Spatialstrates: Cross-Reality Collaboration through Spatial HypermediaConsumer-level XR hardware now enables immersive spatial computing, yet most knowledge work remains confined to traditional 2D desktop environments. These worlds exist in isolation: writing emails or editing presentations favors desktop interfaces, while viewing 3D simulations or architectural models benefits from immersive environments. We address this fragmentation by combining spatial hypermedia, shareable dynamic media, and cross-reality computing to provide (1) composability of heterogeneous content and of nested information spaces through spatial transclusion, (2) pervasive cooperation across heterogeneous devices and platforms, and (3) congruent spatial representations despite underlying environmental differences. Our implementation, the Spatialstrates platform, embodies these principles using standard web technologies to bridge 2D desktop and 3D immersive environments. Through four scenarios—collaborative brainstorming, architectural design, molecular science visualization, and immersive analytics—we demonstrate how Spatialstrates enables collaboration between desktop 2D and immersive 3D contexts, allowing users to select the most appropriate interface for each task while maintaining collaborative capabilities.2025MBMarcel Borowski et al.Social & Collaborative VRMixed Reality WorkspacesPrototyping & User TestingUIST
Datamancer: Bimanual Gesture Interaction in Multi-Display Ubiquitous Analytics EnvironmentsWe introduce Datamancer, a wearable device enabling bimanual gesture interaction across multi-display ubiquitous analytics environments. Datamancer addresses the gap in gesture-based interaction within data visualization settings, where current methods are often constrained by limited interaction spaces or the need for installing bulky tracking setups. Datamancer integrates a finger-mounted pinhole camera and a chest-mounted gesture sensor, allowing seamless selection and manipulation of visualizations on distributed displays. By pointing to a display, users can acquire the display and engage in various interactions, such as panning, zooming, and selection, using both hands. Our contributions include (1) an investigation of the design space of gestural interaction for physical ubiquitous analytics environments; (2) a prototype implementation of the Datamancer system that realizes this model; and (3) an evaluation of the prototype through demonstration of application scenarios, an expert review, and a user study.2025BPBiswaksen Patnaik et al.University of Maryland College Park, Department of Computer ScienceFull-Body Interaction & Embodied InputInteractive Data VisualizationContext-Aware ComputingCHI
Towards Flexible and Robust User Interface Adaptations With Multiple ObjectivesThis paper proposes a new approach for online UI adaptation that aims to overcome the limitations of the most commonly used UI optimization method involving multiple objectives: weighted sum optimization. Weighted sums are highly sensitive to objective formulation, limiting the effectiveness of UI adaptations. We propose ParetoAdapt, an adaptation approach that uses online multi-objective optimization with a posteriori articulated preferences---that is, articulation of preferences after the optimization has concluded to make UI adaptation robust to incomplete and inaccurate objective formulations. It offers users a flexible way to control adaptations by selecting from a set of Pareto optimal adaptation proposals and adjusting them to fit their needs. We showcase the feasibility and flexibility of ParetoAdapt by implementing an online layout adaptation system in a state-of-the-art 3D UI adaptation framework. We further evaluate its robustness and run-time in simulation-based experiments that allow us to systematically change the accuracy of the estimated user preferences. We conclude by discussing how our approach may impact the usability and practicality of online UI adaptations.2023CJChristoph A. Johns et al.Mixed Reality Workspaces360° Video & Panoramic ContentComputational Methods in HCIUIST
Collectives and Their Artifact EcologiesComputing today happens across multiple devices, applications, users, organizational units, and in the rest of the world outside. Groups and communities come together for different reasons and operate within contexts that may differ from dominant modes of production and consumption. With a foundation in activity theoretical HCI we develop the concept of collective artifact ecologies. This concept enables us to identify struggles of collective use of computational devices today, delimiting collective artifact ecologies in order to study and explain how they develop and overlap. Through an analysis of three empirical cases, we illustrate the notion of collectives and how they face challenges in establishing, maintaining and negotiating their artifact ecologies. This paper, therefore, contributes a theoretical foundation for analyzing groups and communities as collectives, with a particular emphasis on the multiple tools and artifacts they use. To serve as a starting point for further engagement with these concepts, we have provided a number of guiding questions to support the understanding of collective artifact ecologies.2022HKHenrik Korsgaard et al.Team Collaboration; Team CollaborationCSCW
