Traditional software development workflows, which rely primarily on physical multi-monitor setups, are effective for developing desktop and server-based applications that display output to users via monitors. However, these workflows face limitations in domains such as cyber-physical systems, particularly in robotics, where applications must interact directly with the physical environment. In such domains, digital twins offer an opportunity to visualize and debug these systems within a simulated and realistic environment.

This literature review examines the use of virtual reality in ergonomic risk assessment in workplace design using a rigorous methodology to evaluate literature from seven databases and journals. The review identified 4,377 records, of which nineteen used virtual reality to simulate complex work environments, such as manufacturing floors and office spaces, utilizing motion tracking and risk assessment methods, including the Ergonomic Assessment Worksheet (EAWS) or CUELA (German acronym for Computer-aided recording and long-term analysis of musculoskeletal system loads). The research suggests that integrating virtual reality with established ergonomic assessment methods holds promise for enhancing their efficacy. However, it also highlights the limitations of current virtual reality simulation tools in implementing realistic interactions with the working environment. The importance of this review lies in its capacity to synthesize and structure a previously fragmented field, providing researchers and practitioners with a comprehensive overview of current approaches, challenges, and opportunities in VR-based ergonomic risk assessment. It concludes that virtual reality has high potential but requires further research to fully realize its benefits in designing ergonomic workplaces, conducting thorough ergonomic evaluations, and being integrated into occupational health and safety on a large scale.

Interface metaphors are thought to enable an intuitive and effective interaction with a user interface by allowing users to draw on existing knowledge and reducing the need for instructions. This makes metaphors a promising candidate to drive the development of locomotion interfaces for virtual reality (VR). Since creating metaphoric interfaces can be difficult, it is important to analyze how typical locomotion metaphors can support an intuitive interaction. We performed a qualitative online study to observe the effect of typical metaphors (Walking, Steering, Flying, and Teleportation) and the influence of perceived affordances and user background. Our analysis shows that users adapt the interface expectations induced by metaphors to fit the perceived affordances instead of changing them. Several interests, the age, education, and gender influenced the expectations regarding the VR locomotion interface. Our findings contribute to a better understanding of users' mental models of VR locomotion metaphors, which seem necessary for designing more intuitive locomotion.

Ergonomic Workplace Assessment aims to assess potential risks and measure the ergonomic characteristics of various workplaces. Virtual reality might offer great benefits as it enables cost-effective workplace evaluations in early planning phases. This study aims to investigate the validity of motion-capture-based ergonomic evaluations in virtual environments (VE) compared to real environments (RE), focusing on the role of passive haptics. In a 3\4 design, 22 subjects performed four work tasks in three environmental conditions: RE, VE, and VE with passive haptic feedback (PH). Whole-body motion data were recorded and analyzed using repeated measures ANOVA. Eighteen joint angle percentiles were analyzed across all tasks and environments. Significant differences in trunk and shoulder movements were found between RE and VE, especially during physically demanding tasks such as repetitive lifting. Passive haptics reduced differences in nine task-joint constellations but introduced new ones in seventeen others, particularly shoulder joints. Overall, the results highlight the context-specific effects of passive haptics: while it can improve motion realism in VE, it can also induce task-specific artifacts.

Augmented Virtuality integrates physical content into virtual environments, but the occlusion of physical by virtual content is a challenge. This unwanted occlusion may disrupt user interactions with physical devices and compromise safety and usability. This paper investigates two resolution strategies to address this issue: Redirected Walking, which subtly adjusts the user’s movement to maintain physical-virtual alignment, and Automatic Teleport Rotation, which realigns the virtual environment during travel. A user study set in a virtual forest demonstrates that both methods effectively reduce occlusion. While in our testbed, Automatic Teleport Rotation achieves higher occlusion resolution, it is suspected to increase cybersickness compared to the less intrusive Redirected Walking approach.

Home-based exercise programs are a cornerstone in managing chronic non-specific back pain. However, their effectiveness is often limited by low adherence and incorrect exercise execution. This study presents and evaluates a Mixed Reality (MR) biofeedback system that tracks body motion using a multi-Kinect setup and provides real-time feedback via the Microsoft HoloLens 2. The evaluation focuses on whether the proposed real-time biofeedback enables participants to perform physiotherapy exercises more accurately and in closer alignment with prescribed guidance in a home-based setting, while also assessing system usability as well as cognitive and emotional workload experienced by users.

