Conference stringclasses 6 values | Year int64 1.99k 2.03k | Title stringlengths 8 187 | DOI stringlengths 16 32 | Abstract stringlengths 128 7.15k ⌀ | Accessible bool 2 classes | Early bool 2 classes | AuthorNames-Deduped listlengths 1 24 | Award listlengths 0 2 | Resources listlengths 0 5 | ResourceLinks listlengths 0 10 |
|---|---|---|---|---|---|---|---|---|---|---|
VAST | 2,008 | Multivariate visual explanation for high dimensional datasets | 10.1109/VAST.2008.4677368 | Understanding multivariate relationships is an important task in multivariate data analysis. Unfortunately, existing multivariate visualization systems lose effectiveness when analyzing relationships among variables that span more than a few dimensions. We present a novel multivariate visual explanation approach that helps users interactively discover multivariate relationships among a large number of dimensions by integrating automatic numerical differentiation techniques and multidimensional visualization techniques. The result is an efficient workflow for multivariate analysis model construction, interactive dimension reduction, and multivariate knowledge discovery leveraging both automatic multivariate analysis and interactive multivariate data visual exploration. Case studies and a formal user study with a real dataset illustrate the effectiveness of this approach. | false | false | [
"Scott Barlowe",
"Tianyi Zhang",
"Yujie Liu",
"Jing Yang 0001",
"Donald J. Jacobs"
] | [] | [] | [] |
VAST | 2,008 | Narratives: A visualization to track narrative events as they develop | 10.1109/VAST.2008.4677364 | Analyzing unstructured text streams can be challenging. One popular approach is to isolate specific themes in the text, and to visualize the connections between them. Some existing systems, like ThemeRiver, provide a temporal view of changes in themes; other systems, like In-Spire, use clustering techniques to help an analyst identify the themes at a single point in time. Narratives combines both of these techniques; it uses a temporal axis to visualize ways that concepts have changed over time, and introduces several methods to explore how those concepts relate to each other. Narratives is designed to help the user place news stories in their historical and social context by understanding how the major topics associated with them have changed over time. Users can relate articles through time by examining the topical keywords that summarize a specific news event. By tracking the attention to a news article in the form of references in social media (such as weblogs), a user discovers both important events and measures the social relevance of these stories. | false | false | [
"Danyel Fisher",
"Aaron Hoff",
"George G. Robertson",
"Matthew Hurst"
] | [] | [] | [] |
VAST | 2,008 | Spatio-temporal aggregation for visual analysis of movements | 10.1109/VAST.2008.4677356 | Data about movements of various objects are collected in growing amounts by means of current tracking technologies. Traditional approaches to visualization and interactive exploration of movement data cannot cope with data of such sizes. In this research paper we investigate the ways of using aggregation for visual analysis of movement data. We define aggregation methods suitable for movement data and find visualization and interaction techniques to represent results of aggregations and enable comprehensive exploration of the data. We consider two possible views of movement, traffic-oriented and trajectory-oriented. Each view requires different methods of analysis and of data aggregation. We illustrate our argument with example data resulting from tracking multiple cars in Milan and example analysis tasks from the domain of city traffic management. | false | false | [
"Gennady L. Andrienko",
"Natalia V. Andrienko"
] | [] | [] | [] |
VAST | 2,008 | Supporting exploration awareness for visual analytics | 10.1109/VAST.2008.4677378 | While exploring data using information visualization, analysts try to make sense of the data, build cases, and present them to others. However, if the exploration is long or done in multiple sessions, it can be hard for analysts to remember all interesting visualizations and the relationships among them they have seen. Often, they will see the same or similar visualizations, and are unable to recall when, why and how they have seen something similar. Recalling and retrieving interesting visualizations are important tasks for the analysis processes such as problem solving, reasoning, and conceptualization. In this paper, we argue that offering support for thinking based on past analysis processes is important, and present a solution for this. | false | false | [
"Yedendra Babu Shrinivasan",
"Jarke J. van Wijk"
] | [] | [] | [] |
VAST | 2,008 | The Scalable Reasoning System: Lightweight visualization for distributed analytics | 10.1109/VAST.2008.4677366 | A central challenge in visual analytics is the creation of accessible, widely distributable analysis applications that bring the benefits of visual discovery to as broad a user base as possible. Moreover, to support the role of visualization in the knowledge creation process, it is advantageous to allow users to describe the reasoning strategies they employ while interacting with analytic environments. We introduce an application suite called the scalable reasoning system (SRS), which provides Web-based and mobile interfaces for visual analysis. The service-oriented analytic framework that underlies SRS provides a platform for deploying pervasive visual analytic environments across an enterprise. SRS represents a ldquolightweightrdquo approach to visual analytics whereby thin client analytic applications can be rapidly deployed in a platform-agnostic fashion. Client applications support multiple coordinated views while giving analysts the ability to record evidence, assumptions, hypotheses and other reasoning artifacts. We describe the capabilities of SRS in the context of a real-world deployment at a regional law enforcement organization. | false | false | [
"William A. Pike",
"Joe Bruce",
"Bob Baddeley",
"Daniel M. Best",
"Lyndsey Franklin",
"Richard May 0001",
"Douglas M. Rice",
"Roderick M. Riensche",
"Katarina Younkin"
] | [] | [] | [] |