Caught in the Network: The Impact of WhatsApp's 2021 Privacy Policy Update on Users' Messaging App EcosystemsIn January 2021, WhatsApp announced an update to their privacy policy, sparking an outcry that saw millions of users install other messaging apps such as Telegram and Signal. This presented a rare opportunity to study users’ experiences when trying to leave the world’s most popular communication app. We conducted surveys in February and May with 1525 WhatsApp users from Mexico, Spain, South Africa, and the United Kingdom. Over a quarter wanted to switch at least part of their communication to other apps, but 74% of them failed to do so. By May, 27% had increased their use of other apps, and only 16% used WhatsApp less. Beyond network effects, users struggled with making informed choices of alternative apps and with differences in their design and functionality. We suggest messaging interoperability as an approach to alleviate switching costs and discuss implications for HCI research and competition regulation of digital services.2022CGCarla Griggio et al.Aarhus UniversityPrivacy by Design & User ControlPrivacy Perception & Decision-MakingSocial Platform Design & User BehaviorCHI
Putting Down Roots: Exploring the Placeness of Virtual Collections in Public LibrariesIn this pictorial, we investigate how a virtual collection can put down its roots in a physical space and integrate into the local community. We present PLACED, a place-centric digital service that supports participation and community-production of knowledge in library events. We illustrate how PLACED has been deployed and used at a local public library over a six-month period. We examine the community-produced virtual collection that grew out of this library event with a focus on its placeness.2020DYDaisy Yoo et al.Misinformation & Fact-CheckingCommunity Collaboration & WikipediaCommunity Engagement & Civic TechnologyDIS
"In VR, everything is possible!": Sketching and Simulating Spatially-Aware Interactive Spaces in Virtual RealityWe propose using virtual reality (VR) as a design tool for sketching and simulating spatially-aware interactive spaces. Using VR, designers can quickly experience their envisioned spaces and interactions by simulating technologies such as motion tracking, multiple networked devices, or unusual form factors such as spherical touchscreens or bezel-less display tiles. Design ideas can be rapidly iterated without restrictions by the number, size, or shape and availability of devices or sensors in the lab. To understand the potentials and challenges of designing in VR, we conducted a user study with 12 interaction designers. As their tool, they used a custom-built virtual design environment with finger tracking and physics simulations for natural interactions with virtual devices and objects. Our study identified the designers' experience of space in relation to their own bodies and playful design explorations as key opportunities. Key challenges were the complexities of building a usable yet versatile VR-based "World Editor".2020HJHans-Christian Jetter et al.University of Applied Sciences Upper AustriaFull-Body Interaction & Embodied InputMixed Reality WorkspacesComputational Methods in HCICHI
Vistribute: Distributing Interactive Visualizations in Dynamic Multi-Device SetupsWe present Vistribute, a framework for the automatic distribution of visualizations and UI components across multiple heterogeneous devices. Our framework consists of three parts: (i) a design space considering properties and relationships of interactive visualizations, devices, and user preferences in multi-display environments; (ii) specific heuristics incorporating these dimensions for guiding the distribution for a given interface and device ensemble; and (iii) a web-based implementation instantiating these heuristics to automatically generate a distribution as well as providing interaction mechanisms for user-defined adaptations. In contrast to existing UI distribution systems, we are able to infer all required information by analyzing the visualizations and devices without relying on additional input provided by users or programmers. In a qualitative study, we let experts create their own distributions and rate both other manual distributions and our automatic ones. We found that all distributions provided comparable quality, hence validating our framework.2019THTom Horak et al.Technische Universität DresdenInteractive Data VisualizationContext-Aware ComputingCHI
Cross-Device Taxonomy: Survey, Opportunities and Challenges of Interactions Spanning Across Multiple DevicesDesigning interfaces or applications that move beyond the bounds of a single device screen enables new ways to engage with digital content. Research addressing the opportunities and challenges of interactions with multiple devices in concert is of continued focus in HCI research. To inform the future research agenda of this field, we contribute an analysis and taxonomy of a corpus of 510 papers in the cross-device computing domain. For both new and experienced researchers in the field we provide: an overview, historic trends and unified terminology of cross-device research; discussion of major and under-explored application areas; mapping of enabling technologies; synthesis of key interaction techniques spanning across multiple devices; and review of common evaluation strategies. We close with a discussion of open issues. Our taxonomy aims to create a unified terminology and common understanding for researchers in order to facilitate and stimulate future cross-device research.2019FBFrederik Brudy et al.University College LondonKnowledge Management & Team AwarenessContext-Aware ComputingUbiquitous ComputingCHI