Collaborative work in social virtual reality often requires an interplay of loosely coupled collaboration from different virtual locations and tightly coupled face-to-face collaboration. Without appropriate system mediation, however, transitioning between these phases requires high navigation and coordination efforts. In this paper, we present an interaction system that allows collaborators in virtual reality to seamlessly switch between different collaboration models known from related work. To this end, we present collaborators with functionalities that let them work on individual sub-tasks in different virtual locations, consult each other using asymmetric interaction patterns while keeping their current location, and temporarily or permanently join each other for face-to-face interaction. We evaluated our methods in a user study with 32 participants working in teams of two. Our quantitative results indicate that delegating the target selection process for a long-distance teleport significantly improves placement accuracy and decreases task load within the team. Our qualitative user feedback shows that our system can be applied to support flexible collaboration. In addition, the proposed interaction sequence received positive evaluations from teams with varying VR experiences.

Real-world robot system deployment is often performed in complex and unstructured environments. These complex environments coupled with multi-faceted global tasks often lead to complicated stakeholder structures, making designing for these environments extremely challenging. Magnifying this difficulty, tasks performed in these environments often cannot be accomplished by a single robot or even single robot type because of the broad range of needs and psychical constraints of the robots. In these cases, heterogeneous robot teams may need to be coupled to human team members to perform the global tasks. From a Human-Robot Interaction (HRI) perspective, this increases the complexity of designing and deploying the system significantly, as now complicated stakeholder structures are mixed with complex robot teams. This paper presents a novel real-world system and interface design leveraging multiple mediums to balance stakeholder needs. To this end, the UI presented here incorporates features that support shared mental models (SMMs), trust establishment and development, and utilizes a centralized data distribution architecture to improve team performance. In addition to the interface, this paper presents a detailed look at the design process and the lessons learned from the perspective of a multi-year, real-world deployed system, as part of a large European project consisting of 21 partners from varying countries and backgrounds.

The user study presented in this paper explores the effects that being immersed in different virtual scenes has on a user’s avatar-design behavior. For this purpose, we have developed a character creation tool that lets users configure their appearance in Virtual Reality. This tool has then been employed in a user study involving 33 participants, who were asked to configure a virtual avatar in a beach and a hospital environment. Our results show that the environment that participants were immersed in influenced their design behavior, with the beach environment leading to a more extensive use of accessories than the hospital scene. Against our expectations, most participants stated to have had little intention to represent either their real or ideal selves, instead opting to explore different characters that they found funny, likable, or interesting. In addition, we found indications for a possible connection between the participants’ feelings of presence and how they incorporate features of themselves into their avatar designs.

Virtual Reality presents a promising tool for knowledge transfer, allowing users to learn in different environments and with the help of three-dimensional visualizations. At the same time, having to learn new ways of interacting with their environment can present a significant hurdle for novice users. When users enter a virtual space to receive knowledge from a more experienced person, the question arises as to whether they benefit from learning VR-specific interaction techniques instead of letting the expert take over some or all interactions. Based on related work about expert-novice interaction in virtual spaces, this paper presents a user study comparing three different distributions of interaction responsibilities between participants and an expert user. The Role-Based interaction mode gives the expert the full interaction responsibility. The Shared interaction mode gives both users the same interaction capabilities, allowing them to share the responsibility of interacting with the virtual space. Finally, the Parallel interaction mode gives participants full interaction responsibility, while the expert can provide guidance through oral communication and visual demonstration. Our results indicate that assuming interaction responsibility led to higher task loads but also increased the participant’s engagement and feeling of presence. For most participants, sharing interaction responsibilities with the expert represented the best trade-off between engagement and challenge. While we did not measure a significant increase in learning success, participant comments indicated that they also paid more attention to details when assuming more interaction responsibility.