VAST | 2,008 | Understanding syndromic hotspots - a visual analytics approach | 10.1109/VAST.2008.4677354 | When analyzing syndromic surveillance data, health care officials look for areas with unusually high cases of syndromes. Unfortunately, many outbreaks are difficult to detect because their signal is obscured by the statistical noise. Consequently, many detection algorithms have a high false positive rate. While many false alerts can be easily filtered by trained epidemiologists, others require health officials to drill down into the data, analyzing specific segments of the population and historical trends over time and space. Furthermore, the ability to accurately recognize meaningful patterns in the data becomes more challenging as these data sources increase in volume and complexity. To facilitate more accurate and efficient event detection, we have created a visual analytics tool that provides analysts with linked geo-spatiotemporal and statistical analytic views. We model syndromic hotspots by applying a kernel density estimation on the population sample. When an analyst selects a syndromic hotspot, temporal statistical graphs of the hotspot are created. Similarly, regions in the statistical plots may be selected to generate geospatial features specific to the current time period. Demographic filtering can then be combined to determine if certain populations are more affected than others. These tools allow analysts to perform real-time hypothesis testing and evaluation. | false | false | [
"Ross Maciejewski",
"Stephen Rudolph",
"Ryan Hafen",
"Ahmad M. Abusalah",
"Mohamed Yakout",
"Mourad Ouzzani",
"William S. Cleveland",
"Shaun J. Grannis",
"Michael Wade",
"David S. Ebert"
] | [] | [] | [] |
VAST | 2,008 | Using SocialAction to uncover structure in social networks over time | 10.1109/VAST.2008.4677392 | I describe how SocialAction was used to find insights in an evolving social structure VAST Challenge 2008psilas Mini-Challenge 3. This analysis and SocialAction were given the award, ldquoCell Phone Mini Challenge Award: Time Visualizations of Cell Phone Activityrdquo. | false | false | [
"Adam Perer"
] | [] | [] | [] |
VAST | 2,008 | Using visual analytics to maintain situation awareness in astrophysics | 10.1109/VAST.2008.4677353 | We present a novel collaborative visual analytics application for cognitively overloaded users in the astrophysics domain. The system was developed for scientists needing to analyze heterogeneous, complex data under time pressure, and then make predictions and time-critical decisions rapidly and correctly under a constant influx of changing data. The Sunfall Data Taking system utilizes several novel visualization and analysis techniques to enable a team of geographically distributed domain specialists to effectively and remotely maneuver a custom-built instrument under challenging operational conditions. Sunfall Data Taking has been in use for over eighteen months by a major international astrophysics collaboration (the largest data volume supernova search currently in operation), and has substantially improved the operational efficiency of its users. We describe the system design process by an interdisciplinary team, the system architecture, and the results of an informal usability evaluation of the production system by domain experts in the context of Endsleypsilas three levels of situation awareness. | false | false | [
"Cecilia R. Aragon",
"Sarah S. Poon",
"Gregory S. Aldering",
"Rollin C. Thomas",
"Robert Quimby"
] | [] | [] | [] |
VAST | 2,008 | VAST 2008 Challenge: Introducing mini-challenges | 10.1109/VAST.2008.4677383 | Visual analytics experts realize that one effective way to push the field forward and to develop metrics for measuring the performance of various visual analytics components is to hold an annual competition. The VAST 2008 Challenge is the third year that such a competition was held in conjunction with the IEEE Visual Analytics Science and Technology (VAST) symposium. The authors restructured the contest format used in 2006 and 2007 to reduce the barriers to participation and offered four mini-challenges and a Grand Challenge. Mini Challenge participants were to use visual analytic tools to explore one of four heterogeneous data collections to analyze specific activities of a fictitious, controversial movement. Questions asked in the Grand Challenge required the participants to synthesize data from all four data sets. In this paper we give a brief overview of the data sets, the tasks, the participation, the judging, and the results. | false | false | [
"Georges G. Grinstein",
"Catherine Plaisant",
"Sharon J. Laskowski",
"Teresa O'Connell",
"Jean Scholtz",
"Mark A. Whiting"
] | [] | [] | [] |
VAST | 2,008 | Visual analysis for mutual fund performance | 10.1109/VAST.2008.4677376 | Mutual funds are one of the most important investment instruments available. However, choosing among mutual funds is not an easy task because they vary in many different dimensions, such as asset size, turnover and fee structure, and these characteristics may affect fund returns. It is thus important to understand the relation between fund performance and these properties. In this work, we use a new visual analytical tool, the density-based distribution map, to assist in this task. By visualizing various important fund characteristics from a real-world database of the US stock funds, our new visual representations greatly help understand the relation between fund characteristics and returns. | false | false | [
"Ye Zhao 0003",
"Jamal Alsakran",
"Xinlei Zhao"
] | [] | [] | [] |
VAST | 2,008 | Visual analysis of seismic simulation data | 10.1109/VAST.2008.4677381 | Seismic simulations use finite element methods to describe ground motion. The results of such numerical simulations are often difficult to interpret for decision makers. We describe a terrain rendering engine that uses photorealistic metaphors to represent typical terrain properties without representing an actual terrain. In the context of ground motion, a simulation of the effects of various types of earthquakes on buildings has been conducted. Usually, such structural response simulations are carried out independently and are being visualized separate from the ground motion simulation. We combine the results from both simulations in an interactive, hybrid visualization so that decision makers (first responders and emergency management agencies) are provided with a photo-realistic, simulated view of various earthquake scenarios, enabling them to study the effect of various earthquakes on buildings typical for a rural or urban area. We present a method for visually analyzing large-scale simulation data from different sources (ground motion simulation and structural response simulation) using photorealistic metaphors. We have implemented an intuitive, interactive system for visual analysis and inspection of possible effects of various types of earthquakes on an inventory of buildings typical for a particular area. The underlying rendering system can be easily adapted for other simulations, such as smoke plumes or biohazards. | false | false | [
"Florian Jürgen Gerhardt",
"Jörg Meyer 0002"
] | [] | [] | [] |