AdaM: Adapting Multi-User Interfaces for Collaborative Environments in Real-TimeDeveloping cross-device multi-user interfaces (UIs) is a challenging problem. There are numerous ways in which content and interactivity can be distributed. However, good solutions must consider multiple users, their roles, their preferences and access rights, as well as device capabilities. Manual and rule-based solutions are tedious to create and do not scale to larger problems nor do they adapt to dynamic changes, such as users leaving or joining an activity. In this paper, we cast the problem of UI distribution as an assignment problem and propose to solve it using combinatorial optimization. We present a mixed integer programming formulation which allows real-time applications in dynamically changing collaborative settings. It optimizes the allocation of UI elements based on device capabilities, user roles, preferences, and access rights. We present a proof-of-concept designer-in-the-loop tool, allowing for quick solution exploration. Finally, we compare our approach to traditional paper prototyping in a lab study.2018SPSeonwook Park et al.ETH ZurichMixed Reality WorkspacesCreative Collaboration & Feedback SystemsCHI
Remediating a Design Tool: Implications of Digitizing Sticky NotesSticky notes are ubiquitous in design processes because of their tangibility and ease of use. Yet, they have well-known limitations in professional design processes, as documentation and distribution are cumbersome at best. This paper compares the use of sticky notes in ideation with a remediated digital sticky notes setup. The paper contributes with a nuanced understanding of what happens when remediating a physical design tool into digital space, by emphasizing focus shifts and breakdowns caused by the technology, but also benefits and promises inherent in the digital media. Despite users' preference for creating physical notes, handling digital notes on boards was easier and the potential of proper documentation make the digital setup a possible alternative. While the analogy in our remediation supported a transfer of learned handling, the users' experiences across technological setups impact their use and understanding, yielding new concerns regarding cross-device transfer and collaboration.2018MJSøren Qvist Jensen et al.Aarhus UniversityCustomizable & Personalized ObjectsPrototyping & User TestingCHI
The Application and Its Consequences for Non-Standard Knowledge WorkApplication-centric computing dominates human-computer interactions, yet the concept of an application is ambiguous and the impact of its ubiquity underexplored. We unpack "the application" through the lens of non-standard knowledge work: freelance, self-employed, and fixed-term contract workers who create knowledge in collaboration with a wide variety of stakeholders on a per-project basis. Based on interviews with fourteen participants we describe how: i) their economic value is intertwined with data and skills related to specific applications; ii) their access to this value is systematically jeopardised in collaboration due to the different application practices, preferences, and proficiencies of other stakeholders; and iii) they mitigate the costs of this compromise through cross-application collaboration strategies. We trace these experiences to common characteristics of applications, such as update processes, interface symmetries, application-document relationships, and operating system and hardware dependencies. By empirically and analytically focusing on "the application", we reveal the implications of the current application-centric computing paradigm and discuss how variations within this model create qualitatively different human-computer interactions.2018MNMidas Nouwens et al.Aarhus UniversityKnowledge Worker Tools & WorkflowsImpact of Automation on WorkCHI
PolarTrack: Optical Outside-In Device Tracking that Exploits Display PolarizationPolarTrack is a novel camera-based approach to detecting and tracking mobile devices inside the capture volume. In PolarTrack, a polarization filter continuously rotates in front of an off-the-shelf color camera, which causes the displays of observed devices to periodically blink in the camera feed. The periodic blinking results from the physical characteristics of current displays, which shine polarized light either through an LC overlay to produce images or through a polarizer to reduce light reflections on OLED displays. PolarTrack runs a simple detection algorithm on the camera feed to segment displays and track their locations and orientations, which makes PolarTrack particularly suitable as a tracking system for cross-device interaction with mobile devices. Our evaluation of PolarTrack's tracking quality and comparison with state-of-the-art camera-based multi-device tracking showed a better tracking accuracy and precision with similar tracking reliability. PolarTrack works as standalone multi-device tracking but is also compatible with existing camera-based tracking systems and can complement them to compensate for their limitations.2018RRRoman Rädle et al.Aarhus UniversityHand Gesture RecognitionContext-Aware ComputingUbiquitous ComputingCHI