Immersive authoring enables content creation for virtual environments without a break of immersion. To enable immersive authoring of reactive behavior for a broad audience, we present modulation mapping, a simplified visual programming technique. To evaluate the applicability of our technique, we investigate the role of reference frames in which the programming elements are positioned, as this can affect the user experience. Thus, we developed two interface layouts: "surround-referenced" and "object-referenced". The former positions the programming elements relative to the physical tracking space, and the latter relative to the virtual scene objects. We compared the layouts in an empirical user study (n = 34) and found the surround-referenced layout faster, lower in task load, less cluttered, easier to learn and use, and preferred by users. Qualitative feedback, however, revealed the object-referenced layout as more intuitive, engaging, and valuable for visual debugging. Based on the results, we propose initial design implications for immersive authoring of reactive behavior by visual programming. Overall, modulation mapping was found to be an effective means for creating reactive behavior by the participants.

Back pain significantly impacts society, leading to substantial economic costs and reducing individuals’ quality of life. A digital XR physiotherapist could support adherence to home-based training programs, thereby potentially enhancing treatment effectiveness. For the system to provide accurate biofeedback, which is crucial to the success of the system, it must be capable of tracking exercise execution reliably and accurately.

Performance and user satisfaction are key quality indicators in immersive analytics. Performance in terms of, e.g., error rate can only be measured if a ground truth is known to evaluate whether a user action or analysis result is erroneous. Thus, an estimate measure is needed to indicate the user's performance without having a ground truth available. This work investigates flow, sense of agency and presence as possible candidates in two experiments. First, these candidates are tested for their predictive value for task performance and satisfaction without task-related semantics to reduce bias from low task-interaction congruence. After the first experiment showed that only flow predicts performance and satisfaction, the second experiment tests flow, performance, and satisfaction in a realistic analytics scenario to improve external validity. The results suggest that flow experience might be a promising estimate for performance and satisfaction and thus quality of the immersive analytics tool.

The inquiry into the impact of diverse transitions between cross-reality environments on user experience remains a compelling research endeavor. Existing work often offers fragmented perspectives on various techniques or confines itself to a singular segment of the reality-virtuality spectrum, be it virtual reality or augmented reality. This study embarks on bridging this knowledge gap by systematically assessing the effects of six prevalent transitions while users remain immersed in tasks spanning both virtual and physical domains. In particular, we investigate the effect of different transitions while the user is continuously engaged in a demanding task instead of purely focusing on a given transition. As a preliminary step, we evaluate these six transitions within the realm of pure virtual reality to establish a baseline. Our findings reveal a clear preference among participants for brief and efficient transitions in a task-driven experience, instead of transitions that prioritize interactivity and continuity. Subsequently, we extend our investigation into a cross-reality context, encompassing transitions between virtual and physical environments. Once again, our results underscore the prevailing preference for concise and effective transitions. Furthermore, our research offers intriguing insights about the potential mitigation of visual incoherence between virtual and augmented reality environments by utilizing different transitions.

The use of multi-robot systems is a field that can benefit from VR by strengthening understanding of the situation and enabling seamless interaction with the actors involved. This work investigates how the usability of a design for interaction with a multi-robot system for ship maintenance is assessed. Furthermore, comments from the participants are consulted as impulses for improving the design.

The use of robust software engineering processes is essential in the design and development of interactive systems. This ensures that software is both functionally correct and also usable in the required context. There are a variety of software engineering techniques that can be used to consider different aspects of a system under construction, and at different stages in the development process. There is, however, a natural tension between formal approaches (typically used in the domain of safety-critical systems to consider functional correctness) and informal design approaches, which focus on users and user requirements in a manner which is accessible by stakeholders. In this paper we present two new approaches which enable a tighter coupling of informal design requirements with formal models. We present examples of these two approaches and discuss the benefits that transformations between the informal and formal provide. We also discuss the current limitations of such work along with recommendations about how these might be addressed.

Gathering qualitative user data in a user-centered design process is one of the very early steps to create interactive systems. However, generating structured models from qualitative data towards descriptions that can be used for the implementation of interactive systems and prototypes raises various challenges, such as a strong influence of the modeler's knowledge and their interpretation of the gathered qualitative data. Introducing the modeler's bias may result in a system implementation which does not fully represent the information provided in the original qualitative data, generating an unwanted gap between what the user needs and what the system provides.To address this challenge, in this paper we present a structured and manual transformation method, which enables a modeler to create BPMN models from interview data by reducing the modeler's individual influence on the resulting BPMN model. We evaluate this approach in the context of the implementation of persuasive systems, which should support changing unwanted work-related habits. Therefore, we conducted unstructured interviews with office workers, thinking aloud interviews, in which we asked office workers to imagine a situation where they showed an unwanted work-related habit and to describe this habit together with an alternative behavior. In a quantitative experimental study, we then asked study participants to create BPMN models either with or without our new transformation method.Our analyses showed that when using our method, different participants created very similar BPMN models of the habits, even with little training. We conclude that the major contribution of our work is that the presented method can be applied to the creation of structured models from unstructured interview data. This method that makes use of rich interview data is suitable for the design and implementation of interactive systems.

