We characterize 16 challenges faced by those investigating and developing remote and synchronous collaborative experiences around visualization. Our work reflects the perspectives and prior research efforts of an international group of 29 experts from across human-computer interaction and visualization sub-communities. The challenges are anchored around five collaborative activities that exhibit a centrality of visualization and multimodal communication. These activities include exploratory data analysis, creative ideation, visualization-rich presentations, joint decision making grounded in data, and real-time data monitoring. The challenges also reflect the changing dynamics of these activities in the face of recent advances in extended reality (XR) and artificial intelligence (AI). As an organizing scheme for future research at the intersection of visualization and computer-supported cooperative work, we align the challenges with a sequence of four sets of research and development activities: technological choices, social factors, AI assistance, and evaluation.

Abstract Evidence continues to accrue around the difficulties people have understanding new and complex visualizations, which in turn provides continued incentive to explore additional methods of supporting visualization viewers. Through leveraging viewers' spontaneous visualization sensemaking activities, we introduce a Serendipitous Explanation Approach (SEA). A significant part of SEA's contribution is making active use of a viewer's spontaneous, exploration interactions to offer in situ explanations. SEA adds semantic and structural explanations, making use of visual transformations, and additional representations of visualization elements themselves to communicate meaning through highlights, reconfigurations, and in‐situ annotations. We designed and studied VisTips as an instantiation of SEA. Our study demonstrates the prevalence of spontaneous interaction and appreciation of this approach. Among the explanation types, visual transformations stood out as especially impactful. Our findings also offer practical insights for future use of the ideas in SEA, opening possibilities for seamlessly integrating explanatory visuals that support viewers' natural visualization sensemaking.

Abstract AI4VIS EthiCards are a card‐based approach designed to facilitate ethical exploration in the growing research of artificial intelligence (AI) for visualization (AI4VIS). The continuously increasing integration of AI and data visualization offers many benefits yet inevitably raises ethical concerns. AI4VIS applications, characterized by their interdisciplinary and multifaceted nature, necessitate that researchers, designers, and practitioners develop ethical awareness and critically reflect on their responsibilities within this domain. The AI4VIS EthiCards, organized into six types, i.e., Goal, AI4VIS Task, Technology, Ethical Principle, People‐In‐Focus , and Challenge , serve as a framework for discussion and ethical reflection. This card deck is designed for students, educators, and practitioners working with AI and visualization, and can be used as a flexible teaching framework, rapid reference, or self‐check tool in small‐group design and reflection activities. We refined the deck through five workshops and observed three main outcomes: participants' speculative yet feasible concepts revealed AI4VIS as a high‐potential design space; the deck supported more nuanced ethical awareness; and it functioned as a multi‐perspective scaffold and shared vocabulary that enabled people from different backgrounds to reason together across technological, user‐centred, and value‐oriented dimensions.

Unlike digital visualization, physicalization design introduces structural and material uncertainties, which require immediate feedback and often rapid iteration. This makes physicalization design a speculative, labor-intensive, and expertise-dependent activity. While speculative reasoning can be central to physicalization, authoring tools remain scarce and there is a lack of computational support that can help in anticipating physicalization outcomes. We explore how feedforward mechanisms (predictive features) might help physicalization designers anticipate post-fabrication qualities like tactile feel and expandability before fabrication, by iteratively developing and studying DataCuts, a physicalization authoring tool for designing Kirigami-based data physicalizations. Our study findings show that DataCuts’ simple feedforward functionalities can inform design decisions, shape people’s understanding of physical properties and encourage tactile representation over conventional mappings. Building on these results, we discuss implications for designing data physicalization support tools that integrate feedforward.

Enhancing visualization comprehension has been approached through multiple research streams, with significant contributions from areas such as visualization literacy, sensemaking, insight, and graphical perception. While each of these streams independently enhances specific aspects of viewers understanding, they have tended to remain distinct. In this paper, first, we describe the distinct streams of visualization comprehension research and elucidate the interplay between them. Then, we provide design considerations that emerge from these streams. We also outline research opportunities within and at the intersections of these streams. By exploring these connections, we aim to provide a broader perspective on how different approaches to visualization comprehension can inform one another and enhance user engagement with visual data.

International audience

This paper investigates how people use physical space, free from digital constraints, to organize thoughts and ideas. Such spatial arrangements commonly support sensemaking, idea generation, and data understanding. We collected over 300 publicly shared images capturing these activities collected from real-world contexts. Our visual analysis identifies a small set of recurring spatial patterns such as clusters, grids as well as the techniques people use to build and adapt them, such as color coding, directional lines, and selective rule-following. We discuss how these practices can inform the design of more expressive and adaptable digital spatially-aware tools that better support the diverse ways people think with space.

Through co-design with patients undergoing hemodialysis and their healthcare professionals, we worked towards discovering how to create a personalised, welcoming, yet quick and accurate method for medical instruction communication. Exploring possibilities of meeting the widely differing goals of patients and their healthcare professionals led to designing a personalise-able method for creating comics. Through ongoing discussions during the comic creation process, we explored variations in comic styles and personalisation factors such as choosing and modifying the appearance of the comic personalities, the settings, the central topics, and word usage to create the comics. Interest in using the approach that supports the creation of medical comics was high among patients and healthcare professionals. Rich feedback was obtained about information to be included and future direction for such medical comic creation support. We reflect on lessons learned during co-design with healthcare givers and patients.

We designed, developed, and studied a visualization, WPHPVis, to support exploration of the Women’s Print History Project (WPHP) data. WPHP are manually-collecting a bibliography that spans the years 1700 to 1836 recording information about books in which women have been involved through a number of roles including as authors, editors, translators, publishers, printers and booksellers. By working directly with WPHP experts to focus on their understanding, and their research practices and needs, we co-designed WPHPVis using interactive construction of network links to support exploration of their data. Through our qualitative study with both experts and non-experts, we learned about how the tool supported the WPHP experts’ research practices as well as about how to improve overall interactive experience. We conclude by discussing the importance of representing missing data, the advantages of striking a balance between visualization structure and explorability, and the opportunities enabled by co-design with domain experts.

This paper is a call to action for research and discussion on data visualization education. As visualization evolves and spreads through our professional and personal lives, we need to understand how to support and empower a broad and diverse community of learners in visualization. Data Visualization is a diverse and dynamic discipline that combines knowledge from different fields, is tailored to suit diverse audiences and contexts, and frequently incorporates tacit knowledge. This complex nature leads to a series of interrelated challenges for data visualization education. Driven by a lack of consolidated knowledge, overview, and orientation for visualization education, the 21 authors of this paper-educators and researchers in data visualization-identify and describe 19 challenges informed by our collective practical experience. We organize these challenges around seven themes People, Goals & Assessment, Environment, Motivation, Methods, Materials, and Change. Across these themes, we formulate 43 research questions to address these challenges. As part of our call to action, we then conclude with 5 cross-cutting opportunities and respective action items: embrace DIVERSITY+INCLUSION, build COMMUNITIES, conduct RESEARCH, act AGILE, and relish RESPONSIBILITY. We aim to inspire researchers, educators and learners to drive visualization education forward and discuss why, how, who and where we educate, as we learn to use visualization to address challenges across many scales and many domains in a rapidly changing world: viseducationchallenges.github.io.

Despite an abundance of open data initiatives aimed to inform and empower "general" audiences, we still know little about the ways people outside of traditional data analysis communities experience and engage with public data and visualizations. To investigate this gap, we present results from an in-depth qualitative interview study with 19 participants from diverse ethnic, occupational, and demographic backgrounds. Our findings characterize a set of lived experiences with open data and visualizations in the domain of energy consumption, production, and transmission. This work exposes information receptivity - an individual's transient state of willingness or openness to receive information -as a blind spot for the data visualization community, complementary to but distinct from previous notions of data visualization literacy and engagement. We observed four clusters of receptivity responses to data- and visualization-based rhetoric: Information-Avoidant, Data-Cautious, Data-Enthusiastic, and Domain-Grounded. Based on our findings, we highlight research opportunities for the visualization community. This exploratory work identifies the existence of diverse receptivity responses, highlighting the need to consider audiences with varying levels of openness to new information. Our findings also suggest new approaches for improving the accessibility and inclusivity of open data and visualization initiatives targeted at broad audiences. A free copy of this paper and all supplemental materials are available at https://OSF.IO/MPQ32.

While the visualization community is increasingly aware that people often find visualizations difficult to understand, there is less information about what we need to do to create comprehensible visualizations. To help visualization creators and designers improve their visualizations, we need to better understand what kind of support people are looking for in their sensemaking process. Empirical studies are needed to tease apart the details of what makes the process of understanding difficult for visualization viewers. We conducted a qualitative study with 14 participants, observing them as they described how they were trying to make sense of 20 information visualizations. We identified the challenges participants faced throughout their sensemaking process and the strategies they employed to help themselves in overcoming the challenges. Our findings show how details and nuances within visualizations can impact comprehensibility and offer research suggestions to help us move toward more understandable visualizations.

The growing need for programming and computational skills has led to a demand for teaching approaches that can appeal to a broader audience. We explore the design and creation of tangible objects and interactions to make introductory programming concepts more engaging and less tedious. We introduce TangiBooks, a platform that uses paper-based tangibles with embedded electronics and augments paper with sensory interactions like visuals, sounds, haptics, and kinesthetics to reinforce learning. The platform is implemented as proof-of-concept and offers four self-contained lessons on key concepts such as algorithms, variables, conditionals, and loops. Results from our observational study (12 adult learners, 6 instructors) showed that participants found TangiBooks to be playful, appealing to their senses, and valuable for sparking curiosity, with potential pedagogical benefits for promoting reflection among learners. TangiBooks has implications for HCI researchers in furthering the design space of paper-based tangibles in the learning domain and empowering instructors to innovate and personalize lessons.

We present KiriPhys, a new type of data physicalization based on kirigami, a traditional Japanese art form that uses paper-cutting. Within the kirigami possibilities, we investigate how different aspects of cutting patterns offer opportunities for mapping data to both independent and dependent physical variables. As a first step towards understanding the data physicalization opportunities in KiriPhys, we conducted a qualitative study in which 12 participants interacted with four KiriPhys examples. Our observations of how people interact with, understand, and respond to KiriPhys suggest that KiriPhys: 1) provides new opportunities for interactive, layered data exploration, 2) introduces elastic expansion as a new sensation that can reveal data, and 3) offers data mapping possibilities while providing a pleasurable experience that stimulates curiosity and engagement.

