about the artowrk and (b) chatbot that facilitates taking a picture of an artwork, retrieving auditory and textual information about the work, and an interactive chat to learn more about it.

Mixed-reality (MR) platforms are moving toward controller-free input, relying on hand gestures and eye tracking. In this paper, we explore on-body micro-gestures as alternatives to MR gameplay via two implemented techniques – Palm and Knuckle – modeled on joystick steering and button tapping. We evaluated them with 24 participants, who played a third-person MR adventure game using the proposed techniques and a gaming controller. We found that the controller leads to the fastest and most precise performance. While Palm produced the most attacks and enemy kills and imposed the highest workload, Knuckle was rated the most enjoyable and socially acceptable in public. We demonstrate that although physical controllers are superior in speed and accuracy, on-body micro-gestures emerge as an appealing alternative/complement for casual or mobile MR play.

Virtual Reality (VR) locomotion methods are mainly ground-based, room-scale, or discrete, making them ill-suited for flying experiences. Although leaning- and controller-based techniques are promising for flying in VR, we lack empirical evidence of their advantages. We compared combinations of leaning- and controller-based methods for steering and velocity in a user study (N = 24) using a broom metaphor to integrate these methods into an understandable locomotion reference. The steering methods were: 1) controller-pointing (CP) and 2) headset-leaning (HL); and for velocity control: 1) controller linear displacement (CLD) and 2) headset linear displacement (HLD). Results indicate that HL increase presence compared to CP. However, combining HL with CLD worsens coin collection rate, completion time, mental load, control factor ratings, and enjoyment. In contrast, HLD worked well when paired with either steering method. CP-CLD led to the highest coin collection rate and lowest mental load. All methods had comparable feelings of flying.

Interaction techniques for room-scale Virtual Reality (VR) are commonly presented wholesale; however, decoupling the mechanics and signifiers of these interactions offers new interaction possibilities. To explore the effect of signifiers on VR interactions, we created two new interaction techniques (forward-axis compression and multi-axis compression) with identical mechanical mappings to the existing Go-Go technique but with different signifiers. We conducted usability and illusory detection studies (N=18) to compare the interactions. Our results indicate that participants had comparable performance regarding target selection time and the number of missclicks with standard Go-Go and forward-axis compression for both small and large spheres. Additionally, multi-axis compression causes Go-Go to become illusory at low-distance multipliers. We propose that separating mechanics from signifiers is beneficial for creating new VR interactions.

Brain-robot interaction (BRI) empowers individuals to control (semi-)automated machines through brain activity, either passively or actively. In the past decade, BRI systems have advanced significantly, primarily leveraging electroencephalogram (EEG) signals. This article presents an up-to-date review of 87 curated studies published between 2018 and 2023, identifying the research landscape of EEG-based BRI systems. The review consolidates methodologies, interaction modes, application contexts, system evaluation, existing challenges, and future directions in this domain. Based on our analysis, we propose a BRI system model comprising three entities: Brain, Robot, and Interaction, depicting their internal relationships. We especially examine interaction modes between human brains and robots, an aspect not yet fully explored. Within this model, we scrutinize and classify current research, extract insights, highlight challenges, and offer recommendations for future studies. Our findings provide a structured design space for human-robot interaction (HRI), informing the development of more efficient BRI frameworks.

Cycling Human-Computer Interaction (CyclingHCI) refers to the study and design of user interfaces and interactions between bicycles and riders in the context of cycling-related experiences. To date, however, there has yet to be a structured agenda for CyclingHCI to clarify the immediate challenges researchers should address next and facilitate the advancement of the field. We, three CyclingHCI researchers who collectively designed, developed, evaluated 18 CyclingHCI projects, reflected on our experiences to derive 10 grand challenges that we articulate with design opportunities and considerations grouped into: (1) Pushing the technological boundaries for cycling, (2) Understanding and protecting cyclists, and (3) Spatially situated cycling interaction. Our findings provide practical implications for research and practice in CyclingHCI, with which we aim to enrich the cycling experience through the safe integration of technology.

Creating Mixed Reality applications poses distinct challenges for development and design. One of the challenges is designing Mixed Reality application-specific experiences in the wild. In this paper, we present a structured reflection approach to revisit projects from the past. In applying this structured reflection to the data collected during a nine-month industrial project, we unveiled the Virtuality-Reality Clash. To generate a sufficient data corpus, we structurally analysed git commits, tickets, emails, handwritten notes, and weekly snapshots of the 3D designs. The clash could be narrowed down in our data corpus to the situations in which we were fusing the real environment with the virtual content. Finally, we could find five design patterns for MR experience. With these patterns, we aim to help developers and designers of MR applications identify situations where Virtuality and Reality clash and propose approaches to address them.