The change of the user's viewpoint in an immersive virtual environment, called locomotion, is one of the key components in a virtual reality interface. Effects of locomotion, such as simulator sickness or disorientation, depend on the specific design of the locomotion method and can influence the task performance as well as the overall acceptance of the virtual reality system. Thus, it is important that a locomotion method achieves the intended effects. The complexity of this task has increased with the growing number of locomotion methods and design choices in recent years. Locomotion taxonomies are classification schemes that group multiple locomotion methods and can aid in the design and selection of locomotion methods. Like locomotion methods themselves, there exist multiple locomotion taxonomies, each with a different focus and, consequently, a different possible outcome. However, there is little research that focuses on locomotion taxonomies. We performed a systematic literature review to provide an overview of possible locomotion taxonomies and analysis of possible decision criteria such as impact, common elements, and use cases for locomotion taxonomies. We aim to support future research on the design, choice, and evaluation of locomotion taxonomies and thereby support future research on virtual reality locomotion.

Operators’ well-being is a key factor for the success of industrial production processes. Even though research has studied the well-being aspects of the industry, such as support and improvement of ergonomics, there is still a long way to go to achieve a sustainable and healthy work context for manufacturing industry. We believe the Human-Computer Interaction community can contribute by developing research on worker well-being in real-life settings. This workshop intends to offer a venue for HCI researchers that focus on worker well-being for the manufacturing industry and other industry domains.

Embodied locomotion, especially leaning, has one major problem. Effectively the regular functionality of the utilized body parts is overwritten. Thus, in this work, we propose 6 different status control methods that seamlessly switch off (brake) a seated leaning locomotion interface. Different input modalities, such as a physical button, voice, and gestures/metaphors, are used and evaluated against a baseline condition and a leaning interface with a bilateral transfer function. In a user study, participants were encouraged, but not forced to use these interfaces. They did, and the most diegetic interface, a hover-board metaphor, was the most preferred. However, the overall results are more heterogeneous and the interfaces vary in their suitability for different applications/scenarios. Therefore, we summarized the results in a guideline.

Psychological factors to be assessed by questionnaires, such as presence, may be influenced by variables like a break in presence induced by transitioning between physical and virtual reality - or time elapsed between the actual sensation and its measurement when questionnaires are used. Moreover, participants of previous experiments stated discomfort due to changing repeatedly between VR and non-VR. These aspects motivate the investigation of new ways of administering questionnaires in VR research. Previous attempts to integrate questionnaires into VR as world- or user-anchored canvases still lead to a clear separation between interaction for task and data acquisition in the virtual environment, which has been shown as problematic due to interruption of experience. Therefore, this work goes one step further by integrating the answering of the questionnaire into the actual task using the same interaction technique and metaphor. We implemented a bow and arrow game in which the player had to shoot at randomly spawning targets as fast and accurate as possible. Subsequently, the player had to answer each item of a questionnaire by actually shooting at a target that represented the rating with the same type of interaction method. No difference in presence (SUS-PQ), satisfaction (ASQ) or workload (SMEQ) ratings was found between questionnaires presented either embedded in VR (as described above), as text panel in VR or as desktop PC version. In conclusion, the embedded questionnaires may render less negative effects of transitioning between VR and non-VR without impairing the questionnaire results.

Continuous virtual rotation is likely one of the biggest contributors to cybersickness, while simultaneously being necessary for many VR scenarios where the user, for instance, is sitting in a bus, at an office desk, or on a couch and therefore, limited in physical body rotation. A possible solution is discrete virtual rotation, such as already broadly accepted in translational movements (teleportation). In this work, we want to help increase the knowledge about discrete virtual rotations. We classify existing work and systematically investigate the two dimensionstarget(rotation)acquisition(selectionvs. directional)and body-based (yes vs. no) regarding their impact on the performance in a naive and a primed rotational search task, spatial orientation, and usability. We do find the novel virtual rotation selection most successful in both search tasks and no difference in the factor bodybased on spatial orientation.