Persistently, data has been part of our lives through the ages. Our use of data is nearly always private, often small, but has continually formed a part of how we live our everyday lives. Very often it is stored, saved, and preserved as part of our arts and crafts through the ages. It is important that we do not let the current ‘big data’ revolution with all its emphasis on bigness and power, alienate us from our deep connection with data. It is important that we share the potentially empowering aspects of the use of small, situated, and embedded data. I will discuss this in relation to my continued research towards promoting data comprehension by creating appropriate interactive technologies that can help people negotiate the everyday transformation of data into understanding. Specifically, I will talk about my research into extending the available visual representations, using interaction to expand the potential of existing visualizations, and into broadening the potential of information visualization by investigating engagement with new audiences. Just as data has in the past, it still has the potential to enrich our daily lives. Let’s not get dis-inherited!

We explore how the lens of fictional superpowers can help characterize how visualizations empower people and provide inspiration for new visualization systems. Researchers and practitioners often tout visualizations' ability to "make the invisible visible" and to "enhance cognitive abilities." Meanwhile superhero comics and other modern fiction often depict characters with similarly fantastic abilities that allow them to see and interpret the world in ways that transcend traditional human perception. We investigate the intersection of these domains, and show how the language of superpowers can be used to characterize existing visualization systems and suggest opportunities for new and empowering ones. We introduce two frameworks: The first characterizes seven underlying mechanisms that form the basis for a variety of visual superpowers portrayed in fiction. The second identifies seven ways in which visualization tools and interfaces can instill a sense of empowerment in the people who use them. Building on these observations, we illustrate a diverse set of "visualization superpowers" and highlight opportunities for the visualization community to create new systems and interactions that empower new experiences with data Material and illustrations are available under CC-BY 4.0 at osf.io/8yhfz.

We present Activity River, a personal visualization tool which enables individuals to plan, log, and reflect on their self-defined activities. We are interested in supporting this type of reflective practice as prior work has shown that reflection can help people plan and manage their time effectively. Hence, we designed Activity River based on five design goals (visualize historical and contextual data, facilitate comparison of goals and achievements, engage viewers with delightful visuals, support authorship, and enable flexible planning and logging) which we distilled from the Information Visualization and Human-Computer Interaction literature. To explore our approach's strengths and limitations, we conducted a qualitative study of Activity River using a role-playing method. Through this qualitative exploration, we illustrate how our participants envisioned using our visualization to perform dynamic and continuous reflection on their activities. We observed that they were able to assess their progress towards their plans and adapt to unforeseen circumstances using our tool.

We were approached by a group of healthcare providers who are involved in the care of chronic patients looking for potential technologies to facilitate the process of reviewing patient-generated data during clinical visits. Aiming at understanding the healthcare providers' attitudes towards reviewing patient-generated data, we (1) conducted a focus group with a mixed group of healthcare providers. Next, to gain the patients' perspectives, we (2) interviewed eight chronic patients, collected a sample of their data and designed a series of visualizations representing patient data we collected. Last, we (3) sought feedback on the visualization designs from healthcare providers who requested this exploration. We found four factors shaping patient-generated data: data & context, patient's motivation, patient's time commitment, and patient's support circle. Informed by the results of our studies, we discussed the importance of designing patient-generated visualizations for individuals by considering both patient and healthcare provider rather than designing with the purpose of generalization and provided guidelines for designing future patient-generated data visualizations.

While previous work exists on how to conduct and disseminate insights from problem-driven visualization projects and design studies, the literature does not address how to accomplish these goals in transdisciplinary teams in ways that advance all disciplines involved. In this paper we introduce and define a new methodological paradigm we call design by immersion, which provides an alternative perspective on problem-driven visualization work. Design by immersion embeds transdisciplinary experiences at the center of the visualization process by having visualization researchers participate in the work of the target domain (or domain experts participate in visualization research). Based on our own combined experiences of working on cross-disciplinary, problem-driven visualization projects, we present six case studies that expose the opportunities that design by immersion enables, including (1) exploring new domain-inspired visualization design spaces, (2) enriching domain understanding through personal experiences, and (3) building strong transdisciplinary relationships. Furthermore, we illustrate how the process of design by immersion opens up a diverse set of design activities that can be combined in different ways depending on the type of collaboration, project, and goals. Finally, we discuss the challenges and potential pitfalls of design by immersion.

Complex data visualization design projects often entail collaboration between people with different visualization-related skills. For example, many teams include both designers who create new visualization designs and developers who implement the resulting visualization software. We identify gaps between data characterization tools, visualization design tools, and development platforms that pose challenges for designer-developer teams working to create new data visualizations. While it is common for commercial interaction design tools to support collaboration between designers and developers, creating data visualizations poses several unique challenges that are not supported by current tools. In particular, visualization designers must characterize and build an understanding of the underlying data, then specify layouts, data encodings, and other data-driven parameters that will be robust across many different data values. In larger teams, designers must also clearly communicate these mappings and their dependencies to developers, clients, and other collaborators. We report observations and reflections from five large multidisciplinary visualization design projects and highlight six data-specific visualization challenges for design specification and handoff. These challenges include adapting to changing data, anticipating edge cases in data, understanding technical challenges, articulating data-dependent interactions, communicating data mappings, and preserving the integrity of data mappings across iterations. Based on these observations, we identify opportunities for future tools for prototyping, testing, and communicating data-driven designs, which might contribute to more successful and collaborative data visualization design.

Astral is a prototyping tool for authoring mobile and smart object interactive behaviours. It mirrors selected display contents of desktop applications onto mobile devices (smartphones and smartwatches), and streams/remaps mobile sensor data to desktop input events (mouse or keyboard) to manipulate selected desktop contents. This allows designers to use familiar desktop applications (e.g. PowerPoint, AfterEffects) to prototype rich interactive behaviours. Astral combines and integrates display mirroring, sensor streaming and input remapping, where designers can exploit familiar desktop applications to prototype, explore and fine-tune dynamic interactive behaviours. With Astral, designers can visually author rules to test real-time behaviours while interactions take place, as well as after the interaction has occurred. We demonstrate Astral's applicability, workflow and expressiveness within the interaction design process through both new examples and replication of prior approaches that illustrate how various familiar desktop applications are leveraged and repurposed.

We investigate engaging a computer science conference audience in sketching responses to the event as it occurs. In particular, we explore the response to inviting those present to engage in what is essentially an off-line, co-located, attendee-sourcing experience. Sketchnoting is a popular practice for documenting events, but these sketched records can be limited in scope at multi-track conferences, and paid professionals can be unaffordable at smaller events. Our challenges included: working with an audience with little or no experience of sketching or working with imagery; who were unaware of the possible benefits; and whose attendee engagement was variable - with individuals often working on laptops rather than actively listening during sessions. In order encourage engagement we hosted a pre-conference workshop, developed a conference-specific set of visual icons, and created prompt materials. This resulted in a remarkable visual record of the event, and also an increase in active listening and engagement.

Providing data visualization authoring tools for the general public remains an ongoing challenge. Inspired by block-printing, we explore how visualization stamps as a physical visualization authoring tool could leverage both visual freedom and ease of repetition. We conducted a workshop with two groups---visualization experts and non-experts---where participants authored visualizations on paper using hand-carved stamps made from potatoes and sponges. The low-fidelity medium freed participants to test new stamp patterns and accept mistakes. From the created visualizations, we observed several unique traits and uses of block-printing tools for visualization authoring, including: modularity of patterns, annotation guides, creation of multiple patterns from one stamp, and various techniques to apply data onto paper. We discuss the issues around expressivity and effectiveness of block-printed stamps in visualization authoring, and identify implications for the design and assembly of primitives in potential visualization stamp kits, as well as applications for future use in non-digital environments.

We investigate how people discover the functionality of an interactive visualization that was designed for the general public. While interactive visualizations are increasingly available for public use, we still know little about how the general public discovers what they can do with these visualizations and what interactions are available. Developing a better understanding of this discovery process can help inform the design of visualizations for the general public, which in turn can help make data more accessible. To unpack this problem, we conducted a lab study in which participants were free to use their own methods to discover the functionality of a connected set of interactive visualizations of public energy data. We collected eye movement data and interaction logs as well as video and audio recordings. By analyzing this combined data, we extract exploration strategies that the participants employed to discover the functionality in these interactive visualizations. These exploration strategies illuminate possible design directions for improving the discoverability of a visualization's functionality.

The 2018 Visualization Career Award goes to Sheelagh Carpendale for her work in interactive data exploration, in visualization in novel contexts such as wall and tabletop display, in rigorous qualitative evaluation methods, in bringing aesthetic considerations to the research community, and for her contributions in a wide range of application domains, including medicine, digital humanities, geography, the environment, personal data, and emergency management. The IEEE Visualization & Graphics Technical Committee (VGTC) is pleased to award Sheelagh Carpendale the 2018 Visualization Career Award.

We present decal-lenses, a new interaction technique that extends the concept of magic lenses to augment and manage multivariate visualizations on arbitrary surfaces. Our object-space lenses follow the surface geometry and allow the user to change the point of view during data exploration while maintaining a spatial reference to positions where one or more lenses were placed. Each lens delimits specific regions of the surface where one or more attributes can be selected or combined. Similar to 2D lenses, the user interacts with our lenses in real-time, switching between different attributes within the lens context. The user can also visualize the surface data representations from the point of view of each lens by using local cameras. To place lenses on surfaces of intricate geometry, such as the human brain, we introduce the concept of support surfaces for designing interaction techniques. Support surfaces provide a way to place and interact with the lenses while avoiding holes and occluded regions during data exploration. We further extend decal-lenses to arbitrary regions using brushing and lassoing operations. We discuss the applicability of our technique and present several examples where our lenses can be useful to create a customized exploration of multivariate data on surfaces.

Self-reflection is a central goal of personal informatics systems, and constructing visualizations from physical tokens has been found to help people reflect on data. However, so far, constructive physicalization has only been studied in lab environments with provided datasets. Our qualitative study investigates the construction of personal physicalizations in people's domestic environments over 2-4 weeks. It contributes an understanding of (1) the process of creating personal physicalizations, (2) the types of personal insights facilitated, (3) the integration of self-reflection in the physicalization process, and (4) its benefits and challenges for self-reflection. We found that in constructive personal physicalization, data collection, construction and self-reflections are deeply intertwined. This extends previous models of visualization creation and data-driven self-reflection. We outline how benefits such as reflection through manual construction, personalization, and presence in everyday life can be transferred to a wider set of digital and physical systems.