The field of Sports Human-Computer Interaction (SportsHCI) investigates interaction design to support a physically active human being. Despite growing interest and dissemination of SportsHCI literature over the past years, many publications still focus on solving specific problems in a given sport. We believe in the benefit of generating fundamental knowledge for SportsHCI more broadly to advance the field as a whole. To achieve this, we aim to identify the grand challenges in SportsHCI, which can help researchers and practitioners in developing a future research agenda. Hence, this paper presents a set of grand challenges identified in a five-day workshop with 22 experts who have previously researched, designed, and deployed SportsHCI systems. Addressing these challenges will drive transformative advancements in SportsHCI, fostering better athlete performance, athlete-coach relationships, spectator engagement, but also immersive experiences for recreational sports or exercise motivation, and ultimately, improve human well-being.

Rowing has great potential in Virtual Reality (VR) exergames as it requires physical effort and uses physical motion to map the locomotion in a virtual space. However, rowing in VR is currently restricted to locomotion along one axis, leaving 2D and 3D locomotion out of the scope. To facilitate rowing-based locomotion, we implemented three steering techniques based on head, hands, and feet movements for 2D and 3D VR environments. To investigate these methods, we conducted a controlled experiment (N = 24) to assess the user performance, experience and VR sickness. We found that head steering leads to fast and precise steering in 2D and 3D, and hand steering is the most realistic. Feet steering had the largest performance difference between 2D and 3D but comparable precision to hands in 2D. Lastly, head steering is the least mentally demanding, and all methods had comparable VR sickness.

Politeness and embodiment are pivotal elements in human-agent interactions. While many previous works advocate the positive role of embodiment in enhancing these interactions, it remains unclear how embodiment and politeness affect individuals joining groups. In this paper, we explore how politeness behaviors (verbal and nonverbal) exhibited by three distinct embodiments (humans, robots, and virtual characters) influence individuals’ decisions to join a group of two agents in a controlled experiment (N=54). We assessed agent effectiveness regarding persuasiveness, perceived politeness, and participants’ trajectories when joining the group. We found that embodiment does not significantly impact agent persuasiveness and perceived politeness, but politeness does. Direct and explicit politeness strategies have a higher success rate in persuading participants to join the group at the furthest side. Lastly, participants adhered to social norms when joining at the furthest side, maintained a greater physical distance from humans, chose longer paths, and walked faster when interacting with humans.

Figure 1: The coniotomy procedure: (A) the larynx is covered with a few layers of tape, (B) the larynx is slided into the housing structure, (C) the larynx is covered by artificial skin that has to be clamped by the device, (D) the exact position of the vertical cut has to be determined and a cut has to be performed, (E) after the vertical cut, the ligaments have to be cut horizontally for a few centimetres to facilitate the insertion of the tube, (F) the tube can be inserted deep enough to ventilate the patient.

From carrying grocery bags to holding onto handles on the bus, there are a variety of situations where one or both hands are busy, hindering the vision of ubiquitous interaction with technology. Voice commands, as a popular hands-free alternative, struggle with ambient noise and privacy issues. As an alternative approach, research explored movements of various body parts (e.g., head, arms) as input modalities, with foot-based techniques proving particularly suitable for hands-free interaction. Whereas previous research only considered the movement of the foot as a whole, in this work, we argue that our toes offer further degrees of freedom that can be leveraged for interaction. To explore the viability of toe-based interaction, we contribute the results of a controlled experiment with 18 participants assessing the impact of five factors on the accuracy, efficiency and user experience of such interfaces. Based on the findings, we provide design recommendations for future toe-based interfaces.

As the world becomes more interconnected, physical separation between people increases. Existing collaborative Virtual Reality (VR) applications, designed to bridge this distance, are not yet sufficient in providing a sense of social connection comparable to face-to-face interactions. Possible reasons are the limited multimodality of VR systems and the lack of non-verbal cues in VR avatars. We systematically investigated how facial expressions influence Social Presence in two collaborative VR tasks. We explored four types of facial expressions: eyes and mouth movements, their combination, and no expressions, for two types of explanations: verbal and graphical. To examine how these expressions influence Social Presence, we conducted a controlled VR experiment (N = 48), in which participants had to explain a specific term to their counterpart. Our results demonstrate that eye and mouth movements positively influence Social Presence in VR. Particularly, combining verbal explanations and eye movements induces the highest feeling of co-presence.