Virtual Reality is increasingly used for safe evaluation and validation of autonomous vehicles by automotive engineers. However, the design and creation of virtual testing environments is a cumbersome process. Engineers are bound to utilize desktop-based authoring tools, and a high level of expertise is necessary. By performing scene authoring entirely inside VR, faster design iterations become possible. To this end, we propose a VR authoring environment that enables engineers to design road networks and traffic scenarios for automated vehicle testing based on free-hand interaction. We present a 3D interaction technique for the efficient placement and selection of virtual objects that is employed on a 2D panel. We conducted a comparative user study in which our interaction technique outperformed existing approaches regarding precision and task completion time. Furthermore, we demonstrate the effectiveness of the system by a qualitative user study with domain experts.

Abstract This editorial introduces the special issue of Interacting with Computer on Heterogeneous Models and Modelling Approaches for Engineering of Interactive Systems. This special issue was proposed to gather the best contributions from a series of workshops organized alongside conferences such as FM’19 (3rd World Congress on Formal Methods) and EICS’19 (11th ACM SIGCHI Symposium on Engineering Interactive Computing Systems). It also encompasses papers submitted directly to this special issue.

Task models have been used for decades in interactive system design and there are several mature modelling approaches with corresponding tool support. However, in our own work, we have also experienced their limitations, especially in situations where task models are partial ancillary models and not primary artifacts. This was one of the motivations for this paper, which presents a systematic examination of literature to better understand the current place of task models in the continual evolution of user-centred software development practices. While overview work in this domain typically focuses on the analysis of representative task modelling notations and/or tools and relies on foundation papers, we apply a mixed top-down and bottom-up approach to identify relevant themes and trends in the use of task models over the last twenty-years. The paper identifies and discusses dominant patterns of use as well as gaps. It provides a comprehensive framing of both past and present trends in task modelling and supports those who want to incorporate task modelling in their own work. From this we identify areas of research that should receive greater attention in order to address future considerations.

Leaning (the upper body) has several times been shown to be a suitable virtual travel technique when being seated; in both, flying as well as ground-based scenarios. The direction of the steering method most commonly used is gaze/head-directed. However, this does not allow to inspect the environment independently from the direction of movement. The change to torso-directed steering allows for the latter and additionally does not take anything from the natural character of the leaning metaphor. We empirically investigated the impact of this freedom in a ground-based scenario and complemented the conditions with a virtual body-directed method and then crossed all with device-based control conditions. In the conducted study (n = 25), we found the torso-directed methods objectively performed the best (traveled distance, completion time & number of collisions), and found torso-directed leaning subjectively rated the most usable one.

Benjamin Weyersa* , Barbara Frankb & Annette Klugeb a Human-Computer Interaction, University of Trier, Trier, Germanyb Department of Work and Organizational Psychology, Ruhr-University Bochum, Bochum, GermanyBenjamin Weyers is currently Assistant Professor at University of Trier and Head of the Human-Computer Interaction Group. Before, he was PostDoc at the Virtual Reality and Immersive Visualization group at RWTH Aachen University. He received his PhD in 2011 at the University of Duisburg-Essen and joined RWTH in 2013. He is interested in the development and research on interactive analysis methods for abstract and scientific data using immersive systems as well as the integration of VR and AR into the control of technical systems for the support of human users in semi-automated control scenarios. Additionally, he focuses on the development and use of formal methods for the description of interactive systems.Barbara Frank obtained her PhD in 2017 at the Department of Work, Organizational and Business Psychology at Ruhr University Bochum. She holds a Master of Science in Applied Cognitive and Media Science. Her research focused on various methods for complex cognitive skill retention and impact of individual factors on skill retention. Barbara Frank is currently working in the field of HR-IT at ThyssenKrupp, Essen.Annette Kluge is a Full Professor for Work, Organizational and Business Psychology at the Ruhr University Bochum, Germany. She obtained her Diploma in Work and Organizational Psychology at the Technical University Aachen and her doctorate in ergonomics and vocational training at the University of Kassel, Germany in 1994. Her expertise is in Human Factors and Ergonomics, training science, skill acquisition and retention, safety management and organizational learning from errors and organizational forgetting.CONTACT Benjamin Weyers [email protected] Human-Computer Interaction, University of Trier, Trier, Germany.Color versions of one or more of the figures in the article can be found online at www.tandfonline.com/hihc.ABSTRACTThis paper presents a comprehensive formal engineering approach for the development of gaze guiding as an adaptive computer-based job aid to support semi-automated technical control tasks. Major requirement for this engineering method was to present a model-based approach, which on the one hand offers a coherent integration of various heterogeneous descriptions of the system, the standard operating procedures to be applied, and the used gaze guiding, and an algorithmic transformation into an executable form on the other. The latter is used as part of a runtime system or execution framework that integrates gaze guiding into an existing graphical user interface as an overlay. To demonstrate the suitability of the resulting model that enables gaze guiding, we present a use case for the modeling approach and we conducted a user study with 140 participants who worked on three different types of SOPs. The study showed the positive impact of the gaze guiding and its potential to suite as an adaptive computer-based job aid. The results confirmed findings from previous studies and showed decreased numbers of errors during the execution of the start-up procedure if gaze guiding was used.