Abstract We introduce an approach for explicitly revealing changes between versions of a visualization workbook to support version comparison tasks. Visualization authors may need to understand version changes for a variety of reasons, analogous to document editing. An author who has been away for a while may need to catch up on the changes made by their co‐author, or a person responsible for formatting compliance may need to check formatting changes that occurred since the last time they reviewed the work. We introduce ChangeCatcher, a prototype tool to help people find and understand changes in a visualization workbook, specifically, a Tableau workbook. Our design is based on interviews we conducted with experts to investigate user needs and practices around version comparison. ChangeCatcher provides an overview of changes across six categories, and employs a multi‐level details‐on‐demand approach to progressively reveal details. Our qualitative study showed that ChangeCatcher's methods for explicitly revealing and categorizing version changes were helpful in version comparison tasks.

Abstract In this report, we organize and reflect on recent advances and challenges in the field of sports data visualization. The exponentially‐growing body of visualization research based on sports data is a prime indication of the importance and timeliness of this report. Sports data visualization research encompasses the breadth of visualization tasks and goals: exploring the design of new visualization techniques; adapting existing visualizations to a novel domain; and conducting design studies and evaluations in close collaboration with experts, including practitioners, enthusiasts, and journalists. Frequently this research has impact beyond sports in both academia and in industry because it is i) grounded in realistic, highly heterogeneous data, ii) applied to real‐world problems, and iii) designed in close collaboration with domain experts. In this report, we analyze current research contributions through the lens of three categories of sports data: box score data (data containing statistical summaries of a sport event such as a game), tracking data (data about in‐game actions and trajectories), and meta‐data (data about the sport and its participants but not necessarily a given game). We conclude this report with a high‐level discussion of sports visualization research informed by our analysis—identifying critical research gaps and valuable opportunities for the visualization community. More information is available at the STAR's website: https://sportsdataviz.github.io/ .

We extend the popular brushing and linking technique by incorporating personal agency in the interaction. We map existing research related to brushing and linking into a design space that deconstructs the interaction technique into three components: source (what is being brushed), link (the expression of relationship between source and target), and target (what is revealed as related to the source). Using this design space, we created MyBrush, a unified interface that offers personal agency over brushing and linking by giving people the flexibility to configure the source, link, and target of multiple brushes. The results of three focus groups demonstrate that people with different backgrounds leveraged personal agency in different ways, including performing complex tasks and showing links explicitly. We reflect on these results, paving the way for future research on the role of personal agency in information visualization.

We empirically evaluate the extent to which people perceive non-constant time and speed encoded on 2D paths. In our graphical perception study, we evaluate nine encodings from the literature for both straight and curved paths. Visualizing time and speed information is a challenge when the x and y axes already encode other data dimensions, for example when plotting a trip on a map. This is particularly true in disciplines such as time-geography and movement analytics that often require visualizing spatio-temporal trajectories. A common approach is to use 2D+time trajectories, which are 2D paths for which time is an additional dimension. However, there are currently no guidelines regarding how to represent time and speed on such paths. Our study results provide InfoVis designers with clear guidance regarding which encodings to use and which ones to avoid; in particular, we suggest using color value to encode speed and segment length to encode time whenever possible.

We investigate whether the notion of active reading for text might be usefully applied to visualizations. Through a qualitative study we explored whether people apply observable active reading techniques when reading paper-based node-link visualizations. Participants used a range of physical actions while reading, and from these we synthesized an initial set of active reading techniques for visualizations. To learn more about the potential impact such techniques may have on visualization reading, we implemented support for one type of physical action from our observations (making freeform marks) in an interactive node-link visualization. Results from our quantitative study of this implementation show that interactive support for active reading techniques can improve the accuracy of performing low-level visualization tasks. Together, our studies suggest that the active reading space is ripe for research exploration within visualization and can lead to new interactions that make for a more flexible and effective visualization reading experience.

Evaluation is increasingly recognized as an essential component of HCI research. However, evaluation itself is a changing research area. In particular, the many variations of qualitative research are emerging as important empirical methods. This half-day tutorial is designed for beginning to intermediate audiences. We will focus on the basic methods for analyzing qualitative data using a mixture of talks and hands-on activities. In particular we will consider closed and open coding as well as clustering and categorizing coded data. After completing this tutorial, attendees will have a richer understanding of the benefits and challenges of qualitative empirical research and, more specifically, how to analyze qualitative data.

We explore the presentation technique of visual abstraction as a form of mediation to manage content generated by the public in order to maintain a respectful discourse. We identify technological and social mediation as two dimensions within the space of content mediation, and discuss different solutions based on related work in public interactive displays and art installations. We further discuss a novel approach to technological mediation by describing our interactive artwork Objective Meaning - an installation that invites the audience to express themselves through anonymous text messages. The design of this system mediates discourse by visually abstracting the presentation of messages on a display by breaking messages apart into decontextualized words. We briefly discuss the public response during a one-month deployment of the installation in a library setting.

In this paper, we present Torrent, for Flutes and Water. Torrent is an embodied electroacoustic music composition written to commemorate a catastrophic local flood and the spirit of the citizens who united to overcome it. To create this music, we designed and built an interactive computer system to make audible and physical that which is usually hidden but ever-present in music-making: the musicians' muscle tension as they perform, think about, and feel their music. The Torrent system musifies and physicalizes the flutists' muscle tension as live water sounds and movement that accompany the musicians as they perform. Semi-structured interviews and surveys were conducted to under-stand the experiences of the performers and audience during one performance. The use of embodiment, as integral to the music itself, aspires to emphasize means and end, body and mind, effort and achievement in the struggle of people unit-ed against the elements.

Abstract We present thegeneralized space‐time cube, a descriptive model for visualizations of temporal data. Visualizations are described as operations on the cube, which transform the cube's 3D shape into readable 2D visualizations. Operations include extracting subparts of the cube, flattening it across space or time or transforming the cubes geometry and content. We introduce a taxonomy of elementary space‐time cube operations and explain how these operations can be combined and parameterized. The generalized space‐time cube has two properties: (1) it is purely conceptual without the need to be implemented, and (2) it applies to all datasets that can be represented in two dimensions plus time (e.g. geo‐spatial, videos, networks, multivariate data). The proper choice of space‐time cube operations depends on many factors, for example, density or sparsity of a cube. Hence, we propose a characterization of structures within space‐time cubes, which allows us to discuss strengths and limitations of operations. We finally review interactive systems that support multiple operations, allowing a user to customize his view on the data. With this framework, we hope to facilitate the description, criticism and comparison of temporal data visualizations, as well as encourage the exploration of new techniques and systems. This paper is an extension of Bachet al.'s (2014) work.

Heterogeneous multi-dimensional data are now sufficiently common that they can be referred to as ubiquitous. The most frequent approach to visualizing these data has been to propose new visualizations for representing these data. These new solutions are often inventive but tend to be unfamiliar. We take a different approach. We explore the possibility of extending well-known and familiar visualizations through including Heterogeneous Embedded Data Attributes (HEDA) in order to make familiar visualizations more powerful. We demonstrate how HEDA is a generic, interactive visualization component that can extend common visualization techniques while respecting the structure of the familiar layout. HEDA is a tabular visualization building block that enables individuals to visually observe, explore, and query their familiar visualizations through manipulation of embedded multivariate data. We describe the design space of HEDA by exploring its application to familiar visualizations in the D3 gallery. We characterize these familiar visualizations by the extent to which HEDA can facilitate data queries based on attribute reordering.

An increasing share of our daily interactions with others is mediated through mobile communication technologies. People communicate via text, emoticons, emojis and rich media such as video. We explore the design of Heartefacts, short video clips composed of highlights determined by heart rate changes while watching videos. Our survey investigated video sharing behaviour, and our feasibility study examined the possibility of detecting highlights in videos by monitoring people's heart rates measured with off-the-shelf wrist-worn sensors. Our results show that people do indeed have measurable responses with respect to their heartbeat patterns to six different emotions elicited by video clips. We compare video highlights verbally identified by our participants to physiological highlights as indicated by their heart rate data and also discuss and compare the automatically generated Heartefacts with video highlights created by an expert in video art. We close with design considerations for Heartefacts in mobile technology.

Motivation is a key factor for introducing and maintaining healthy changes in behaviour. However, typical visualization methods (e.g., bar-, pie-, and line charts) hardly motivate individuals. We investigate how a plant---a living visualization---whose health relies on the plant owner's level of activity, can engage people in tracking and self-reflecting on their fitness data. To address this question, we designed, implemented, and studied Go & Grow, a living plant that receives water proportionally to its owner's activity. Our six-week qualitative study with ten participants suggests that living visualizations have qualities that their digital counterparts do not have. This includes people feeling: emotionally connected to their plant; sentiments such as pride and guilt; and responsibility towards their plant. Based on this study, we introduce the Goal Motivation Model, a model considering the diversity of individuals, thus supporting and encouraging a diversity of strategies for accomplishing goals.

We introduce Flexible Trees, a sketch-based layout adjustment technique. Although numerous tree layout algorithms exist, these algorithms are usually bound to fit within standard shapes such as rectangles, circles and triangles. In order to provide the possibility of interactively customizing a tree layout, we offer a free-form sketch-based interaction through which one can re-define the boundary constraints for the tree layouts by combining ray-line intersection and line segment intersection. Flexible Trees offer topology preserving adjustments; can be used with a variety of tree layouts; and offer a simple way of authoring tree layouts for infographic purposes.

In this paper, we explore graph comics as a medium to communicate changes in dynamic networks. While previous re- search has focused on visualizing dynamic networks for data exploration, we want to see if we can take advantage of the visual expressiveness and familiarity of comics to present and explain temporal changes in networks to an audience. To understand the potential of comics as a storytelling medium, we first created a variety of comics during a 3 month structured design process, involving domain experts from public education and neuroscience. This process led to the definition of 8 design factors for creating graph comics and propose design solutions for each. Results from a qualitative study suggest that a general audience is quickly able understand complex temporal changes through graph comics, provided with minimal textual annotations and no training.