VAST | 2,008 | Visual analytics for complex concepts using a human cognition model | 10.1109/VAST.2008.4677361 | As the information being visualized and the process of understanding that information both become increasingly complex, it is necessary to develop new visualization approaches that facilitate the flow of human reasoning. In this paper, we endeavor to push visualization design a step beyond current user models by discussing a modeling framework of human ldquohigher cognition.rdquo Based on this cognition model, we present design guidelines for the development of visual interfaces designed to maximize the complementary cognitive strengths of both human and computer. Some of these principles are already being reflected in the better visual analytics designs, while others have not yet been applied or fully applied. But none of the guidelines have explained the deeper rationale that the model provides. Lastly, we discuss and assess these visual analytics guidelines through the evaluation of several visualization examples. | false | false | [
"Tera Marie Green",
"William Ribarsky",
"Brian D. Fisher"
] | [] | [] | [] |
VAST | 2,008 | Visual cluster analysis of trajectory data with interactive Kohonen Maps | 10.1109/VAST.2008.4677350 | Visual-interactive cluster analysis provides valuable tools for effectively analyzing large and complex data sets. Due to desirable properties and an inherent predisposition for visualization, the Kohonen Feature Map (or self-organizing map, or SOM) algorithm is among the most popular and widely used visual clustering techniques. However, the unsupervised nature of the algorithm may be disadvantageous in certain applications. Depending on initialization and data characteristics, cluster maps (cluster layouts) may emerge that do not comply with user preferences, expectations, or the application context. Considering SOM-based analysis of trajectory data, we propose a comprehensive visual-interactive monitoring and control framework extending the basic SOM algorithm. The framework implements the general Visual Analytics idea to effectively combine automatic data analysis with human expert supervision. It provides simple, yet effective facilities for visually monitoring and interactively controlling the trajectory clustering process at arbitrary levels of detail. The approach allows the user to leverage existing domain knowledge and user preferences, arriving at improved cluster maps. We apply the framework on a trajectory clustering problem, demonstrating its potential in combining both unsupervised (machine) and supervised (human expert) processing, in producing appropriate cluster results. | false | false | [
"Tobias Schreck",
"Jürgen Bernard",
"Tatiana von Landesberger",
"Jörn Kohlhammer"
] | [] | [] | [] |
VAST | 2,008 | Visual evaluation of text features for document summarization and analysis | 10.1109/VAST.2008.4677359 | Thanks to the Web-related and other advanced technologies, textual information is increasingly being stored in digital form and posted online. Automatic methods to analyze such textual information are becoming inevitable. Many of those methods are based on quantitative text features. Analysts face the challenge to choose the most appropriate features for their tasks. This requires effective approaches for evaluation and feature-engineering. | false | false | [
"Daniela Oelke",
"Peter Bak",
"Daniel A. Keim",
"Mark Last",
"Guy Danon"
] | [] | [] | [] |
VAST | 2,008 | Visual mining of multimedia data for social and behavioral studies | 10.1109/VAST.2008.4677369 | With advances in computing techniques, a large amount of high-resolution high-quality multimedia data (video and audio, etc.) has been collected in research laboratories in various scientific disciplines, particularly in social and behavioral studies. How to automatically and effectively discover new knowledge from rich multimedia data poses a compelling challenge since state-of-the-art data mining techniques can most often only search and extract pre-defined patterns or knowledge from complex heterogeneous data. In light of this, our approach is to take advantages of both the power of human perception system and the power of computational algorithms. More specifically, we propose an approach that allows scientists to use data mining as a first pass, and then forms a closed loop of visual analysis of current results followed by more data mining work inspired by visualization, the results of which can be in turn visualized and lead to the next round of visual exploration and analysis. In this way, new insights and hypotheses gleaned from the raw data and the current level of analysis can contribute to further analysis. As a first step toward this goal, we implement a visualization system with three critical components: (1) A smooth interface between visualization and data mining. The new analysis results can be automatically loaded into our visualization tool. (2) A flexible tool to explore and query temporal data derived from raw multimedia data. We represent temporal data into two forms - continuous variables and event variables. We have developed various ways to visualize both temporal correlations and statistics of multiple variables with the same type, and conditional and high-order statistics between continuous and event variables. (3) A seamless interface between raw multimedia data and derived data. Our visualization tool allows users to explore, compare, and analyze multi-stream derived variables and simultaneously switch to access raw multimedia data. We demonstrate various functions in our visualization program using a set of multimedia data including video, audio and motion tracking data. | false | false | [
"Chen Yu 0001",
"Yiwen Zhong",
"Thomas G. Smith",
"Ikhyun Park",
"Weixia Huang"
] | [] | [] | [] |
InfoVis | 2,008 | A Framework of Interaction Costs in Information Visualization | 10.1109/TVCG.2008.109 | Interaction cost is an important but poorly understood factor in visualization design. We propose a framework of interaction costs inspired by Normanpsilas Seven Stages of Action to facilitate study. From 484 papers, we collected 61 interaction-related usability problems reported in 32 user studies and placed them into our framework of seven costs: (1) Decision costs to form goals; (2) system-power costs to form system operations; (3) Multiple input mode costs to form physical sequences; (4) Physical-motion costs to execute sequences; (5) Visual-cluttering costs to perceive state; (6) View-change costs to interpret perception; (7) State-change costs to evaluate interpretation. We also suggested ways to narrow the gulfs of execution (2-4) and evaluation (5-7) based on collected reports. Our framework suggests a need to consider decision costs (1) as the gulf of goal formation. | false | false | [
"Heidi Lam"
] | [
"HM"
] | [] | [] |