Embodied conversational agents become more and more important in various virtual reality applications, e.g., as peers, trainers or therapists. Besides their appearance and behavior, appropriate speech is required for them to be perceived as human-like and realistic. Additionally to the used voice signal, also its auralization in the immersive virtual environment has to be believable. Therefore, we investigated the effect of adding directivity to the speech sound source. Directivity simulates the orientation dependent auralization with regard to the agent's head orientation. We performed a one-factorial user study with two levels (n=35) to investigate the effect directivity has on the perceived social presence and realism of the agent's voice. Our results do not indicate any significant effects regarding directivity on both variables covered. We account this partly to an overall too low realism of the virtual agent, a not overly social utilized scenario and generally high variance of the examined measures. These results are critically discussed and potential further research questions and study designs are identified.

The 10th annual IEEE 3DUI Contest focuses on the development of 3D User Interfaces (3DUIs) using passive haptic feedback in Mixed Reality Environments. Material properties of real objects are enhanced with virtual behaviors while used for interaction in a mixed reality scenario. The contest was open to anyone interested in 3DUIs, from researchers to students, enthusiasts, and professionals. The purpose of the contest is to stimulate innovative and creative solutions to challenging 3DUI problems.

In this work, we evaluate the impact of passive haptic feedback on touch-based menus, given the constraints and possibilities of a seated, desk-based scenario in VR. Therefore, we compare a menu that once is placed on the surface of a desk and once mid-air on a surface in front of the user. The study design is completed by two conditions without passive haptic feedback. In the conducted user study (n=33), we found effects of passive haptics (present vs-non-present) and menu alignment (desk vs. mid-air) on the task performance and subjective look & feel. However, the race between the conditions was close. An overall winner was the mid-air menu with passive haptic feedback, which however raises hardware requirements.

In this work, we evaluate the feasibility of an office desk substitution in the context of a visual data analysis task involving travel. We measure the impact on cybersickness as well as the general task performance and presence. In the conducted user study (n=52), surprisingly, and partially in contradiction to existing work, we found no significant differences for those core measures between the control condition without a virtual table and the condition containing a virtual table.

The ongoing migration of HMDs to the consumer market also allows the integration of immersive environments into analysis workflows that are often bound to an (office) desk. However, a critical factor when considering VR solutions for professional applications is the prevention of cybersickness. In the given scenario the user is usually seated and the surrounding real world environment is very dominant, where the most dominant part is maybe the desk itself. Including this desk in the virtual environment could serve as a resting frame and thus reduce cybersickness next to a lot of further possibilities. In this work, we evaluate the feasibility of a substitution like this in the context of a visual data analysis task involving travel, and measure the impact on cybersickness as well as the general task performance and presence. In the conducted user study ( n=52), surprisingly, and partially in contradiction to existing work, we found no significant differences for those core measures between the control condition without a virtual table and the condition containing a virtual table. However, the results also support the inclusion of a virtual table in desk-based use cases.