Stacked graphs are a visualization technique popular in casual scenarios for representing multiple time-series. Variations of stacked graphs have been focused on reducing the distortion of individual streams because foundational perceptual studies suggest that variably curved slopes may make it difficult to accurately read and compare values. We contribute to this discussion by formally comparing the relative readability of basic stacked area charts, ThemeRivers, streamgraphs and our own interactive technique for straightening baselines of individual streams in a ThemeRiver. We used both real-world and randomly generated datasets and covered tasks at the elementary, intermediate and overall information levels. Results indicate that the decreased distortion of the newer techniques does appear to improve their readability, with streamgraphs performing best for value comparison tasks. We also found that when a variety of tasks is expected to be performed, using the interactive version of the themeriver leads to more correctness at the cost of being slower for value comparison tasks.

We propose to conduct a workshop on the topic of Immersive Analytics: a new multidisciplinary initiative to explore future interaction technologies for data analytics. Immersive Analytics aims to bring together researchers in Information Visualisation, Visual Analytics, Virtual and Augmented Reality and Natural User Interfaces. http://immersiveanalytics.net

Abstract We provide afresh look at the use and prevalence of emphasis effects in Infovis. Through a survey of existing emphasis frameworks, we extract a set‐based approach that uses visual prominence to link visually and algorithmically diverse emphasis effects. Visual prominence provides a basis for describing, comparing and generating emphasis effects when combined with a set of general features of emphasis effects. Therefore, we use visual prominence and these general features to construct a new mathematical Framework for Information Visualization Emphasis, FIVE. The concepts we introduce to describe FIVE unite the emphasis literature and point to several new research directions for emphasis in information visualization.

Abstract We present GSUVis, a visualization tool designed to provide better understanding of location‐based social network (LBSN) data. LBSN data is one of the most important sources of information for transportation, marketing, health, and public safety. LBSN data consumers are interested in accessing and analysing data that is as complete and as accurate as possible. However, LBSN data contains sensitive information about individuals. Consequently, data anonymization is of critical importance if this data is to be made available to consumers. However, anonymization commonly reduces the utility of information available. Working with privacy experts, we designed GSUVis a visual analytic tool to help experts better understand the effects of anonymization techniques on LBSN data utility. One of GSUVis's primary goals is to make it possible for people to use LBSN data, without requiring them to gain deep knowledge about data anonymization. To inform the design of GSUVis, we interviewed privacy experts, and collected their tasks and system requirements. Based on this understanding, we designed and implemented GSUVis. It applies two anonymization algorithms for social and location trajectory data to a real‐world LBSN dataset and visualizes the data both before and after anonymization. Through feedback from domain experts, we reflect on the effectiveness of GSUVis and the impact of anonymization using visualization.

Abstract Providing tools that make visualization authoring accessible to visualization non‐experts is a major research challenge. Currently the most common approach to generating a visualization is to use software that quickly and automatically produces visualizations based on templates. However, it has recently been suggested that constructing a visualization with tangible tiles may be a more accessible method, especially for people without visualization expertise. There is still much to be learned about the differences between these two visualization authoring practices. To better understand how people author visualizations in these two conditions, we ran a qualitative study comparing the use of software to the use of tangible tiles, for the creation of bar charts. Close observation of authoring activities showed how each of the following varied according to the tool used: 1) sequences of action; 2) distribution of time spent on different aspects of the InfoVis pipeline; 3) pipeline task separation; and 4) freedom to manipulate visual variables. From these observations, we discuss the implications of the variations in activity sequences, noting tool design considerations and pointing to future research questions.

Displaying 3D objects on horizontal displays can cause problems in the way that the virtual scene is presented on the 2D surface; inappropriate choices in how 3D is represented can lead to distorted images and incorrect object interpretations. We present four experiments that test 3D perception. We varied projection geometry in three ways: type of projection (perspective/parallel), separation between the observer's point of view and the projection's center (discrepancy), and the presence of motion parallax (with/without parallax). Projection geometry had strong effects different for each task. Reducing discrepancy is desirable for orientation judgments, but not for object recognition or internal angle judgments. Using a fixed center of projection above the table reduces error and improves accuracy in most tasks. The results have far-reaching implications for the design of 3D views on tables, in particular, for multi-user applications where projections that appear correct for one person will not be perceived correctly by another.

We present an efficient technique for topology-preserving map deformation and apply it to the visualization of dissimilarity data in a geographic context. Map deformation techniques such as value-by-area cartograms are well studied. However, using deformation to highlight (dis)similarity between locations on a map in terms of their underlying data attributes is novel. We also identify an alternative way to represent dissimilarities on a map through the use of visual overlays. These overlays are complementary to deformation techniques and enable us to assess the quality of the deformation as well as to explore the design space of blending the two methods. Finally, we demonstrate how these techniques can be useful in several-quite different-applied contexts: travel-time visualization, social demographics research and understanding energy flowing in a wide-area power-grid.

We present TimeSpan, an exploratory visualization tool designed to gain a better understanding of the temporal aspects of the stroke treatment process. Working with stroke experts, we seek to provide a tool to help improve outcomes for stroke victims. Time is of critical importance in the treatment of acute ischemic stroke patients. Every minute that the artery stays blocked, an estimated 1.9 million neurons and 12 km of myelinated axons are destroyed. Consequently, there is a critical need for efficiency of stroke treatment processes. Optimizing time to treatment requires a deep understanding of interval times. Stroke health care professionals must analyze the impact of procedures, events, and patient attributes on time-ultimately, to save lives and improve quality of life after stroke. First, we interviewed eight domain experts, and closely collaborated with two of them to inform the design of TimeSpan. We classify the analytical tasks which a visualization tool should support and extract design goals from the interviews and field observations. Based on these tasks and the understanding gained from the collaboration, we designed TimeSpan, a web-based tool for exploring multi-dimensional and temporal stroke data. We describe how TimeSpan incorporates factors from stacked bar graphs, line charts, histograms, and a matrix visualization to create an interactive hybrid view of temporal data. From feedback collected from domain experts in a focus group session, we reflect on the lessons we learned from abstracting the tasks and iteratively designing TimeSpan.

In this paper we discuss the creation of visual mementos as a new application area for visualization. We define visual mementos as visualizations of personally relevant data for the purpose of reminiscing, and sharing of life experiences. Today more people collect digital information about their life than ever before. The shift from physical to digital archives poses new challenges and opportunities for self-reflection and self-representation. Drawing on research on autobiographical memory and on the role of artifacts in reminiscing, we identified design challenges for visual mementos: mapping data to evoke familiarity, expressing subjectivity, and obscuring sensitive details for sharing. Visual mementos can make use of the known strengths of visualization in revealing patterns to show the familiar instead of the unexpected, and extend representational mappings beyond the objective to include the more subjective. To understand whether people's subjective views on their past can be reflected in a visual representation, we developed, deployed and studied a technology probe that exemplifies our concept of visual mementos. Our results show how reminiscing has been supported and reveal promising new directions for self-reflection and sharing through visual mementos of personal experiences.

We present Electronic & Radially-focused Instantaneous Coordinate Animations (ERICAs) as a visualization approach to represent the time evolution of the electronic structure data and nuclear coordinates resulting from ab initio Molecular Dynamics (AIMD) simulations. We developed ERICAs in order to enable chemists to analyze AIMD simulations of the interactions between two hydroxyl radicals in water. Consequently, we illustrate ERICAs using these simulations, and discuss how ERICAs can be generalized to other AIMD simulations. By using ERICAs, chemists have gained new insights into hydroxyl radical chemistry.

In this work, we advance research efforts in combining the casual sketching approach of whiteboards with the machine's computing power. We present SketchInsight, a system that applies the familiar and collaborative features of a whiteboard interface to the accurate data exploration capabilities of interactive visualizations. SketchInsight enables data analysis with more fluid interaction, allowing people to visually explore their data by drawing simple charts and directly manipulating them. In addition, we report results from a qualitative study conducted to evaluate user experience in exploring data with SketchInsight, expanding our understanding on how people use a pen- and touch-enabled digital whiteboard for data exploration. We also discuss the challenges in building a working system that supports data analytic capabilities with pen and touch interaction and freeform annotation.

When searching through collections of books or written texts, the efficient yet limiting query paradigm is still the most dominant entry point. Previous work characterizes search processes in various contexts and describes them as integral and closely related to creative endeavours. We revisit this work from a design perspective, proposing guidelines for versatile search interfaces that are based on a modular approach to search. Inspired by aspects of search in physical environments, our recommendations address learning, creativity, inspiration, and pleasure as positive aspects of (book) search. Based on in-depth interviews with library patrons about search practises in physical and digital environments and drawing from previous work on search behaviour, we discuss search patterns as modular constructs consisting of micro-strategies. We illustrate how the structure of these patterns is highly flexible. Much like creative processes, they fluidly evolve based on learning and ideation during search, particularly in physical environments. This modular perspective provides a basis for designing interfaces that facilitate creative approaches to search in digital environments.

Software is typically developed incrementally and released in stages. Planning these releases involves deciding which features of the system should be implemented for each release. This is a complex planning process involving numerous trade-offs-constraints and factors that often make decisions difficult. Since the success of a product depends on this plan, it is important to understand the trade-offs between different release plans in order to make an informed choice. We present STRATOS, a tool that simultaneously visualizes several software release plans. The visualization shows several attributes about each plan that are important to planners. Multiple plans are shown in a single layout to help planners find and understand the trade-offs between alternative plans. We evaluated our tool via a qualitative study and found that STRATOS enables a range of decision-making processes, helping participants decide on which plan is most optimal.

Over a billion people use social networking sites like Facebook to maintain awareness of their friends. Facebook's News Feed is the primary mechanism by which people are shown updates about their friends' daily activities on the site in the form of an algorithmically curated list of stories. This paper examines how people browse the News Feed, their perceptions and satisfaction while using it, and the interactions they make with their personal social network. We conducted a qualitative study involving think-aloud semi-structured interviews as the participants casually browsed their own feeds. We observed a wide variation in the use of the News Feed ranging from careful consideration of social conventions, judgment of people, and annoyance and frustration towards certain friends. Our findings suggest that people do not deliberately curate their own News Feed either due to lack of awareness or perceived social repercussions.

We present A Delicate Agreement, an interactive art installation designed to intrigue viewers by offering them an unfolding story that is endlessly fascinating. To achieve this, we set our story in the liminal space of an elevator, and populated this elevator with a set of unique characters. Viewers watch the story unfold through peepholes in the elevator's doors, where in turn their gaze can trigger changes in the storyline. This storyline's interactive response was created via a complex adaptive system using simple rules based on Goffman's performance theory.