Creating highly realistic Virtual Reality (VR) bicycle experiences can be time-consuming and expensive. Moreover, it is unclear what hardware parts are necessary to design a bicycle simulator and whether a bicycle is needed at all. In this paper, we investigated cycling fidelity and control of VR bicycle simulators. For this, we developed and evaluated three cycling simulators: (1) cycling without a bicycle (bikeless), (2) cycling on a fixed (stationary) and (3) moving bicycle (tandem) with four levels of control (no control, steering, pedaling, and steering + pedaling). To evaluate all combinations of fidelity and control, we conducted a controlled experiment (N = 24) in indoor and outdoor settings. We found that the bikeless setup provides the highest feeling of safety, while the tandem leads to the highest realism without increasing motion sickness. Moreover, we discovered that bicycles are not essential for cycling in VR.

The annotation of 3D point cloud datasets is an expensive and tedious task. To optimize the annotation process, recent works have proposed the use of environments with higher levels of immersion in combination with different types of visual aids. However, two problems remain unresolved. First, the proposed environments limit the user to a unique level of immersion and a fixed hardware setup. Second, their design overlooks the interaction effects between the level of immersion and the visual aids on the quality of the annotation process. To address these issues, we propose PointCloudLab, an environment for 3D point cloud annotation that allows the use of different levels of immersion that work in combination with visual aids. Using PointCloudLab, we conducted a controlled experiment (N=20) to investigate the effects of levels of immersion and visual aids on the annotation process. Our findings reveal that higher levels of immersion combined with object-based visual aids lead to a faster and more accurate annotation. Furthermore, we found significant interaction effects between the levels of immersion and the visual aids on the accuracy of the annotation.

As programming is typically a static activity in front of a screen, we perform an initial exploration around the capabilities of block-based programming in the immersive space using Virtual Reality (VR) to make an early charting on how programming could involve moving the programmer’s body. We created a block-based programming interface in a VR space called BlocklyVR based on the existing Blockly programming environment. To investigate programmer performance and experience in BlocklyVR, we conducted a controlled lab experiment (N = 20) with eight programming tasks that covered mathematical operations, if-statements, and function creation. Our initial exploration contributes by classifying movement types made by BlocklyVR programmers and reflecting on how these movements are related to the programming tasks. Additionally, our data suggests that participant performance in BlocklyVR was not affected compared to the 2D Blockly, even if participants were physically moving in VR space. We also found that the virtual reality sickness was marginal. Lastly, we identified four types of interaction that can potentially be employed by VR designers and developers aiming to convert a static task, like programming at a desk, into a “mobile” immersive experience.

Walk-in-Place is an established locomotion technique for walking in virtual environments, as it incorporates body motion similar to regular walking. Although there is extensive research on the performance and experience of walking in virtual reality spaces, it typically requires minimal-to-moderate physical movement, e.g., stepping forward and turning around, to explore virtual spaces. Therefore, the question we ask ourselves in this work is how user experience and performance are affected when the user is actively moving in place. In this paper, we explored three body-steering methods for jogging-in-place in virtual environments: (1) head-, (2) hand-, and (3) torso-based. To investigate the performance of the proposed body-steering methods for jogging in virtual reality, we conducted a controlled lab experiment (N = 12) to assess task completion time, number of steps, and VR sickness. We discovered that hand- and torso-based methods require fewer steps than the head-based method, and the torso-based is slower than the other two. Moreover, the number of collisions and virtual reality sickness were comparable among the methods.

Research on cyclists‘ safety and comfort is a growing topic. Existing works address support systems with novel interaction concepts such as augmented reality but also the design and evaluation of high-fidelity bicycle simulators. Since the field is still in its exploratory phase, there have been few attempts to systematically provide guidance for conducting experiments. For example, there is no consensus on the choice of representative driving scenarios, the proper choice of different bicycle simulators, and measurement standards to systematically compare the results of different studies. With this workshop, we want the community to gather and discuss a roadmap for the future of HCI bicycle research so that these issues can be overcome.

