We introduce the notion of an Active Proxy interface, i.e. tangible models as proxies for physical data referents, supporting interactive exploration of data through active manipulation. We realise an active proxy data visualisation system, “MarioChart", using robot carts relocating themselves on a tabletop, e.g., to align with their data referents in a map or other visual layout. We consider a casual-data exploration scenario involving a multivariate campus sustainability dataset, using scale models as proxies for their physical building data referents. Our empirical study (n=12) compares active proxy use with conventional tablet interaction, finding that our active proxy system enhances short-term spatial memory of data and enables faster completion of certain data analytic tasks. It shows no significant differences compared to traditional touchscreens in long-term memory, physical fatigue, mental workload, or user engagement. Our study offers an initial baseline for active proxy techniques and advances understanding of tangible interfaces in situated data visualisation.

While visual channels (e.g., color, shape, size) have been explored for visualizing data in data physicalizations, there is a lack of understanding regarding how to encode data into physical material properties (e.g., roughness, hardness). This understanding is critical for ensuring data is correctly communicated and for potentially extending the channels and bandwidth available for encoding that data. We present a method to encode ordinal data into roughness, validated through user studies. In the first study, we identified just noticeable differences in perceived roughness from this method. In the second study, we 3D-printed proof of concepts for five different multivariate physicalizations using the model. These physicalizations were qualitatively explored (N=10) to understand people’s comprehension and impressions of the roughness channel. Our findings suggest roughness may be used for certain types of data encoding, and the context of the data can impact how people interpret roughness mapping direction.

Augmented Reality (AR) is touted to be beneficial in supporting situated information display, allowing virtual information panels to be overlaid on real-world scenes. People must then use their spatial memory to navigate among these virtual panels effectively. While spatial memory has been studied in physical environments (wall displays) and virtual reality environments, there has been little research on how physical surroundings might affect memorisation of virtual content in a mixed environment like AR. Therefore, we provide the first AR study of spatial memory, comparing two different room settings with two different situated layouts of virtual targets on an abstract spatial memory task. We find that participants recall spatial patterns with greater accuracy and higher subjective ratings in a room with furniture compared to an empty room. Our findings lead to important design implications for mixed-reality user interfaces, particularly in information-rich applications like situated analytics and small-multiples information visualisation.

Automatic layout optimisation allows users to arrange augmented reality content in the real-world environment without the need for tedious manual interactions. This optimisation is often based on modelling the intended content placement as constraints, defined as cost functions. Then, applying a cost minimization algorithm leads to a desirable placement. However, such an approach is limited by the lack of user control over the optimisation results. In this paper we explore the concept of user-driven constraints for augmented reality layout optimisation. With our approach users can define and set up their own constraints directly within the real-world environment. We first present a design space composed of three dimensions: the constraints, the regions of interest and the constraint parameters. Then we explore which input gestures can be employed to define the user-driven constraints of our design space through a user elicitation study. Using the results of the study, we propose a holistic system design and implementation demonstrating our user-driven constraints, which we evaluate in a final user study where participants had to create several constraints at the same time to arrange a set of virtual contents.

Existing situated visualization models assume the user is able to directly interact with the objects and spaces to which the data refers (known as physical referents). We review a growing body of work exploring scenarios where the user interacts with a proxy representation of the physical referent rather than immediately with the object itself. This introduces a complex mixture of immediate situatedness and proxies of situatedness that goes beyond the expressiveness of current models. We propose an extended model of situated visualization that encompasses Immediate Situated Visualization and ProxSituated (Proxy of Situated) Visualization. Our model describes a set of key entities involved in proxSituated scenarios and important relationships between them. From this model, we derive design dimensions and apply them to existing situated visualization work. The resulting design space allows us to describe and evaluate existing scenarios, as well as to creatively generate new conceptual scenarios.

Immersive analytics research has explored how embodied data representations and interactions can be used to engage users in sensemaking. Prior research has broadly overlooked the potential of immersive space for supporting analytic provenance, the understanding of sensemaking processes through users’ interaction histories. We propose the concept of embodied provenance, the use of three-dimensional space and embodied interactions in supporting recalling, reproducing, annotating and sharing analysis history in immersive environments. We design a conceptual framework for embodied provenance by highlighting a set of design criteria for analytic provenance drawn from prior work and identifying essential properties for embodied provenance. We develop a prototype system in virtual reality to demonstrate the concept and support the conceptual framework by providing multiple data views and embodied interaction metaphors in a large virtual space. We present a use case scenario of energy consumption analysis and evaluated the system through a qualitative evaluation with 17 participants, which show the system’s potential for assisting analytic provenance using embodiment. Our exploration of embodied provenance through this prototype provides lessons learnt to guide the design of immersive analytic tools for embodied provenance.