Abstract Hand‐drawn sketching on napkins or whiteboards is a common, accessible method for generating visual representations. This practice is shared by experts and non‐experts and is probably one of the faster and more expressive ways to draft a visual representation of data. In order to better understand the types of and variations in what people produce when sketching data, we conducted a qualitative study. We asked people with varying degrees of visualization expertise, from novices to experts, to manually sketch representations of a small, easily understandable dataset using pencils and paper and to report on what they learned or found interesting about the data. From this study, we extract a data sketching representation continuum from numeracy to abstraction; a data report spectrum from individual data items to speculative data hypothesis; and show the correspondence between the representation types and the data reports from our results set. From these observations we discuss the participants’ representations in relation to their data reports, indicating implications for design and potentially fruitful directions for research.

Data surrounds each and every one of us in our daily lives, ranging from exercise logs, to archives of our interactions with others on social media, to online resources pertaining to our hobbies. There is enormous potential for us to use these data to understand ourselves better and make positive changes in our lives. Visualization (Vis) and visual analytics (VA) offer substantial opportunities to help individuals gain insights about themselves, their communities and their interests; however, designing tools to support data analysis in non-professional life brings a unique set of research and design challenges. We investigate the requirements and research directions required to take full advantage of Vis and VA in a personal context. We develop a taxonomy of design dimensions to provide a coherent vocabulary for discussing personal visualization and personal visual analytics. By identifying and exploring clusters in the design space, we discuss challenges and share perspectives on future research. This work brings together research that was previously scattered across disciplines. Our goal is to call research attention to this space and engage researchers to explore the enabling techniques and technology that will support people to better understand data relevant to their personal lives, interests, and needs.

If visualization is to be democratized, we need to provide means for non-experts to create visualizations that allow them to engage directly with datasets. We present constructive visualization a new paradigm for the simple creation of flexible, dynamic visualizations. Constructive visualization is simple-in that the skills required to build and manipulate the visualizations are akin to kindergarten play; it is expressive in that one can build within the constraints of the chosen environment, and it also supports dynamics -- in that these constructed visualizations can be rebuilt and adjusted. We de- scribe the conceptual components and processes underlying constructive visualization, and present real-world examples to illustrate the utility of this approach. The constructive visualization approach builds on our inherent understanding and experience with physical building blocks, offering a model that enables non-experts to create entirely novel visualizations, and to engage with datasets in a manner that would not have otherwise been possible.

Interactive data exploration and manipulation are often hindered by dataset sizes. For 3D data, this is aggravated by occlusion, important adjacencies, and entangled patterns. Such challenges make visual interaction via common filtering techniques hard. We describe a set of realtime multi-dimensional data deformation techniques that aim to help users to easily select, analyze, and eliminate spatial-and-data patterns. Our techniques allow animation between view configurations, semantic filtering and view deformation. Any data subset can be selected at any step along the animation. Data can be filtered and deformed to reduce occlusion and ease complex data selections. Our techniques are simple to learn and implement, flexible, and real-time interactive with datasets of tens of millions of data points. We demonstrate our techniques on three domain areas: 2D image segmentation and manipulation, 3D medical volume exploration, and astrophysical exploration.

With new computer technologies portable devices are rapidly approaching the dimensions and characteristics of traditional pen and paper-based tools. Text and graphic documents are now commonly viewed using small tablet computers. We conducted a study with small groups of participants to better understand how paper-based text and graphics are used by small collaborative groups as compared to how these groups make use of documents presented on a digital tablet with digital styluses. Our results indicate that digital tools, as compared to paper tools, can affect the levels of verbal communication and participant gaze engagement with other group members. Additionally, we observed how participants spatially arranged paper-based and digital tools during collaborative group activities, how often they switched from digital to paper, and how they still prefer paper overall.

Abstract We introduce Papilio, a new visualization technique for visualizing permissions of real‐world Android applications. We explore the development of layouts that exploit the directed acyclic nature of Android application permission data to develop a new explicit layout technique that incorporates aspects of set membership, node‐link diagrams and matrix layouts. By grouping applications based on sets of requested permissions, a structure can be formed with partially ordered relations. The Papilio layout shows sets of applications centrally, the relations among applications on one side and application permissions, as the reason behind the existence of the partial order, on the other side. Using Papilio to explore a set of Android applications as a case study has led to new security findings regarding permission usage by Android applications.

The articles in this special issue present extended versions of the five best papers from the 2013 IEEE Pacific Visualization Symposium (PacificVis'13) which was held in Sydney, Australia from February 26 to March 1, 2013. The objective of this symposium series is to foster greater exchange between visualization researchers and practitioners, with a focus on the Asia-Pacific region.

The accessibility of infovis authoring tools to a wide audience has been identified as a major research challenge. A key task in the authoring process is the development of visual mappings. While the infovis community has long been deeply interested in finding effective visual mappings, comparatively little attention has been placed on how people construct visual mappings. In this paper, we present the results of a study designed to shed light on how people transform data into visual representations. We asked people to create, update and explain their own information visualizations using only tangible building blocks. We learned that all participants, most of whom had little experience in visualization authoring, were readily able to create and talk about their own visualizations. Based on our observations, we discuss participants' actions during the development of their visual representations and during their analytic activities. We conclude by suggesting implications for tool design to enable broader support for infovis authoring.

Although there has been widespread proliferation of creative-coding programming languages, the design of many toolkits and application programming interfaces (APIs) for expression and interactivity do not take full advantages of the unique space of mobile multitouch devices. In designing a new API for this space we first consider five major problem spaces and present an architecture that attempts to address these to move beyond the low-level manipulation of graphics giving first-class status to media objects.

A transmogrifier is a novel interface that enables quick, on-the-fly graphic transformations. A region of a graphic can be specified by a shape and transformed into a destination shape with real-time, visual feedback. Both origin and destination shapes can be circles, quadrilaterals or arbitrary shapes defined through touch. Transmogrifiers are flexible, fast and simple to create and invite use in casual InfoVis scenarios, opening the door to alternative ways of exploring and displaying existing visualizations (e.g., rectifying routes or rivers in maps), and enabling free-form prototyping of new visualizations (e.g., lenses).

Portable paper calendars (i. e., day planners and organizers) have greatly influenced the design of group electronic calendars. Both use time units (hours/days/weeks/etc.) to organize visuals, with useful information (e.g., event types, locations, attendees) usually presented as - perhaps abbreviated or even hidden - text fields within those time units. The problem is that, for a group, this visual sorting of individual events into time buckets conveys only limited information about the social network of people. For example, people's whereabouts cannot be read 'at a glance' but require examining the text. Our goal is to explore an alternate visualization that can reflect and illustrate group members' calendar events. Our main idea is to display the group's calendar events as spatiotemporal activities occurring over a geographic space animated over time, all presented on a highly interactive public display. In particular, our Spalendar (Spatial Calendar) design animates people's past, present and forthcoming movements between event locations as well as their static locations. Detail of people's events, their movements and their locations is progressively revealed and controlled by the viewer's proximity to the display, their identity, and their gestural interactions with it, all of which are tracked by the public display.

We present Fluid Views, a web-based search environment designed to bridge overview and detail by integrating dynamic queries, semantic zooming, and dual layers. The most common form of search results is long ranked and paginated lists, which are seldom examined beyond the top ten items. To support more exploratory forms of information seeking, we bring together the notion of relevance with the power of visual encoding. In Fluid Views, results portray relevance via size and detail in a dynamic top layer and semantic similarity via position on a base map. We designed Fluid Views with temporal, spatial, and content-defined base maps for both textual and visual resources, and tested our prototype system on books, blogs, and photos. Interviews with library professionals indicate the potential of Fluid Views for exploring collections and exciting directions for future research.

In this paper we explore numeric typeface design for visualization purposes. We introduce FatFonts, a technique for visualizing quantitative data that bridges the gap between numeric and visual representations. FatFonts are based on Arabic numerals but, unlike regular numeric typefaces, the amount of ink (dark pixels) used for each digit is proportional to its quantitative value. This enables accurate reading of the numerical data while preserving an overall visual context. We discuss the challenges of this approach that we identified through our design process and propose a set of design goals that include legibility, familiarity, readability, spatial precision, dynamic range, and resolution. We contribute four FatFont typefaces that are derived from our exploration of the design space that these goals introduce. Finally, we discuss three example scenarios that show how FatFonts can be used for visualization purposes as valuable representation alternatives.

When exploiting the power of node-link diagrams to represent real-world data such as web structures, airline routes, electrical, telecommunication and social networks, link congestion frequently arises. Such areas in the diagram---with dense, overlapping links---are not readable connectivity, node shapes, labels, and contextual information are obscured. In response, graph-layout research has begun to consider the modification of link shapes with techniques such as link routing and bundling. In this paper, we delve into the interactive techniques afforded by variant use of link curvature, delineating a six-dimensional design space that is populated by four families of interactive techniques: bundling, fanning, magnets, and legends. Our taxonomy encompasses existing techniques and reveals several novel link interactions. We describe the implementation of these techniques and illustrate their potential for exploring dense graphs with multiple types of links.

Serendipity, a trigger of exciting yet unexpected discoveries, is an important but comparatively neglected factor in information seeking, research, and ideation. We suggest that serendipity can be facilitated through visualization. To explore this, we introduce the Bohemian Bookshelf, which aims to support serendipitous discoveries in the context of digital book collections. The Bohemian Bookshelf consists of five interlinked visualizations each offering a unique overview of the collection. It aims at encouraging serendipity by (1) offering multiple visual access points to the collection, (2) highlighting adjacencies between books, (3) providing flexible visual pathways for exploring the collection, (4) enticing curiosity through abstract, metaphorical, and visually distinct representations of books, and (5) enabling a playful approach to information exploration. A deployment at a library revealed that visitors embraced this approach of utilizing visualization to support open-ended explorations and serendipitous discoveries. This encourages future explorations into promoting serendipity through information visualization.

We take a new, scenario-based look at evaluation in information visualization. Our seven scenarios, evaluating visual data analysis and reasoning, evaluating user performance, evaluating user experience, evaluating environments and work practices, evaluating communication through visualization, evaluating visualization algorithms, and evaluating collaborative data analysis were derived through an extensive literature review of over 800 visualization publications. These scenarios distinguish different study goals and types of research questions and are illustrated through example studies. Through this broad survey and the distillation of these scenarios, we make two contributions. One, we encapsulate the current practices in the information visualization research community and, two, we provide a different approach to reaching decisions about what might be the most effective evaluation of a given information visualization. Scenarios can be used to choose appropriate research questions and goals and the provided examples can be consulted for guidance on how to design one's own study.