Most digital bodily games focus on the body as they use movement as input. However, they also draw the player’s focus away from the body as the output occurs on visual displays, creating a divide between the physical body and the virtual world. We propose a novel approach – the "Body as a Play Material" – where a player uses their body as both input and output to unify the physical body and the virtual world. To showcase this approach, we designed three games where a player uses one of their hands (input) to play against the other hand (output) by loaning control over its movements to an Electrical Muscle Stimulation (EMS) system. We conducted a thematic analysis on the data obtained from a field study with 12 participants to articulate four player experience themes. We discuss our results about how participants appreciated the engagement with the variety of bodily movements for play and the ambiguity of using their body as a play material. Ultimately, our work aims to unify the physical body and the virtual world.

Haptic Feedback is essential for lifelike Virtual Reality (VR) experiences. To provide a wide range of matching sensations of being touched or stroked, current approaches typically need large numbers of different physical textures. However, even advanced devices can only accommodate a limited number of textures to remain wearable. Therefore, a better understanding is necessary of how expectations elicited by different visualizations affect haptic perception, to achieve a balance between physical constraints and great variety of matching physical textures.

Teleportation has become the de facto standard of locomotion in Virtual Reality (VR) environments. However, teleportation with parabolic and linear target aiming methods is restricted to horizontal 2D planes and it is unknown how they transfer to the 3D space. In this paper, we propose six 3D teleportation methods in virtual environments based on the combination of two existing aiming methods (linear and parabolic) and three types of transitioning to a target (instant, interpolated and continuous). To investigate the performance of the proposed teleportation methods, we conducted a controlled lab experiment (N = 24) with a mid-air coin collection task to assess accuracy, efficiency and VR sickness. We discovered that the linear aiming method leads to faster and more accurate target selection. Moreover, a combination of linear aiming and instant transitioning leads to the highest efficiency and accuracy without increasing VR sickness.

Cycling has become increasingly popular as a means of transportation. However, cyclists remain a highly vulnerable group of road users. According to accident reports, one of the most dangerous situations for cyclists are uncontrolled intersections, where cars approach from both directions. To address this issue and assist cyclists in crossing decision-making at uncontrolled intersections, we designed two visualizations that: (1) highlight occluded cars through an X-ray vision and (2) depict the remaining time the intersection is safe to cross via a Countdown. To investigate the efficiency of these visualizations, we proposed an Augmented Reality simulation as a novel evaluation method, in which the above visualizations are represented as AR, and conducted a controlled experiment with 24 participants indoors. We found that the X-ray ensures a fast selection of shorter gaps between cars, while the Countdown facilitates a feeling of safety and provides a better intersection overview.

Virtual Reality (VR) bicycle simulations aim to recreate the feeling of riding a bicycle and are commonly used in many application areas. However, current solutions still create mismatches between the visuals and physical movement, which causes VR sickness and diminishes the cycling experience. To reduce VR sickness in bicycle simulators, we conducted two controlled lab experiments addressing two main causes of VR sickness: (1) steering methods and (2) cycling trajectory. In the first experiment (N = 18) we compared handlebar, HMD, and upper-body steering methods. In the second experiment (N = 24) we explored three types of movement in VR (1D, 2D, and 3D trajectories) and three countermeasures (airflow, vibration, and dynamic Field-of-View) to reduce VR sickness. We found that handlebar steering leads to the lowest VR sickness without decreasing cycling performance and airflow suggests to be the most promising method to reduce VR sickness for all three types of trajectories.

Cyclists' attention is often compromised when interacting with notifications in traffic, hence increasing the likelihood of road accidents. To address this issue, we evaluate three notification interaction modalities and investigate their impact on the interaction performance while cycling: gaze-based Dwell Time, Gestures, and Manual And Gaze Input Cascaded (MAGIC) Pointing. In a user study (N=18), participants confirmed notifications in Augmented Reality (AR) using the three interaction modalities in a simulated biking scenario. We assessed the efficiency regarding reaction times, error rates, and perceived task load. Our results show significantly faster response times for MAGIC Pointing compared to Dwell Time and Gestures, while Dwell Time led to a significantly lower error rate compared to Gestures. Participants favored the MAGIC Pointing approach, supporting cyclists in AR selection tasks. Our research sets the boundaries for more comfortable and easier interaction with notifications and discusses implications for target selections in AR while cycling.