InfoVis | 2,008 | Balloon Focus: a Seamless Multi-Focus+Context Method for Treemaps | 10.1109/TVCG.2008.114 | The treemap is one of the most popular methods for visualizing hierarchical data. When a treemap contains a large number of items, inspecting or comparing a few selected items in a greater level of detail becomes very challenging. In this paper, we present a seamless multi-focus and context technique, called Balloon Focus, that allows the user to smoothly enlarge multiple treemap items served as the foci, while maintaining a stable treemap layout as the context. Our method has several desirable features. First, this method is quite general and can be used with different treemap layout algorithms. Second, as the foci are enlarged, the relative positions among all items are preserved. Third, the foci are placed in a way that the remaining space is evenly distributed back to the non-focus treemap items. When Balloon Focus enlarges the focus items to a maximum degree, the above features ensure that the treemap will maintain a consistent appearance and avoid any abrupt layout changes. In our algorithm, a DAG (Directed Acyclic Graph) is used to maintain the positional constraints, and an elastic model is employed to govern the placement of the treemap items. We demonstrate a treemap visualization system that integrates data query, manual focus selection, and our novel multi-focus+context technique, Balloon Focus, together. A user study was conducted. Results show that with Balloon Focus, users can better perform the tasks of comparing the values and the distribution of the foci. | false | false | [
"Ying Tu",
"Han-Wei Shen"
] | [] | [] | [] |
InfoVis | 2,008 | Cerebral: Visualizing Multiple Experimental Conditions on a Graph with Biological Context | 10.1109/TVCG.2008.117 | Systems biologists use interaction graphs to model the behavior of biological systems at the molecular level. In an iterative process, such biologists observe the reactions of living cells under various experimental conditions, view the results in the context of the interaction graph, and then propose changes to the graph model. These graphs serve as a form of dynamic knowledge representation of the biological system being studied and evolve as new insight is gained from the experimental data. While numerous graph layout and drawing packages are available, these tools did not fully meet the needs of our immunologist collaborators. In this paper, we describe the data information display needs of these immunologists and translate them into design decisions. These decisions led us to create Cerebral, a system that uses a biologically guided graph layout and incorporates experimental data directly into the graph display. Small multiple views of different experimental conditions and a data-driven parallel coordinates view enable correlations between experimental conditions to be analyzed at the same time that the data is viewed in the graph context. This combination of coordinated views allows the biologist to view the data from many different perspectives simultaneously. To illustrate the typical analysis tasks performed, we analyze two datasets using Cerebral. Based on feedback from our collaborators we conclude that Cerebral is a valuable tool for analyzing experimental data in the context of an interaction graph model. | false | false | [
"Aaron Barsky",
"Tamara Munzner",
"Jennifer L. Gardy",
"Robert Kincaid"
] | [] | [] | [] |
InfoVis | 2,008 | Distributed Cognition as a Theoretical Framework for Information Visualization | 10.1109/TVCG.2008.121 | Even though information visualization (InfoVis) research has matured in recent years, it is generally acknowledged that the field still lacks supporting, encompassing theories. In this paper, we argue that the distributed cognition framework can be used to substantiate the theoretical foundation of InfoVis. We highlight fundamental assumptions and theoretical constructs of the distributed cognition approach, based on the cognitive science literature and a real life scenario. We then discuss how the distributed cognition framework can have an impact on the research directions and methodologies we take as InfoVis researchers. Our contributions are as follows. First, we highlight the view that cognition is more an emergent property of interaction than a property of the human mind. Second, we argue that a reductionist approach to study the abstract properties of isolated human minds may not be useful in informing InfoVis design. Finally we propose to make cognition an explicit research agenda, and discuss the implications on how we perform evaluation and theory building. | false | false | [
"Zhicheng Liu",
"Nancy J. Nersessian",
"John T. Stasko"
] | [] | [] | [] |
InfoVis | 2,008 | Effectiveness of Animation in Trend Visualization | 10.1109/TVCG.2008.125 | Animation has been used to show trends in multi-dimensional data. This technique has recently gained new prominence for presentations, most notably with Gapminder Trendalyzer. In Trendalyzer, animation together with interesting data and an engaging presenter helps the audience understand the results of an analysis of the data. It is less clear whether trend animation is effective for analysis. This paper proposes two alternative trend visualizations that use static depictions of trends: one which shows traces of all trends overlaid simultaneously in one display and a second that uses a small multiples display to show the trend traces side-by-side. The paper evaluates the three visualizations for both analysis and presentation. Results indicate that trend animation can be challenging to use even for presentations; while it is the fastest technique for presentation and participants find it enjoyable and exciting, it does lead to many participant errors. Animation is the least effective form for analysis; both static depictions of trends are significantly faster than animation, and the small multiples display is more accurate. | false | false | [
"George G. Robertson",
"Roland Fernandez",
"Danyel Fisher",
"Bongshin Lee",
"John T. Stasko"
] | [
"TT"
] | [] | [] |
InfoVis | 2,008 | EMDialog: Bringing Information Visualization into the Museum | 10.1109/TVCG.2008.127 | 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 exploration environment that offers 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. | false | false | [
"Uta Hinrichs",
"Holly Schmidt",
"Sheelagh Carpendale"
] | [] | [] | [] |