The importance of interaction to Information Visualization (InfoVis) and, in particular, of the interplay between interactivity and cognition is widely recognized [12, 15, 32, 55, 70]. This interplay, combined with the demands from increasingly large and complex datasets, is driving the increased significance of interaction in InfoVis. In parallel, there have been rapid advances in many facets of interaction technologies. However, InfoVis interactions have yet to take full advantage of these new possibilities in interaction technologies, as they largely still employ the traditional desktop, mouse, and keyboard setup of WIMP (Windows, Icons, Menus, and a Pointer) interfaces. In this paper, we reflect more broadly about the role of more "natural" interactions for InfoVis and provide opportunities for future research. We discuss and relate general HCI interaction models to existing InfoVis interaction classifications by looking at interactions from a novel angle, taking into account the entire spectrum of interactions. Our discussion of InfoVis-specific interaction design considerations helps us identify a series of underexplored attributes of interaction that can lead to new, more "natural," interaction techniques for InfoVis.

Current interfaces for common information visualizations such as bar graphs, line graphs, and scatterplots usually make use of the WIMP (Windows, Icons, Menus and a Pointer) interface paradigm with its frequently discussed problems of multiple levels of indirection via cascading menus, dialog boxes, and control panels. Recent advances in interface capabilities such as the availability of pen and touch interaction challenge us to re-think this and investigate more direct access to both the visualizations and the data they portray. We conducted a Wizard of Oz study to explore applying pen and touch interaction to the creation of information visualization interfaces on interactive whiteboards without implementing a plethora of recognizers. Our wizard acted as a robust and flexible pen and touch recognizer, giving participants maximum freedom in how they interacted with the system. Based on our qualitative analysis of the interactions our participants used, we discuss our insights about pen and touch interactions in the context of learnability and the interplay between pen and touch gestures. We conclude with suggestions for designing pen and touch enabled interactive visualization interfaces.

We propose a new way of navigating the Web using interactive information visualizations, and present encouraging results from a large-scale Web study of a visual exploration system. While the Web has become an immense, diverse information space, it has also evolved into a powerful software platform. We believe that the established interaction techniques of searching and browsing do not sufficiently utilize these advances, since information seekers have to transform their information needs into specific, text-based search queries resulting in mostly text-based lists of resources. In contrast, we foresee a new type of information seeking that is high-level and more engaging, by providing the information seeker with interactive visualizations that give graphical overviews and enable query formulation. Building on recent work on faceted navigation, information visualization, and exploratory search, we conceptualize this type of information navigation as visual exploration and evaluate a prototype Web-based system that implements it. We discuss the results of a large-scale, mixed-method Web study that provides a better understanding of the potential benefits of visual exploration on the Web, and its particular performance challenges.

We introduce the information flaneur as a new human-centred view on information seeking that is grounded in interdisciplinary research. We use the metaphor of the urban flaneur making sense of a city as an inspiring lens that brings together diverse perspectives. These perspectives shift information seeking towards a more optimistic outlook: the information flaneur represents curious, creative, and critical information seeking. The resulting information-seeking model conceptualizes the interrelated nature between information activities and experiences as a continuum between horizontal exploration and vertical immersion. Motivated by enabling technological trends and inspired by the information flaneur, we present explorability as a new guiding principle for design and raise research challenges regarding the representation of information abstractions and details.

In this paper we describe our findings from a field study that was conducted at the Vancouver Aquarium to investigate how visitors interact with a large interactive table exhibit using multi-touch gestures. Our findings show that the choice and use of multi-touch gestures are influenced not only by general preferences for certain gestures but also by the interaction context and social context they occur in. We found that gestures are not executed in isolation but linked into sequences where previous gestures influence the formation of subsequent gestures. Furthermore, gestures were used beyond the manipulation of media items to support social encounters around the tabletop exhibit. Our findings indicate the importance of versatile many-to-one mappings between gestures and their actions that, other than one-to-one mappings, can support fluid transitions between gestures as part of sequences and facilitate social information exploration.

Abstract Detail‐in‐context lens techniques can be useful for exploring visualizations of data spaces that are too large or have too much detail to fit in regular displays. For example, by bending the space in the right way we can bring together details from two separate areas for easy comparison while roughly keeping the context that situates each area within the global space. While these techniques can be powerful tools, they also introduce distortions that need to be understood, and often the tools have to be disabled in order to have access to the undistorted data. We introduce the undistort lens, a complement to existing distortion‐based techniques that provides a local and separate presentation of the original geometry without affecting any distortion‐based lenses currently used in the presentation. The undistort lens is designed to allow interactive access to the underlying undistorted data within the context of the distorted space, and to enable a better understanding of the distortions. The paper describes the implementation of a generic back‐mapping mechanism that enables the implementation of undistort lenses for arbitrary distortion based techniques, including those presented in the lens literature. We also provide a series of use‐case scenarios that demonstrate the situations in which the technique can complement existing lenses.

While it is still most common for information visualization researchers to develop new visualizations from a data- or taskdriven perspective, there is growing interest in understanding the types of visualizations people create by themselves for personal use. As part of this recent direction, we have studied a large collection of whiteboards in a research institution, where people make active use of combinations of words, diagrams and various types of visuals to help them further their thought processes. Our goal is to arrive at a better understanding of the nature of visuals that are created spontaneously during brainstorming, thinking, communicating, and general problem solving on whiteboards. We use the qualitative approaches of open coding, interviewing, and affinity diagramming to explore the use of recognizable and novel visuals, and the interplay between visualization and diagrammatic elements with words, numbers and labels. We discuss the potential implications of our findings on information visualization design.

We present the iterative design of a virtual sandtray application for a tabletop display. The purpose of our prototype is to support sandtray therapy, a form of art therapy typically used for younger clients. A significant aspect of this therapy is the insight gained by the therapist as they observe the client interact with the figurines they use to create a scene in the sandtray. In this manner, the therapist can gain increased understanding of the client's psyche. We worked with three sandtray therapists throughout the evolution of our prototype. We describe the details of the three phases of this design process: initial face-to-face meetings, iterative design and development via distance collaboration, and a final face-to-face feedback session. This process revealed that our prototype was sufficient for therapists to gain insight about a person's psyche through their interactions with the virtual sandtray.

In this paper, we present results from a study of collocated group console gaming. We focus, in particular, on observed gaming practices that emphasized the individual gamer within a gaming group as well as practices that emphasized the gaming group as a whole. We relate each of these practices, where possible, to specific elements of the game design including game mechanics, interaction design, and special effects design. We argue that the classic distinction between competitive and cooperative modes of gameplay does not fully transfer to account for the interpersonal dynamics within collocated gaming groups.

Distributed physical user interfaces comprise networked sensors, actuators and other devices attached to a variety of computers in different locations. Developing such systems is no easy task. It is hard to track the location and status of component devices, even harder to understand, validate, test and debug how events are transmitted between devices, and hardest yet to see if the overall system behaves correctly. Our Visual Environment Explorer supports developers of these systems by visualizing the location and status of individual and/or aggregate devices. It visualizes the current event flow between devices as they are received and transmitted, as well as the event history. Events are displayable at various levels of detail. The visualization also shows the activity of applications that use these physical devices. The tool is highly interactive: developers can explore system behavior through spatial navigation, zooming, multiple simultaneous views, event filtering, details-on-demand, and time-dependent semantic zooming.

This article presents a framework of 6 distinct yet interrelated factors for describing information flow that arose from a combination of field studies in a hospital ward and a review of literature. These studies investigated the dynamics of nurses' information flow, focusing on shift change. The InfoFlow Framework's 6 interrelated factors that affect the information flow are information, personnel, artifacts, spatiality, temporality, and communication mode. The framework is presented as a tool for evaluating new health care technologies. The 6 factors and their interrelationships are described first. Next, this structure is applied as a tool to aid in the analysis of the data generated in a study that assesses technology in use. Then the use of the framework is illustrated by structuring it as a set of questions that can be used as a guide for other researchers to generate coherent descriptions of the information flow and to evaluate technology deployments. Finally, there is a discussion of areas where the InfoFlow framework may be applied to allow an evaluation of the extent to which the framework may be generalized to other settings.

We introduce the concept of a Visual Backchannel as a novel way of following and exploring online conversations about large-scale events. Microblogging communities, such as Twitter, are increasingly used as digital backchannels for timely exchange of brief comments and impressions during political speeches, sport competitions, natural disasters, and other large events. Currently, shared updates are typically displayed in the form of a simple list, making it difficult to get an overview of the fast-paced discussions as it happens in the moment and how it evolves over time. In contrast, our Visual Backchannel design provides an evolving, interactive, and multi-faceted visual overview of large-scale ongoing conversations on Twitter. To visualize a continuously updating information stream, we include visual saliency for what is happening now and what has just happened, set in the context of the evolving conversation. As part of a fully web-based coordinated-view system we introduce Topic Streams, a temporally adjustable stacked graph visualizing topics over time, a People Spiral representing participants and their activity, and an Image Cloud encoding the popularity of event photos by size. Together with a post listing, these mutually linked views support cross-filtering along topics, participants, and time ranges. We discuss our design considerations, in particular with respect to evolving visualizations of dynamically changing data. Initial feedback indicates significant interest and suggests several unanticipated uses.

Tag clouds have proliferated over the web over the last decade. They provide a visual summary of a collection of texts by visually depicting the tag frequency by font size. In use, tag clouds can evolve as the associated data source changes over time. Interesting discussions around tag clouds often include a series of tag clouds and consider how they evolve over time. However, since tag clouds do not explicitly represent trends or support comparisons, the cognitive demands placed on the person for perceiving trends in multiple tag clouds are high. In this paper, we introduce SparkClouds, which integrate sparklines into a tag cloud to convey trends between multiple tag clouds. We present results from a controlled study that compares SparkClouds with two traditional trend visualizations—multiple line graphs and stacked bar charts—as well as Parallel Tag Clouds. Results show that SparkClouds ability to show trends compares favourably to the alternative visualizations.

Hospital work coordination and collaboration often requires mobility for acquiring proper information and resources. In turn, the spatial distribution and the mobility of clinicians can curtail the opportunities for effective communications making collaboration difficult. In this situation, a mobile hands-free voice communication system, Vocera, was introduced to enhance communication. It supports quick and impromptu conversations among coworkers for work coordination and collaboration anytime and anywhere. We study this deployment and present our findings concerning the impact of this communication system on the information flow. Our information flow framework's communication strategies help contrast the information processes before and after the deployment of Vocera.