Augmented Reality (AR) has influenced the presentation of historical information to tourists and museum visitors by making the information more immersive and engaging. Since smartphones and AR glasses are the primary devices to present AR information to users, it is essential to understand how the information about a historical site can be presented effectively and what type of device is best suited for information placements. In this paper, we investigate the placement of two types of content, historical images and informational text, for smartphones and AR glasses in the context of outdoor historical sites. For this, we explore three types of placements: (1) on-body, (2) world, and (3) overlay. To evaluate all nine combinations of text and image placements for smartphone and AR glasses, we conducted a controlled experiment (N = 18) at outdoor historical landmarks. We discovered that on-body image and text placements were the most convenient compared to overlay and world for both devices. Furthermore, participants found themselves more successful in exploring historical sites using a smartphone than AR glasses. Although interaction with a smartphone was more convenient, participants found exploring AR content using AR glasses more fun.

We envision a future where self-driving bicycles can take us to our destinations. This allows cyclists to use their time on the bike efficiently for work or relaxation without having to focus their attention on traffic. In the related field of self-driving cars, research has shown that communicating the planned route to passengers plays an important role in building trust in automation and situational awareness. For self-driving bicycles, this information transfer will be even more important, as riders will need to actively compensate for the movement of a self-driving bicycle to maintain balance. In this paper, we investigate maneuver indications for self-driving bicycles: (1) ambient light in a helmet, (2) head-up display indications, (3) speech feedback, (4) vibration on the handlebar, and (5) no assistance. To evaluate these indications, we conducted an outdoor experiment (N = 25) in a proposed tandem simulator consisting of a tandem bicycle with a steering and braking control on the back seat and a rider in full control of it. Our results indicate that riders respond faster to visual cues and focus comparably on the reading task while riding with and without maneuver indications. Additionally, we found that the tandem simulator is realistic, safe, and creates an awareness of a human cyclist controlling the tandem.

Bicycle simulators are becoming an increasingly used research tool. However, due to the complex cycling dynamics, these simulators have issues of simulator sickness and perceived realism. A potential method to address these issues could be providing a motion-based tilting function. Some bicycle simulators with tilt functionality have already been presented but still lack a systematic evaluation. In this work, we present a motion-based bicycle simulator without centrifugal force simulation and the results from a user study that compared different tilt modes. N=31 participants completed a study in virtual reality with a strong and a weak tilt mode, as well as a baseline condition without movement. We discovered that weak tilting could significantly improve the cycling realism without decreasing cycling performance and simulator sickness. Furthermore, our research suggests that there is a sweet spot for a tilting function, which facilitates a balance between presence/immersion and simulator sickness.

Two-factor authentication (2FA) is a recommended or imposed authentication mechanism for valuable online assets. However, 2FA mechanisms usually exhibit user experience issues that create user friction and even lead to poor acceptance, hampering the wider spread of 2FA. In this article, we investigate user perceptions of 2FA through in-depth interviews with 42 participants, revealing key requirements that are not well met today despite recently emerged 2FA solutions. First, we investigate past experiences with authentication mechanisms emphasizing problems and aspects that hamper good user experience. Second, we investigate the different authentication factors more closely. Our results reveal particularly interesting preferences regarding the authentication factor “ownership” in terms of properties, physical realizations, and interaction. These findings suggest a path toward 2FA mechanisms with considerably better user experience, promising to improve the acceptance and hence, the proliferation of 2FA for the benefit of security in the digital world.

Learning a musical instrument requires regular exercise. However, students are often on their own during their practice sessions due to the limited time with their teachers, which increases the likelihood of mislearning playing techniques. To address this issue, we present Let’s Frets - a modular guitar learning system that provides visual indicators and capturing of finger positions on a 3D-printed capacitive guitar fretboard. We based the design of Let’s Frets on requirements collected through in-depth interviews with professional guitarists and teachers. In a user study (N=24), we evaluated the feedback modules of Let’s Frets against fretboard charts. Our results show that visual indicators require the least time to realize new finger positions while a combination of visual indicators and position capturing yielded the highest playing accuracy. We conclude how Let’s Frets enables independent practice sessions that can be translated to other musical instruments.

Accurate sketching in virtual 3D environments is challenging due to aspects like limited depth perception or the absence of physical support. To address this issue, we propose VRSketchPen – a pen that uses two haptic modalities to support virtual sketching without constraining user actions: (1) pneumatic force feedback to simulate the contact pressure of the pen against virtual surfaces and (2) vibrotactile feedback to mimic textures while moving the pen over virtual surfaces. To evaluate VRSketchPen, we conducted a lab experiment with 20 participants to compare (1) pneumatic, (2) vibrotactile and (3) a combination of both with (4) snapping and no assistance for flat and curved surfaces in a 3D virtual environment. Our findings show that usage of pneumatic, vibrotactile and their combination significantly improves 2D shape accuracy and leads to diminished depth errors for flat and curved surfaces. Qualitative results indicate that users find the addition of unconstraining haptic feedback to significantly improve convenience, confidence and user experience.