Head-mounted augmented reality (AR) displays allow for the seamless integration of virtual visualisation with contextual tangible references, such as physical (tangible) globes. We explore the design of immersive geospatial data visualisation with AR and tangible globes. We investigate the “tangible-virtual interplay” of tangible globes with virtual data visualisation, and propose a conceptual approach for designing immersive geospatial globes. We demonstrate a set of use cases, such as augmenting a tangible globe with virtual overlays, using a physical globe as a tangible input device for interacting with virtual globes and maps, and linking an augmented globe to an abstract data visualisation. We gathered qualitative feedback from experts about our use case visualisations, and compiled a summary of key takeaways as well as ideas for envisioned future improvements. The proposed design space, example visualisations and lessons learned aim to guide the design of tangible globes for data visualisation in AR.

Recent research in immersive visualisations has explored the use of physical 3D models together with virtual data visualisations, with a simple data encoding. However, little is known about how this technique could be extended towards more complex multivariate data with multiple charts. We present augmented scale models, immersive visualisations that place charts of multivariate data via Augmented Reality (AR) registered to physical 3D models. We identified two main factors for presenting AR charts in the limited display space around the models: 1) how charts are laid out (Slides vs Dashboard), and 2) how the chart views are arranged in the 3D space (On Scale Model, On Table, On Virtual Board). In a within-subject user study, we evaluated these two design considerations. We found that chart layout and view arrangement do not affect task error but do vary in response time. Dashboard and Slides perform equally well on simple tasks that require comparison of a single chart across scale models. However, in more complex tasks such as comparing multiple charts within a scale model or across several scale models, Dashboard shows no decrease in time performance, while Slides’s time performance decreases significantly. We also found that On Scale Model has the fastest performance, has good chart-scale model integration, and supports charts comparison well. On Table and On Virtual Board on the other hand, show a trade-off between the ability to support charts comparison across models and the chart-scale model integration.

We propose TimeTables, a novel prototype system that aims to support data exploration, using embodiment with space-time cubes in virtual reality. TimeTables uses multiple space-time cubes on virtual tabletops, which users can manipulate by extracting time layers or individual buildings to create new tabletop views. The surrounding environment includes a large space for multiple linked tabletops and a storage wall. TimeTables presents information at different time scales by stretching layers to drill down in time. Users can also jump into tabletops to inspect data from an egocentric perspective. We present a use case scenario of energy consumption displayed on a university campus to demonstrate how our system could support data exploration and analysis over space and time. From our experience and analysis we believe the system has a high potential in assisting spatio-temporal data exploration and analysis.

Geographic data visualisation on virtual globes is intuitive and widespread, but has not been thoroughly investigated. We explore two main design factors for quantitative data visualisation on virtual globes: i) commonly used primitives (2D bar, 3D bar, circle) and ii) the orientation of these primitives (tangential, normal, billboarded). We evaluate five distinctive visualisation idioms in a user study with 50 participants. The results show that aligning primitives tangentially on the globe’s surface decreases the accuracy of area-proportional circle visualisations, while the orientation does not have a significant effect on the accuracy of length-proportional bar visualisations. We also find that tangential primitives induce higher perceived mental load than other orientations. Guided by these results we design a novel globe visualisation idiom, Geoburst, that combines a virtual globe and a radial bar chart. A preliminary evaluation reports potential benefits and drawbacks of the Geoburst visualisation.

Visual exploration of maps often requires a contextual understanding at multiple scales and locations. Multiview map layouts, which present a hierarchy of multiple views to reveal detail at various scales and locations, have been shown to support better performance than traditional single-view exploration on desktop displays. This paper investigates the extension of such layouts of 2D maps into 3D immersive spaces, which are not limited by the real-estate barrier of physical screens and support sensemaking through spatial interaction. Based on our initial implementation of immersive multiview maps, we conduct an exploratory study with 16 participants aimed at understanding how people place and view such maps in immersive space. We observe the layouts produced by users performing map exploration search, comparison and route-planning tasks. Our qualitative analysis identifies patterns in layoutgeometry (spherical, spherical cap, planar),overview-detail relationship (central window, occluding, coordinated) andinteraction strategy. Based on these observations, along with qualitative feedback from a user walkthrough session, we identify implications and recommend features for immersive multiview map systems. Our main findings are that participants tend to prefer and arrange multiview maps in a spherical cap layout around them and that they often rearrange the views during tasks.

Freehand gesture interaction has long been proposed as a `natural' input method for Augmented Reality (AR) applications, yet has been little explored for intensive applications like multiscale navigation. In multiscale navigation, such as digital map navigation, pan and zoom are the predominant interactions. A position-based input mapping (e.g. grabbing metaphor) is intuitive for such interactions, but is prone to arm fatigue. This work focuses on improving digital map navigation in AR with mid-air hand gestures, using a horizontal intangible map display. First, we conducted a user study to explore the effects of handedness (unimanual and bimanual) and input mapping (position-based and rate-based). From these findings we designed DiveZoom and TerraceZoom, two novel hybrid techniques that smoothly transition between position- and rate-based mappings. A second user study evaluated these designs. Our results indicate that the introduced input-mapping transitions can reduce perceived arm fatigue with limited impact on performance.