Abstract Textual data is at the forefront of information management problems today. One response has been the development of visualizations of text data. These visualizations, commonly based on simple attributes such as relative word frequency, have become increasingly popular tools. We extend this direction, presenting the first visualization of document content which combines word frequency with the human‐created structure in lexical databases to create a visualization that also reflects semantic content. DocuBurst is a radial, space‐filling layout of hyponymy (the IS‐A relation), overlaid with occurrence counts of words in a document of interest to provide visual summaries at varying levels of granularity. Interactive document analysis is supported with geometric and semantic zoom, selectable focus on individual words, and linked access to source text.

While many data sets contain multiple relationships, depicting more than one data relationship within a single visualization is challenging. We introduce Bubble Sets as a visualization technique for data that has both a primary data relation with a semantically significant spatial organization and a significant set membership relation in which members of the same set are not necessarily adjacent in the primary layout. In order to maintain the spatial rights of the primary data relation, we avoid layout adjustment techniques that improve set cluster continuity and density. Instead, we use a continuous, possibly concave, isocontour to delineate set membership, without disrupting the primary layout. Optimizations minimize cluster overlap and provide for calculation of the isocontours at interactive speeds. Case studies show how this technique can be used to indicate multiple sets on a variety of common visualizations.

Large multi-touch displays are expanding the possibilities of multiple-coordinated views by allowing multiple people to interact with data in concert or independently. We present Lark, a system that facilitates the coordination of interactions with information visualizations on shared digital workspaces. We focus on supporting this coordination according to four main criteria: scoped interaction, temporal flexibility, spatial flexibility, and changing collaboration styles. These are achieved by integrating a representation of the information visualization pipeline into the shared workspace, thus explicitly indicating coordination points on data, representation, presentation, and view levels. This integrated meta-visualization supports both the awareness of how views are linked and the freedom to work in concert or independently. Lark incorporates these four main criteria into a coherent visualization collaboration interaction environment by providing direct visual and algorithmic support for the coordination of data analysis actions over shared large displays.

This paper reports the findings from two field studies that reveal paper-based artifacts being heavily relied upon in medical shift work despite the deployment of a mobile technology in a local hospital ward. We present the information flow in terms of common and personal information spaces and identify three important functions of these personal artifacts in the actual work practices. Artifacts serve as a bedside information source for patient care delivery, an opportune notepad and an information basis for reporting and handover. We thus recommend a system employing digital pens and paper so that nurses can retain the manual practice of constructing their personal artifacts, flexibly use them in the actual work and easily formalize the informal information recorded therein. We also discuss the benefits and challenges of our proposed technology.

To design information visualization tools for collaborative use, we need to understand how teams engage with visualizations during their information analysis process. We report on an exploratory study of individuals, pairs, and triples engaged in information analysis tasks using paper-based visualizations. From our study results, we derive a framework that captures the analysis activities of co-located teams and individuals. Comparing this framework with existing models of the information analysis process suggests that information visualization tools may benefit from providing a flexible temporal flow of analysis actions.

Since health care teams are often distributed across time and location, information sharing is crucial for effective patient care. Studying the use of a mobile information technology in a local hospital ward at two months and eleven months after its deployment identifies both short- and long-term phenomena and reveals a mismatch between the intentions behind the deployed mobile technology and the nurses' current work practices. We contrast the new mobile technology with the paper artifacts that were previously relied upon in nursing work. Finally, in light of these findings, we suggest design directions for future technology to support the nursing shift work.

Abstract In this paper we present several techniques to interactively explore representations of 2D vector fields. Through a set of simple hand postures used on large, touch‐sensitive displays, our approach allows individuals to custom‐design glyphs (arrows, lines, etc.) that best reveal patterns of the underlying dataset. Interactive exploration of vector fields is facilitated through freedom of glyph placement, glyph density control, and animation. The custom glyphs can be applied individually to probe specific areas of the data but can also be applied in groups to explore larger regions of a vector field. Re‐positionable sources from which glyphs—animated according to the local vector field—continue to emerge are used to examine the vector field dynamically. The combination of these techniques results in an engaging visualization with which the user can rapidly explore and analyze varying types of 2D vector fields, using a virtually infinite number of custom‐designed glyphs.

In common Web-based search interfaces, it can be difficult to formulate queries that simultaneously combine temporal, spatial, and topical data filters. We investigate how coordinated visualizations can enhance search and exploration of information on the World Wide Web by easing the formulation of these types of queries. Drawing from visual information seeking and exploratory search, we introduce VisGets--interactive query visualizations of Web-based information that operate with online information within a Web browser. VisGets provide the information seeker with visual overviews of Web resources and offer a way to visually filter the data. Our goal is to facilitate the construction of dynamic search queries that combine filters from more than one data dimension. We present a prototype information exploration system featuring three linked VisGets (temporal, spatial, and topical), and used it to visually explore news items from online RSS feeds.

Digital information displays are becoming more common in public spaces such as museums, galleries, and libraries. However, the public nature of these locations requires special considerations concerning the design of information visualization in terms of visual representations and interaction techniques. We discuss the potential for, and challenges of, information visualization in the museum context based on our practical experience with EMDialog, an interactive information presentation that was part of the Emily Carr exhibition at the Glenbow Museum in Calgary. EMDialog visualizes the diverse and multi-faceted discourse about this Canadian artist with the goal to both inform and provoke discussion. It provides a visual environment that allows for exploration of the interplay between two integrated visualizations, one for information access along temporal, and the other along contextual dimensions. We describe the results of an observational study we conducted at the museum that revealed the different ways visitors approached and interacted with EMDialog, as well as how they perceived this form of information presentation in the museum context. Our results include the need to present information in a manner sufficiently attractive to draw attention and the importance of rewarding passive observation as well as both short- and longer term information exploration.

On traditional tables, people frequently use the third dimension to pile, sort and store objects. However, while effective and informative for organization, this use of the third dimension does not usually extend far above the table. To enrich interaction with digital tables, we present the concept of shallow-depth 3D -- 3D interaction with limited depth. Within this shallow-depth 3D environment several common interaction methods need to be reconsidered. Starting from any of one, two and three touch points, we present interaction techniques that provide control of all types of 3D rotation coupled with translation (6DOF) on a direct-touch tabletop display. The different techniques exemplify a wide range of interaction possibilities: from the one-touch technique, which is designed to be simple and natural, but inherits a degree of imprecision from its simplicity; through to three-touch interaction, which allows precise bimanual simultaneous control of multiple degrees of freedom, but at the cost of simplicity. To understand how these techniques support interaction in shallow-depth 3D, we present a user study that examines the efficiency of, and preferences for, the techniques developed. Results show that users are fastest and most accurate when using the three-touch technique and that their preferences were also strongly in favour of the expressive power available from three-touch.

We present an observational study that was conducted to guide the design and development of technologies to support information flow during nurses' shift change in a hospital ward. Our goal is to find out how the complex information sharing processes during nurses' brief shift change unfold in a hospital setting. Our study shows the multitude of information media that nurses access during the parallel processes of information assembly and disassembly: digital, paper-based, displayed and verbal media. An initial analysis reveals how the common information spaces, where information media are positioned and accessible by all participants, are actively used and how they interact with the personal information spaces ephemerally constructed by the participants. Several types of information are consistently transposed from the common information spaces to the personal information space including: demographics, historical data, reminders and to-dos, alerts, prompts, scheduling and reporting information. Information types are often enhanced with a variety of visual cues to help nurses carry out their tasks.

Lattice graphs are used as underlying data structures in many statistical processing systems, including natural language processing. Lattices compactly represent multiple possible outputs and are usually hidden from users. We present a novel visualization intended to reveal the uncertainty and variability inherent in statistically-derived lattice structures. Applications such as machine translation and automated speech recognition typically present users with a best-guess about the appropriate output, with apparent complete confidence. Through case studies we show how our visualization uses a hybrid layout along with varying transparency, colour, and size to reveal the lattice structure, expose the inherent uncertainty in statistical processing, and help users make better-informed decisions about statistically-derived outputs.

With the ubiquity of typed text, the style and much of the personality of handwriting has been lost from general communication. To counter this we introduce an artistic real-time visualization of typed messages that additionally captures and encodes aspects of an individual's unique typing style. The potential of our system to augment electronic communication was evaluated and the results are provided along with analysis of their implications for social visualization.

We present VisLink, a method by which visualizations and the relationships between them can be interactively explored. VisLink readily generalizes to support multiple visualizations, empowers inter-representational queries, and enables the reuse of the spatial variables, thus supporting efficient information encoding and providing for powerful visualization bridging. Our approach uses multiple 2D layouts, drawing each one in its own plane. These planes can then be placed and re-positioned in 3D space: side by side, in parallel, or in chosen placements that provide favoured views. Relationships, connections, and patterns between visualizations can be revealed and explored using a variety of interaction techniques including spreading activation and search filters.

In many domains increased collaboration has lead to more innovation by fostering the sharing of knowledge, skills, and ideas. Shared analysis of information visualizations does not only lead to increased information processing power, but team members can also share, negotiate, and discuss their views and interpretations on a dataset and contribute unique perspectives on a given problem. Designing technologies to support collaboration around information visualizations poses special challenges and relatively few systems have been designed. We focus on supporting small groups collaborating around information visualizations in a co-located setting, using a shared interactive tabletop display. We introduce an analysis of challenges and requirements for the design of co-located collaborative information visualization systems. We then present a new system that facilitates hierarchical data comparison tasks for this type of collaborative work. Our system supports multi-user input, shared and individual views on the hierarchical data visualization, flexible use of representations, and flexible workspace organization to facilitate group work around visualizations.

Teams that are geographically distributed often share information both in real-time and asynchronously. When such sharing is through groupware, change conflicts can arise when people pursue parallel and competing actions on the same information. This leads to problems in how the systems and its users maintain a consistent view of shared information across distance and time. We explore change awareness of conflicts in a three-dimensional distributed shared space. Our user study compares the use of visual feedback to an optimistic concurrency control strategy for both synchronous and asynchronous distributed groupware. Our feedback provides a means for synchronous users to recognize and resolve real-time changes, and for asynchronous users to view and resolve changes when switching from an offline to online mode of work. Results of our study suggest that the visual feedback serves as a useful feedthrough mechanism in the synchronous case, but that asynchronous users may be overwhelmed by the quantity of changes if they come online after many changes have been made.