InfoVis | 2,008 | Evaluating the Use of Data Transformation for Information Visualization | 10.1109/TVCG.2008.129 | Data transformation, the process of preparing raw data for effective visualization, is one of the key challenges in information visualization. Although researchers have developed many data transformation techniques, there is little empirical study of the general impact of data transformation on visualization. Without such study, it is difficult to systematically decide when and which data transformation techniques are needed. We thus have designed and conducted a two-part empirical study that examines how the use of common data transformation techniques impacts visualization quality, which in turn affects user task performance. Our first experiment studies the impact of data transformation on user performance in single-step, typical visual analytic tasks. The second experiment assesses the impact of data transformation in multi-step analytic tasks. Our results quantify the benefits of data transformation in both experiments. More importantly, our analyses reveal that (1) the benefits of data transformation vary significantly by task and by visualization, and (2) the use of data transformation depends on a user's interaction context. Based on our findings, we present a set of design recommendations that help guide the development and use of data transformation techniques. | false | false | [
"Zhen Wen",
"Michelle X. Zhou"
] | [] | [] | [] |
InfoVis | 2,008 | Exploration of Networks using overview+detail with Constraint-based cooperative layout | 10.1109/TVCG.2008.130 | A standard approach to large network visualization is to provide an overview of the network and a detailed view of a small component of the graph centred around a focal node. The user explores the network by changing the focal node in the detailed view or by changing the level of detail of a node or cluster. For scalability, fast force-based layout algorithms are used for the overview and the detailed view. However, using the same layout algorithm in both views is problematic since layout for the detailed view has different requirements to that in the overview. Here we present a model in which constrained graph layout algorithms are used for layout in the detailed view. This means the detailed view has high-quality layout including sophisticated edge routing and is customisable by the user who can add placement constraints on the layout. Scalability is still ensured since the slower layout techniques are only applied to the small subgraph shown in the detailed view. The main technical innovations are techniques to ensure that the overview and detailed view remain synchronized, and modifying constrained graph layout algorithms to support smooth, stable layout. The key innovation supporting stability are new dynamic graph layout algorithms that preserve the topology or structure of the network when the user changes the focus node or the level of detail by in situ semantic zooming. We have built a prototype tool and demonstrate its use in two application domains, UML class diagrams and biological networks. | false | false | [
"Tim Dwyer",
"Kim Marriott",
"Falk Schreiber",
"Peter J. Stuckey",
"Michael Woodward",
"Michael Wybrow"
] | [] | [] | [] |
InfoVis | 2,008 | Geometry-Based Edge Clustering for Graph Visualization | 10.1109/TVCG.2008.135 | Graphs have been widely used to model relationships among data. For large graphs, excessive edge crossings make the display visually cluttered and thus difficult to explore. In this paper, we propose a novel geometry-based edge-clustering framework that can group edges into bundles to reduce the overall edge crossings. Our method uses a control mesh to guide the edge-clustering process; edge bundles can be formed by forcing all edges to pass through some control points on the mesh. The control mesh can be generated at different levels of detail either manually or automatically based on underlying graph patterns. Users can further interact with the edge-clustering results through several advanced visualization techniques such as color and opacity enhancement. Compared with other edge-clustering methods, our approach is intuitive, flexible, and efficient. The experiments on some large graphs demonstrate the effectiveness of our method. | false | false | [
"Weiwei Cui",
"Hong Zhou 0004",
"Huamin Qu",
"Pak Chung Wong",
"Xiaoming Li 0001"
] | [] | [] | [] |
InfoVis | 2,008 | Graphical Histories for Visualization: Supporting Analysis, Communication, and Evaluation | 10.1109/TVCG.2008.137 | Interactive history tools, ranging from basic undo and redo to branching timelines of user actions, facilitate iterative forms of interaction. In this paper, we investigate the design of history mechanisms for information visualization. We present a design space analysis of both architectural and interface issues, identifying design decisions and associated trade-offs. Based on this analysis, we contribute a design study of graphical history tools for Tableau, a database visualization system. These tools record and visualize interaction histories, support data analysis and communication of findings, and contribute novel mechanisms for presenting, managing, and exporting histories. Furthermore, we have analyzed aggregated collections of history sessions to evaluate Tableau usage. We describe additional tools for analyzing userspsila history logs and how they have been applied to study usage patterns in Tableau. | false | false | [
"Jeffrey Heer",
"Jock D. Mackinlay",
"Chris Stolte",
"Maneesh Agrawala"
] | [] | [] | [] |
InfoVis | 2,008 | HiPP: A Novel Hierarchical Point Placement Strategy and its Application to the Exploration of Document Collections | 10.1109/TVCG.2008.138 | Point placement strategies aim at mapping data points represented in higher dimensions to bi-dimensional spaces and are frequently used to visualize relationships amongst data instances. They have been valuable tools for analysis and exploration of data sets of various kinds. Many conventional techniques, however, do not behave well when the number of dimensions is high, such as in the case of documents collections. Later approaches handle that shortcoming, but may cause too much clutter to allow flexible exploration to take place. In this work we present a novel hierarchical point placement technique that is capable of dealing with these problems. While good grouping and separation of data with high similarity is maintained without increasing computation cost, its hierarchical structure lends itself both to exploration in various levels of detail and to handling data in subsets, improving analysis capability and also allowing manipulation of larger data sets. | false | false | [
"Fernando Vieira Paulovich",
"Rosane Minghim"
] | [] | [] | [] |
