Cross Reality (CR) is a new emerging field based on the current developments in Mixed Reality hardware, especially supported by the broad market penetration of video-based see-through Head-Mounted Displays. It refers to applications that span across different stages (real, Augmented Reality, Augmented Virtuality, Virtual Reality) of the reality-virtuality continuum, where users are interconnected between different stages and/or are able to transition between these stages. This publication follows the concept of other grand challenges publications and reflects the discussion of various researchers invested in CR. After an initial discussion at the 1stJoint Workshop on Cross Reality at IEEE ISMAR 2023, six topic groups have been identified, leading to 22 challenges, which were discussed in groups over the period of multiple months. The discussion of these challenges should act as a road map for future research in the area of CR.

The paper summarizes the contributions to the AVI 2024 workshop on Prototyping and Developing Real-World Applications of Extended Reality.

Recent Head-Mounted Displays enable users to perceive the real environment using a video-based see-through mode and the fully virtual environment within a single display. Leveraging these advancements, we present a generic concept to seamlessly transition between the real and virtual environment, with the goal of supporting users in engaging with and disengaging from any real environment into Virtual Reality. This transition process uses a digital replica of the real environment and incorporates various stages of Milgram’s Reality-Virtuality Continuum, along with visual transitions that facilitate gradual navigation between them. We implemented the overall transition concept and four object-based transition techniques. The overall transition concept and four techniques were evaluated in a qualitative user study, focusing on user experience, the use of the replica and visual coherence.

Abstract User evaluation is a common and useful tool for systematically generating knowledge and validating novel approaches in the domain of Immersive Analytics. Since this research domain centres around users, user evaluation is of extraordinary relevance. Additionally, Immersive Analytics is an interdisciplinary field of research where different communities bring in their own methodologies. It is vital to investigate and synchronise these different approaches with the long‐term goal to reach a shared evaluation framework. While there have been several studies focusing on Immersive Analytics as a whole or on certain aspects of the domain, this is the first systematic review of the state of evaluation methodology in Immersive Analytics. The main objective of this systematic literature review is to illustrate methodologies and research areas that are still underrepresented in user studies by identifying current practice in user evaluation in the domain of Immersive Analytics in coherence with the PRISMA protocol. (see https://www.acm.org/publications/class-2012 )

Collaboration is a key aspect of immersive visual data analysis. Due to its inherent benefit of seeing co-located collaborators, augmented reality is often useful in such collaborative scenarios. However, to enable the augmentation of the real environment, there are different types of technology available. While there are constant developments in specific devices, each of these device types provide different premises for collaborative visual data analysis. In our work we combine handheld, optical see-through and video see-through displays to explore and understand the impact of these different device types in collaborative immersive analytics. We conducted a mixed-methods collaborative user study where groups of three performed a shared data analysis task in augmented reality with each user working on a different device, to explore differences in collaborative behaviour, user experience and usage patterns. Both quantitative and qualitative data revealed differences in user experience and usage patterns. For collaboration, the different display types influenced how well participants could participate in the collaborative data analysis, nevertheless, there was no measurable effect in verbal communication.

Cross-Virtuality applications enabling users to move between different stages of Milgram’s reality-virtuality continuum are a rapidly growing field of research. Modern video see-through head-mounted displays allow users to switch between augmented and virtual reality without removing the headset. This enables for the first time a fluent transition between augmented and virtual reality. Based on insights from literature and preliminary experiments we designed and implemented four transitions: Fade, SimpleCut, TeleportBeam and Portal. These techniques were expected to represent the best suitable concepts for transitioning seamlessly between augmented and virtual reality. After incorporating results from a pre-study, the transition techniques were evaluated in a qualitative user study regarding user experience, simulator sickness, continuity and applicability. Participants were able to freely move between both realities during the study in an immersive analytics scenario for logistics data. In the user study, users preferred Fade in a workplace setting due to its efficiency and simplicity when transitioning frequently between realities. The Portal technique was deemed visually exciting and suitable for infrequent transitions between realities that differ greatly.

Abstract Cross‐virtuality analytics (XVA) is a novel field of research within immersive analytics and visual analytics. A broad range of heterogeneous devices across the reality–virtuality continuum, along with respective visual metaphors and analysis techniques, are currently becoming available. The goal of XVA is to enable visual analytics that use transitional and collaborative interfaces to seamlessly integrate different devices and support multiple users. In this work, we take a closer look at XVA and analyse the existing body of work for an overview of its current state. We classify the related literature regarding ways of establishing cross‐virtuality by interconnecting different stages in the reality–virtuality continuum, as well as techniques for transitioning and collaborating between the different stages. We provide insights into visualization and interaction techniques employed in current XVA systems. We report on ways of evaluating such systems, and analyse the domains where such systems are becoming available. Finally, we discuss open challenges in XVA, giving directions for future research.

Immersive Analytics is a quickly evolving field that unites several areas such as visualisation, immersive environments, and human-computer interaction to support human data analysis with emerging technologies. This research has thrived over the past years with multiple workshops, seminars, and a growing body of publications, spanning several conferences. Given the rapid advancement of interaction technologies and novel application domains, this paper aims toward a broader research agenda to enable widespread adoption. We present 17 key research challenges developed over multiple sessions by a diverse group of 24 international experts, initiated from a virtual scientific workshop at ACM CHI 2020. These challenges aim to coordinate future work by providing a systematic roadmap of current directions and impending hurdles to facilitate productive and effective applications for Immersive Analytics.