Tabletop displays provide exciting opportunities to support individual and collaborative activities such as planning, organizing, and storyboarding. It has been previously suggested that continuous flow of interface items can ease information access and exploration on a tabletop workspace, yet this concept has not been adequately studied. This paper presents an exploratory user study of Interface Currents, a reconfigurable and mobile tabletop interface component that offers a controllable flow for interface items placed on its surface. Our study shows that Interface Currents supported information access and sharing on a tabletop workspace. The study findings also demonstrate that mobility, flexibility, and general adjustability of Interface Currents are important factors in providing interface support for variations in task and group interactions.

Designing collaborative interfaces for tabletops remains difficult because we do not fully understand how groups coordinate their actions when working collaboratively over tables. We present two observational studies of pairs completing independent and shared tasks that investigate collaborative coupling, or the manner in which collaborators are involved and occupied with each other's work. Our results indicate that individuals frequently and fluidly engage and disengage with group activity through several distinct, recognizable states with unique characteristics. We describe these states and explore the consequences of these states for tabletop interface design.

Motivations for drawing hierarchical structures are probably as diverse as datasets to visualize. This ubiquity of tree structures has lead to a manifold of tree layout algorithms and tree visualization systems. While many tree layouts exist, increasingly massive data sets, expanding computational power, and still relatively limited display space make tree layout algorithms a topic of ongoing interest. We explore the use of nature’s phyllotactic patterns to inform the layout of hierarchical data. These naturally occurring patterns provide a non-overlapping, optimal packing when the total number of nodes is not known a priori. We present PhylloTrees, a family of expandable tree layouts based on these patterns.

Previous research has shown that rotation and orientation of items plays three major roles during collaboration: comprehension, coordination and communication. Based on these roles of orientation and advice from kinesiology research, we have designed the Rotate'N Translate (RNT) interaction mechanism, which provides integrated control of rotation and translation using only a single touch-point for input. We present an empirical evaluation comparing RNT to a common rotation mechanism that separates control of rotation and translation. Results of this study indicate RNT is more efficient than the separate mechanism and better supports the comprehension, coordination and communication roles of orientation.

In this paper we present, ARCTREES, a novel way of visualizing hierarchical and non-hierarchical relations within one interactive visualization. Such a visualization is challenging because it must display hierarchical information in a way that the user can keep his or her mental map of the data set and include relational information without causing misinterpretation. We propose a hierarchical view derived from traditional Treemaps and augment this view with an arc diagram to depict relations. In addition, we present interaction methods that allow the exploration of the data set using Focus+Context techniques for navigation. The development was motivated by a need for understanding relations in structured documents but it is also useful in many other application domains such as project management and calendars.

Understanding complex 3D virtual models can be difficult, especially when the model has interior components not initially visible and ancillary text. We describe new techniques for the interactive exploration of 3D models. Specifically, in addition to traditional viewing operations, we present new text extrusion techniques combined with techniques that create an interactive explosion diagram. In our approach, scrollable text annotations that are associated with the various parts of the model can be revealed dynamically, either in part or in full, by moving the mouse cursor within annotation trigger areas. Strong visual connections between model parts and the associated text are included in order to aid comprehension. Furthermore, the model parts can be separated, creating interactive explosion diagrams. Using a 3D probe, occluding objects can be interactively moved apart and then returned to their initial locations. Displayed annotations are kept readable despite model manipulations. Hence, our techniques provide textual context within the spatial context of the 3D model.

Researchers seeking alternatives to traditional desktop computers have begun exploring the potential collaborative benefits of digital tabletop displays. However, there are still many open issues related to the design of collaborative tabletop interfaces, such as whether these systems should automatically orient workspace items or enforce ownership of workspace content. Understanding the natural interaction practices that people use during tabletop collaboration with traditional media (e.g., pen and paper) can help to address these issues. Interfaces that are modeled on these practices will have the additional advantage of supporting the interaction skills people have developed over years of collaborating at traditional tables. To gain a deeper understanding of these interaction practices we conducted two observational studies of traditional tabletop collaboration in both casual and formal settings. Our results reveal that collaborators use three types of tabletop territories to help coordinate their interactions within the shared tabletop workspace: personal, group, and storage territories. Findings from a spatial analysis of collaborators' tabletop interactions reveal important properties of these tabletop territories. In order to provide a comprehensive picture of the role of tabletop territoriality in collaboration, we conclude with a synthesis of our findings and previous research findings and with several relevant design implications.

The difficulty of accessing information details while preserving context has generated many different focus-incontext techniques. A common limitation of focus-incontext techniques is their ability to work well at high magnification. We present a set of improvements that will make high magnification in context more feasible. We demonstrate new distortion functions that effectively integrate high magnification within its context. Finally, we show how lenses can be used on top of other lenses, effectively multiplying their magnification power in the same manner that a magnifying glass applied on top of another causes multiplicative magnification. The combined effect is to change feasible detail-in-context magnification factors from less than 8 to more than 40.

In order to support co-located collaboration, many researchers are now investigating how to effectively augment tabletops with electronic displays. As far back as 1988, orientation was recognized as a significant human factor issue that must be addressed by electronic tabletop designers. As with traditional tables, when people stand at different positions around a horizontal display they will be viewing the contents from different angles. One common solution to this problem is to have the software reorient objects so that any given individual can view them 'right way up.' Yet is this the best approach? If not, how do people actually use orientation on tables? To answer these questions, we conducted an observational study of collaborative activity on a traditional table. Our results show that the strategy of reorienting objects to a person's view is overly simplistic: while important, it is an incomplete view of how people exploit their ability to reorient objects. Orientation proves critical in how individuals comprehend information, how collaborators coordinate their actions, and how they mediate communication. The coordinating role of orientation is evident in how people establish personal and group spaces, and how they signal ownership of objects. In terms of communication, orientation is useful in initiating communicative exchanges and in continuing to speak to individuals about particular objects and work patterns as collaboration progresses. The three roles of orientation have significant implications for the design of tabletop software and the assessment of existing tabletop systems.

In this paper a visual tool for comparing different mountain pine-beetle management approaches is presented. This comparison tool gives the users the possibility of viewing their information, but more importantly it provides the ability to visually see the similarities and the differences between two simulations. This tool can help users to make decisions regarding their future actions against beetle attacks. The technique used is based on colour indexing combined with the mapping of the strategies into colour histograms. The system is entitled VICO from the phrase Visual Comparison.

Human dialogue is so complex that definitively analysing patterns of conversation may well be impossible. Within a conversation, all the complexities and ambiguities of natural language exist and each speaker will have his/her own speech characteristics and moods. Examining these characteristics through text dialog can be a demanding cognitive task. One reason is because the whole conversation cannot be viewed at one time. This task can be made more convenient if there is a way of visualising all this information at once through graphical patterns. Graphical patterns can revolve around the conversation, creating an abstract piece of artwork. From these patterns, one can guess at the speaker's emotion and how he/she is connected to another speaker during a conversation. This paper discusses the different visualisation techniques that are used to represent several aspects of a conversation.

GeneVis provides a visual environment for exploring the dynamics of genetic regulatory networks. At present time, genetic regulation is the focus of intensive research worldwide, and computational aids are being called for to help in the research of factors that are difficult to observe directly. GeneVis provides a particle-based simulation of genetic networks and visualizes the process of this simulation as it occurs. Two dynamic visualization techniques are provided, a visualization of the movement of the regulatory proteins and a visualization of the relative concentrations of these proteins. Several interactive tools relate the dynamic visualizations to the underlying genetic network structure.

Making effective use of the available display space has long been a fundamental issue in user interface design. We live in a time of rapid advances in available CPU power and memory. However, the common sizes of our computational display spaces have only minimally increased or in some cases, such as hand held devices, actually decreased. In addition, the size and scope of the information spaces we wish to explore are also expanding. Representing vast amounts of information on our relatively small screens has become increasingly problematic and has been associated with problems in navigation, interpretation and recognition. User interface research has proposed several differing presentation approaches to address these problems. These methods create displays that vary considerably, visually and algorithmically. We present a unified framework that provides a way of relating seemingly distinct methods, facilitating the inclusion of more than one presentation method in a single interface. Furthermore, it supports extrapolation between the presentation methods it describes. Of particular interest are the presentation possibilities that exist in the ranges between various distortion presentations, magnified insets and detail-in-context presentations, and between detail-in-context presentations and a full-zooming environment. This unified framework offers a geometric presentation library in which presentation variations are available independently of the mode of graphic representation. The intention is to promote the ease of exploration and experimentation into the use of varied presentation combinations.

Medical image analysis is shifting from current film oriented light screen environments to computer environments that involve viewing and analyzing large sets of images on a computer screen. Magnetic resonance imaging (MRI) studies, in particular, can involve many images. The paper examines how best to meet the needs of radiologists in a computational environment. To this end, a field study was conducted to observe radiologists' interactions during MRI analysis in the traditional light screen environment. Key issues uncovered involve control over focus and context, dynamic grouping of images and retrieval of images and image groups. To address the problem of focus and context, existing layout adjustment and magnification techniques are explored to provide the most appropriate solution. Our interest is in combining the methodologies of human computer interaction studies with computational presentation possibilities to design a visual environment for the crucial field of medical image analysis.

As ecological awareness increases there has been a shift towards more integrated forest management. Accurate modeling of future states of forested landscapes will allow better planning for safeguarding our forest resource for future generations. We present an initial exploration into providing visual access to information generated by SELES (Spatially Explicit Landscape Event Simulator). We explore the application of our visual access distortion technique to a block of temporal data created from a sequence of landscape event based information. This type of access extends the possibilities of visual exploration for temporal and spatial interrelations in a data set.

A fundamental issue in user interface design is the effective use of available screen space, commonly referred to as the screen real estate problem.This paper presents a new distortion-based viewing tool for exploring large information spaces through the use of a three-dimensional pliable surface.Arbitrarily-shaped regions (foci) on the surface may be selected and pulled towards or pushed away from the viewer thereby increasing or decreasing the level of detail contained within each region.Furthermore, multiple foci are smoothly blended together such that there is no loss of context.The manipulation and blending of foci is accomplished using a fairly simple mathematical model based on gaussian curves.The significance of this approach is that it utilizes precognitive perceptual cues about the three-dimensional surface to make the distortions comprehensible, and allows the user to interactively control the location, shape, and extent of the distortion in very large graphs or maps.