InfoVis | 2,008 | Improving the Readability of Clustered Social Networks using Node Duplication | 10.1109/TVCG.2008.141 | Exploring communities is an important task in social network analysis. Such communities are currently identified using clustering methods to group actors. This approach often leads to actors belonging to one and only one cluster, whereas in real life a person can belong to several communities. As a solution we propose duplicating actors in social networks and discuss potential impact of such a move. Several visual duplication designs are discussed and a controlled experiment comparing network visualization with and without duplication is performed, using 6 tasks that are important for graph readability and visual interpretation of social networks. We show that in our experiment, duplications significantly improve community-related tasks but sometimes interfere with other graph readability tasks. Finally, we propose a set of guidelines for deciding when to duplicate actors and choosing candidates for duplication, and alternative ways to render them in social network representations. | false | false | [
"Nathalie Henry Riche",
"Anastasia Bezerianos",
"Jean-Daniel Fekete"
] | [] | [] | [] |
InfoVis | 2,008 | Interactive Visual Analysis of Set-Typed Data | 10.1109/TVCG.2008.144 | While it is quite typical to deal with attributes of different data types in the visualization of heterogeneous and multivariate datasets, most existing techniques still focus on the most usual data types such as numerical attributes or strings. In this paper we present a new approach to the interactive visual exploration and analysis of data that contains attributes which are of set type. A set-typed attribute of a data item - like one cell in a table - has a list of nGt=0 elements as its value. We present the setpsilaopsilagram as a new visualization approach to represent data of set type and to enable interactive visual exploration and analysis. We also demonstrate how this approach is capable to help in dealing with datasets that have a larger number of dimensions (more than a dozen or more), especially also in the context of categorical data. To illustrate the effectiveness of our approach, we present the interactive visual analysis of a CRM dataset with data from a questionnaire on the education and shopping habits of about 90000 people. | false | false | [
"Wolfgang Freiler",
"Kresimir Matkovic",
"Helwig Hauser"
] | [] | [] | [] |
InfoVis | 2,008 | Multi-Focused Geospatial Analysis Using Probes | 10.1109/TVCG.2008.149 | Traditional geospatial information visualizations often present views that restrict the user to a single perspective. When zoomed out, local trends and anomalies become suppressed and lost; when zoomed in for local inspection, spatial awareness and comparison between regions become limited. In our model, coordinated visualizations are integrated within individual probe interfaces, which depict the local data in user-defined regions-of-interest. Our probe concept can be incorporated into a variety of geospatial visualizations to empower users with the ability to observe, coordinate, and compare data across multiple local regions. It is especially useful when dealing with complex simulations or analyses where behavior in various localities differs from other localities and from the system as a whole. We illustrate the effectiveness of our technique over traditional interfaces by incorporating it within three existing geospatial visualization systems: an agent-based social simulation, a census data exploration tool, and an 3D GIS environment for analyzing urban change over time. In each case, the probe-based interaction enhances spatial awareness, improves inspection and comparison capabilities, expands the range of scopes, and facilitates collaboration among multiple users. | false | false | [
"Thomas Butkiewicz",
"Wenwen Dou",
"Zachary Wartell",
"William Ribarsky",
"Remco Chang"
] | [] | [] | [] |
InfoVis | 2,008 | On the Visualization of Social and other Scale-Free Networks | 10.1109/TVCG.2008.151 | This paper proposes novel methods for visualizing specifically the large power-law graphs that arise in sociology and the sciences. In such cases a large portion of edges can be shown to be less important and removed while preserving component connectedness and other features (e.g. cliques) to more clearly reveal the networkpsilas underlying connection pathways. This simplification approach deterministically filters (instead of clustering) the graph to retain important node and edge semantics, and works both automatically and interactively. The improved graph filtering and layout is combined with a novel computer graphics anisotropic shading of the dense crisscrossing array of edges to yield a full social network and scale-free graph visualization system. Both quantitative analysis and visual results demonstrate the effectiveness of this approach. | false | false | [
"Yuntao Jia",
"Jared Hoberock",
"Michael Garland",
"John C. Hart"
] | [] | [] | [] |
InfoVis | 2,008 | Particle-based labeling: Fast point-feature labeling without obscuring other visual features | 10.1109/TVCG.2008.152 | In many information visualization techniques, labels are an essential part to communicate the visualized data. To preserve the expressiveness of the visual representation, a placed label should neither occlude other labels nor visual representatives (e.g., icons, lines) that communicate crucial information. Optimal, non-overlapping labeling is an NP-hard problem. Thus, only a few approaches achieve a fast non-overlapping labeling in highly interactive scenarios like information visualization. These approaches generally target the point-feature label placement (PFLP) problem, solving only label-label conflicts. This paper presents a new, fast, solid and flexible 2D labeling approach for the PFLP problem that additionally respects other visual elements and the visual extent of labeled features. The results (number of placed labels, processing time) of our particle-based method compare favorably to those of existing techniques. Although the esthetic quality of non-real-time approaches may not be achieved with our method, it complies with practical demands and thus supports the interactive exploration of information spaces. In contrast to the known adjacent techniques, the flexibility of our technique enables labeling of dense point clouds by the use of non-occluding distant labels. Our approach is independent of the underlying visualization technique, which enables us to demonstrate the application of our labeling method within different information visualization scenarios. | false | false | [
"Martin Luboschik",
"Heidrun Schumann",
"Hilko Cords"
] | [] | [] | [] |