During free exploration of an unknown virtual scene, users often miss important parts, leading to incorrect or incomplete environment knowledge and a potential negative impact on performance in later tasks. This is addressed by wayfinding aids such as compasses, maps, or trails, and automated exploration schemes such as guided tours. However, these approaches either do not actually ensure exploration success or take away control from the user. Therefore, we present an interactive assistance interface to support exploration that guides users to interesting and unvisited parts of the scene upon request, supplementing their own, free exploration. It is based on an automated analysis of object visibility and viewpoint quality and is therefore applicable to a wide range of scenes without human supervision or manual input. In a user study, we found that the approach improves users' knowledge of the environment, leads to a more complete exploration of the scene, and is also subjectively helpful and easy to use.

The 9th annual IEEE 3DUI Contest focuses on the development of 3D User Interfaces (3DUIs) for three different tasks in fully immersive Virtual Environments (VEs): (1) Ladder Climbing, (2) First-Person View Flying, and (3) Tower Stacking. The 3DUI Contest is part of the 2018 IEEE Conference on Virtual Reality and 3D User Interfaces held in Reutlingen, Germany. The contest is open to anyone interested in 3DUIs, from researchers to students, enthusiasts, and professionals. The purpose of the contest is to stimulate innovative and creative solutions to challenging 3DUI problems.

Viewpoint quality estimation methods allow the determination of the most informative position in a scene. However, a single position usually cannot represent an entire scene, requiring instead a set of several viewpoints. Measuring the quality of such a set of views, however, is not trivial, and the computation of an optimal set of views is an NP-hard problem. Therefore, in this work, we propose three methods to estimate the quality of a set of views. Furthermore, we evaluate three approaches for computing an approximation to the optimal set (two of them new) regarding effectiveness and efficiency.

The manual adjustment of travel speed to cover medium or large distances in virtual environments may increase cognitive load, and manual travel at high speeds can lead to cybersickness due to inaccurate steering. In this work, we present an approach to quickly pass regions where the environment does not change much, using automated suggestions based on the computation of common visibility. In a user study, we show that our method can reduce cybersickness when compared with manual speed control.

Immersive visualization (IV) fosters the creation of mental images of a data set, a scene, a procedure, etc. We devise an initial version of a design space for categorizing workflows that take advantage of IV. From this categorization, specific requirements for an actual, seamless IV-integration can be derived. We validate the design space with three workflows investigated in our research projects.

The use of non-verbal vocal input (NVVI) as a hand-free trigger approach has proven to be valuable in previous work [7]. Nevertheless, BlowClick's original detection method is vulnerable to false positives and, thus, is limited in its potential use, e.g., together with acoustic feedback for the trigger. Therefore, we extend the existing approach by adding common machine learning methods. We found that a support vector machine (SVM) with Gaussian kernel performs best for detecting blowing with at least the same latency and more precision as before. Furthermore, we added acoustic feedback to the NVVI trigger, which increases the user's confidence. To evaluate the advanced trigger technique, we conducted a user study (n = 33). The results confirm that it is a reliable trigger; alone and as part of a hands-free point-and-click interface.

To use the full potential of immersive data analysis when wearing a head-mounted display, the user has to be able to navigate through the spatial data. We collected, developed and evaluated 5 different handsfree navigation methods that are usable while seated in the analyst's usual workplace. All methods meet the requirements of being easy to learn and inexpensive to integrate into existing workplaces. We conducted a user study with 23 participants which showed that a body leaning metaphor and an accelerometer pedal metaphor performed best within the given task.

Abstract Interactive analysis of 3D relational data is challenging. A common way of representing such data are node‐link diagrams as they support analysts in achieving a mental model of the data. However, naïve 3D depictions of complex graphs tend to be visually cluttered, even more than in a 2D layout. This makes graph exploration and data analysis less efficient. This problem can be addressed by edge bundling. We introduce a 3D cluster‐based edge bundling algorithm that is inspired by the force‐directed edge bundling (FDEB) algorithm [ HvW09b ] and fulfills the requirements to be embedded in an interactive framework for spatial data analysis. It is parallelized and scales with the size of the graph regarding the runtime. Furthermore, it maintains the edge's model and thus supports rendering the graph in different structural styles. We demonstrate this with a graph originating from a simulation of the function of a macaque brain.