Navigation systems for cyclists are commonly screen-based devices mounted on the handlebar which show map information. Typically, adult cyclists have to explicitly look down for directions. This can be distracting and challenging for children, given their developmental differences in motor and perceptual-motor abilities compared with adults. To address this issue, we designed different unimodal cues and explored their suitability for child cyclists through two experiments. In the first experiment, we developed an indoor bicycle simulator and compared auditory, light, and vibrotactile navigation cues. In the second experiment, we investigated these navigation cues in-situ in an outdoor practice test track using a mid-size tricycle. To simulate road distractions, children were given an additional auditory task in both experiments. We found that auditory navigational cues were the most understandable and the least prone to navigation errors. However, light and vibrotactile cues might be useful for educating younger child cyclists.

Child cyclists are at greater risk for car-to-cyclist accidents than adults. This is in part due to developmental differences in the motor and perceptual-motor abilities of children and adults, and missing cycling infrastructure. To address these issues, we examine unimodal and projection-based techniques to support children in maintaining a good lane position in the absence of bicycle lanes. We present safety-relevant information using unimodal cues: vibration on the handlebar, ambient light in a cycle helmet, projected heads-up display indicators, and on-road laser projection. As a first step, we interviewed twelve children about their cycling issues. We then conducted a lab experiment (N=25) in a bicycle simulator using the unimodal cues in the presence of a visual search task, followed by a controlled test-track experiment (N=15). We found that cycling performance with lane keeping cues was comparable to situations without them, however children found them helpful and expressed subjective preferences for the LED helmet and vibration on the handlebar.

Grandparents and grandchildren that live apart often rely on communication technologies, such as messengers, video conferencing, and phone calls for maintaining relationships. While some of these systems are challenging for grandparents, others are less engaging for children. To facilitate communication, we developed StoryBox, a tangible device that allows sharing photos, tangible artifacts, and audio recordings of everyday life. We conducted a preliminary study with two families to identify design issues, and further refine the prototype. Subsequently, we conducted a field study with four families for up to four weeks to better understand real-world use and examine inter-generational connectedness. We found that StoryBox was accessible, simple, and helped bridge the technological gap between grandparents and grandchildren. Children communicated asynchronously in a playful and idiosyncratic manner, and grandparents shared past family memories. We provide insights on how to ease communication between different generations, engage them in sharing activities, and strengthen family relationships.

Child cyclists are often at greater risk for traffic accidents. This is in part due to the development of children's motor and perceptual-motor abilities. To facilitate road safety for children, we explore the use of multimodal warning signals to increase their awareness and prime action in critical situations. We developed a bicycle simulator instrumented with these signals and conducted two controlled experiments. We found that participants spent significantly more time perceiving visual than auditory or vibrotactile cues. Unimodal signals were the easiest to recognize and suitable for encoding directional cues. However, when priming stop actions, reaction time was shorter when all three modalities were used simultaneously. We discuss the implications of these outcomes with regard to design of safety systems for children and their perceptual-motor learning.

Car navigation systems typically combine multiple output modalities; for example, GPS-based navigation aids show a real-time map, or feature spoken prompts indicating upcoming maneuvers. However, the drawback of graphical navigation displays is that drivers have to explicitly glance at them, which can distract from a situation on the road. To decrease driver distraction while driving with a navigation system, we explore the use of ambient light as a navigation aid in the car, in order to shift navigation aids to the periphery of human attention. We investigated this by conducting studies in a driving simulator, where we found that drivers spent significantly less time glancing at the ambient light navigation aid than on a GUI navigation display. Moreover, ambient light-based navigation was perceived to be easy to use and understand, and preferred over traditional GUI navigation displays. We discuss the implications of these outcomes on automotive personal navigation devices.

Recent interest in the development of ambient light systems has initialized a new research area, where the number of ambient light systems is expected to increase in the next years. To support the development of future ambient light systems, we need clear, explicit, and structured design guidelines. In this paper we present an evaluation of light patterns in a controlled laboratory study with two complementary parts. In the first part, our aim was to reveal and analyze light patterns that encode different types of everyday information. In the second part, we verified the results from the first part by asking another group of participants about their understanding of information encoded with light. Together, our results allowed us to establish light patterns and guidelines for building new ambient light systems and applications in the future.