InfoVis | 2,008 | Perceptual Organization in User-Generated Graph Layouts | 10.1109/TVCG.2008.155 | Many graph layout algorithms optimize visual characteristics to achieve useful representations. Implicitly, their goal is to create visual representations that are more intuitive to human observers. In this paper, we asked users to explicitly manipulate nodes in a network diagram to create layouts that they felt best captured the relationships in the data. This allowed us to measure organizational behavior directly, allowing us to evaluate the perceptual importance of particular visual features, such as edge crossings and edge-lengths uniformity. We also manipulated the interior structure of the node relationships by designing data sets that contained clusters, that is, sets of nodes that are strongly interconnected. By varying the degree to which these clusters were ldquomaskedrdquo by extraneous edges we were able to measure observerspsila sensitivity to the existence of clusters and how they revealed them in the network diagram. Based on these measurements we found that observers are able to recover cluster structure, that the distance between clusters is inversely related to the strength of the clustering, and that users exhibit the tendency to use edges to visually delineate perceptual groups. These results demonstrate the role of perceptual organization in representing graph data and provide concrete recommendations for graph layout algorithms. | false | false | [
"Frank van Ham",
"Bernice E. Rogowitz"
] | [] | [] | [] |
InfoVis | 2,008 | Rapid Graph Layout Using Space filling Curves | 10.1109/TVCG.2008.158 | Network data frequently arises in a wide variety of fields, and node-link diagrams are a very natural and intuitive representation of such data. In order for a node-link diagram to be effective, the nodes must be arranged well on the screen. While many graph layout algorithms exist for this purpose, they often have limitations such as high computational complexity or node colocation. This paper proposes a new approach to graph layout through the use of space filling curves which is very fast and guarantees that there will be no nodes that are colocated. The resulting layout is also aesthetic and satisfies several criteria for graph layout effectiveness. | false | false | [
"Chris Muelder",
"Kwan-Liu Ma"
] | [] | [] | [] |
InfoVis | 2,008 | Rolling the Dice: Multidimensional Visual Exploration using Scatterplot Matrix Navigation | 10.1109/TVCG.2008.153 | Scatterplots remain one of the most popular and widely-used visual representations for multidimensional data due to their simplicity, familiarity and visual clarity, even if they lack some of the flexibility and visual expressiveness of newer multidimensional visualization techniques. This paper presents new interactive methods to explore multidimensional data using scatterplots. This exploration is performed using a matrix of scatterplots that gives an overview of the possible configurations, thumbnails of the scatterplots, and support for interactive navigation in the multidimensional space. Transitions between scatterplots are performed as animated rotations in 3D space, somewhat akin to rolling dice. Users can iteratively build queries using bounding volumes in the dataset, sculpting the query from different viewpoints to become more and more refined. Furthermore, the dimensions in the navigation space can be reordered, manually or automatically, to highlight salient correlations and differences among them. An example scenario presents the interaction techniques supporting smooth and effortless visual exploration of multidimensional datasets. | false | false | [
"Niklas Elmqvist",
"Pierre Dragicevic",
"Jean-Daniel Fekete"
] | [
"BP"
] | [] | [] |
InfoVis | 2,008 | Spatially Ordered Treemaps | 10.1109/TVCG.2008.165 | Existing treemap layout algorithms suffer to some extent from poor or inconsistent mappings between data order and visual ordering in their representation, reducing their cognitive plausibility. While attempts have been made to quantify this mismatch, and algorithms proposed to minimize inconsistency, solutions provided tend to concentrate on one-dimensional ordering. We propose extensions to the existing squarified layout algorithm that exploit the two-dimensional arrangement of treemap nodes more effectively. Our proposed spatial squarified layout algorithm provides a more consistent arrangement of nodes while maintaining low aspect ratios. It is suitable for the arrangement of data with a geographic component and can be used to create tessellated cartograms for geovisualization. Locational consistency is measured and visualized and a number of layout algorithms are compared. CIELab color space and displacement vector overlays are used to assess and emphasize the spatial layout of treemap nodes. A case study involving locations of tagged photographs in the Flickr database is described. | false | false | [
"Jo Wood",
"Jason Dykes"
] | [] | [] | [] |
InfoVis | 2,008 | Stacked Graphs - Geometry & Aesthetics | 10.1109/TVCG.2008.166 | In February 2008, the New York Times published an unusual chart of box office revenues for 7500 movies over 21 years. The chart was based on a similar visualization, developed by the first author, that displayed trends in music listening. This paper describes the design decisions and algorithms behind these graphics, and discusses the reaction on the Web. We suggest that this type of complex layered graph is effective for displaying large data sets to a mass audience. We provide a mathematical analysis of how this layered graph relates to traditional stacked graphs and to techniques such as ThemeRiver, showing how each method is optimizing a different ldquoenergy functionrdquo. Finally, we discuss techniques for coloring and ordering the layers of such graphs. Throughout the paper, we emphasize the interplay between considerations of aesthetics and legibility. | false | false | [
"Lee Byron",
"Martin Wattenberg"
] | [
"HM"
] | [] | [] |
InfoVis | 2,008 | The Shaping of Information by Visual Metaphors | 10.1109/TVCG.2008.171 | The nature of an information visualization can be considered to lie in the visual metaphors it uses to structure information. The process of understanding a visualization therefore involves an interaction between these external visual metaphors and the user's internal knowledge representations. To investigate this claim, we conducted an experiment to test the effects of visual metaphor and verbal metaphor on the understanding of tree visualizations. Participants answered simple data comprehension questions while viewing either a treemap or a node-link diagram. Questions were worded to reflect a verbal metaphor that was either compatible or incompatible with the visualization a participant was using. The results suggest that the visual metaphor indeed affects how a user derives information from a visualization. Additionally, we found that the degree to which a user is affected by the metaphor is strongly correlated with the user's ability to answer task questions correctly. These findings are a first step towards illuminating how visual metaphors shape user understanding, and have significant implications for the evaluation, application, and theory of visualization. | false | false | [