When moving through a tracked immersive virtual environment, it is sometimes useful to deviate from the normal one-to-one mapping of real to virtual motion. One option is the application of rotation gain, where the virtual rotation of a user around the vertical axis is amplified or reduced by a factor. Previous research in head-mounted display environments has shown that rotation gain can go unnoticed to a certain extent, which is exploited in redirected walking techniques. Furthermore, it can be used to increase the effective field of regard in projection systems. However, rotation gain has never been studied in CAVE systems, yet. In this work, we present an experiment with 87 participants examining the effects of rotation gain in a CAVE-like virtual environment. The results show no significant effects of rotation gain on simulator sickness, presence, or user performance in a cognitive task, but indicate that there is a negative influence on spatial knowledge especially for inexperienced users. In secondary results, we could confirm results of previous work and demonstrate that they also hold for CAVE environments, showing a negative correlation between simulator sickness and presence, cognitive performance and spatial knowledge, a positive correlation between presence and spatial knowledge, a mitigating influence of experience with 3D applications and previous CAVE exposure on simulator sickness, and a higher incidence of simulator sickness in women.

To avoid simulator sickness and improve presence in immersive virtual environments (IVEs), high frame rates and low latency are required. In contrast, volume rendering applications typically strive for high visual quality that induces high computational load and, thus, leads to low frame rates. To evaluate this trade-off in IVEs, we conducted a controlled user study with 53 participants. Search and count tasks were performed in a CAVE with varying volume rendering conditions which are applied according to viewer position updates corresponding to head tracking. The results of our study indicate that participants preferred the rendering condition with continuous adjustment of the visual quality over an instantaneous adjustment which guaranteed for low latency and over no adjustment providing constant high visual quality but rather low frame rates. Within the continuous condition, the participants showed best task performance and felt less disturbed by effects of the visualization during movements. Our findings provide a good basis for further evaluations of how to accelerate volume rendering in IVEs according to user's preferences.

Data annotation finds increasing use in Virtual Reality applications with the goal to support the data analysis process, such as architectural reviews. In this context, a variety of different annotation systems for application to immersive virtual environments have been presented. While many interesting interaction designs for the data annotation workflow have emerged from them, important details and evaluations are often omitted. In particular, we observe that the process of handling metadata to interactively create and manage complex annotations is often not covered in detail. In this paper, we strive to improve this situation by focusing on the design of data annotation workflows and their evaluation. We propose a workflow design that facilitates the most important annotation operations, i.e., annotation creation, review, and modification. Our workflow design is easily extensible in terms of supported annotation and metadata types as well as interaction techniques, which makes it suitable for a variety of application scenarios. To evaluate it, we have conducted a user study in a CAVE-like virtual environment in which we compared our design to two alternatives in terms of a realistic annotation creation task. Our design obtained good results in terms of task performance and user experience.

In this work, we report on a pilot study we conducted, and on a study design, to examine the effects and applicability of rotation gain in CAVE-like virtual environments. The results of the study will give recommendations for the maximum levels of rotation gain that are reasonable in algorithms for enlarging the virtual field of regard or redirected walking.

Controlling and observing complex systems is central to the study of human–machine interaction. In our understanding, there is much to be gained from integrating formal modeling and analysis, including the reconfiguration of user interfaces, with the development of user interfaces with high usability. To this end, we introduce a new approach to modeling and reconfiguration of user interfaces jointly with a newly developed set of tools for interactive and visual creation and automatic transformation of user interfaces' interaction logic to a formal language based on Petri nets. Reconfiguration will be embedded into a process for adapting user interfaces to the user's cognitive representation of the controlled system. This process involves practicing the use of a given user interface, adapting it to the user's needs through reconfiguration, and applying the resulting adaptations to the formally defined interaction logic. An evaluation study confirms that this process reduces errors in interaction.

In this paper we introduce CoBo, a collaborative system supporting cryptographic protocol learning, which offers an interface for the cooperative creation of concept keyboards. Concept keyboards are input interfaces created by the user during runtime with the goal of meeting the user's need for interaction. Experiments with an early version of CoBo have shown that, although students recognize the power of collaborative learning, they found a collaborative simulation of cryptographic algorithms should be associated with an additional step in the learning process: the collaborative design of the concept keyboards that will be used to perform the collaborative simulation of cryptographic protocols.