"Caroline Ziemkiewicz",
"Robert Kosara"
] | [
"HM"
] | [] | [] |
InfoVis | 2,008 | The Word Tree, an Interactive Visual Concordance | 10.1109/TVCG.2008.172 | We introduce the Word Tree, a new visualization and information-retrieval technique aimed at text documents. A Word Tree is a graphical version of the traditional "keyword-in-context" method, and enables rapid querying and exploration of bodies of text. In this paper we describe the design of the technique, along with some of the technical issues that arise in its implementation. In addition, we discuss the results of several months of public deployment of word trees on Many Eyes, which provides a window onto the ways in which users obtain value from the visualization. | false | false | [
"Martin Wattenberg",
"Fernanda B. Viégas"
] | [] | [] | [] |
InfoVis | 2,008 | VisGets: Coordinated Visualizations for Web-based Information Exploration and Discovery | 10.1109/TVCG.2008.175 | 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. | false | false | [
"Marian Dörk",
"Sheelagh Carpendale",
"Christopher Collins 0001",
"Carey L. Williamson"
] | [] | [] | [] |
InfoVis | 2,008 | Vispedia: Interactive Visual Exploration of Wikipedia Data via Search-Based Integration | 10.1109/TVCG.2008.178 | Wikipedia is an example of the collaborative, semi-structured data sets emerging on the Web. These data sets have large, non-uniform schema that require costly data integration into structured tables before visualization can begin. We present Vispedia, a Web-based visualization system that reduces the cost of this data integration. Users can browse Wikipedia, select an interesting data table, then use a search interface to discover, integrate, and visualize additional columns of data drawn from multiple Wikipedia articles. This interaction is supported by a fast path search algorithm over DBpedia, a semantic graph extracted from Wikipedia's hyperlink structure. Vispedia can also export the augmented data tables produced for use in traditional visualization systems. We believe that these techniques begin to address the "long tail" of visualization by allowing a wider audience to visualize a broader class of data. We evaluated this system in a first-use formative lab study. Study participants were able to quickly create effective visualizations for a diverse set of domains, performing data integration as needed. | false | false | [
"Bryan Chan 0001",
"Leslie Wu",
"Justin Talbot",
"Mike Cammarano",
"Pat Hanrahan"
] | [] | [] | [] |
InfoVis | 2,008 | Visualizing Incomplete and Partially Ranked Data | 10.1109/TVCG.2008.181 | Ranking data, which result from m raters ranking n items, are difficult to visualize due to their discrete algebraic structure, and the computational difficulties associated with them when n is large. This problem becomes worse when raters provide tied rankings or not all items are ranked. We develop an approach for the visualization of ranking data for large n which is intuitive, easy to use, and computationally efficient. The approach overcomes the structural and computational difficulties by utilizing a natural measure of dissimilarity for raters, and projecting the raters into a low dimensional vector space where they are viewed. The visualization techniques are demonstrated using voting data, jokes, and movie preferences. | false | false | [
"Paul Kidwell",
"Guy Lebanon",
"William S. Cleveland"
] | [] | [] | [] |
InfoVis | 2,008 | Viz-A-Vis: Toward Visualizing Video through Computer Vision | 10.1109/TVCG.2008.185 | In the established procedural model of information visualization, the first operation is to transform raw data into data tables. The transforms typically include abstractions that aggregate and segment relevant data and are usually defined by a human, user or programmer. The theme of this paper is that for video, data transforms should be supported by low level computer vision. High level reasoning still resides in the human analyst, while part of the low level perception is handled by the computer. To illustrate this approach, we present Viz-A-Vis, an overhead video capture and access system for activity analysis in natural settings over variable periods of time. Overhead video provides rich opportunities for long-term behavioral and occupancy analysis, but it poses considerable challenges. We present initial steps addressing two challenges. First, overhead video generates overwhelmingly large volumes of video impractical to analyze manually. Second, automatic video analysis remains an open problem for computer vision. | false | false | [
"Mario Romero",
"Jay Summet",
"John T. Stasko",
"Gregory D. Abowd"
] | [] | [] | [] |
InfoVis | 2,008 | Who Votes For What? A Visual Query Language for Opinion Data | 10.1109/TVCG.2008.187 | Surveys and opinion polls are extremely popular in the media, especially in the months preceding a general election. However, the available tools for analyzing poll results often require specialized training. Hence, data analysis remains out of reach for many casual computer users. Moreover, the visualizations used to communicate the results of surveys are typically limited to traditional statistical graphics like bar graphs and pie charts, both of which are fundamentally noninteractive. We present a simple interactive visualization that allows users to construct queries on large tabular data sets, and view the results in real time. The results of two separate user studies suggest that our interface lowers the learning curve for naive users, while still providing enough analytical power to discover interesting correlations in the data. | false | false | [
"Geoffrey M. Draper",
"Richard F. Riesenfeld"
] | [] | [] | [] |
EuroVis | 2,008 | A Four-level Focus+Context Approach to Interactive Visual Analysis of Temporal Features in Large Scientific Data | 10.1111/j.1467-8659.2008.01207.x | In this paper we present a new approach to the interactive visual analysis of time‐dependent scientific data – both from measurements as well as from computational simulation – by visualizing a scalar function over time for each of tenthousands or even millions of sample points. In order to cope with overdrawing and cluttering, we introduce a new four‐level method of focus+context visualization. Based on a setting of coordinated, multiple views (with linking and brushing), we integrate three different kinds of focus and also the context in every single view. Per data item we use three values (from the unit interval each) to represent to which degree the data item is part of the respective focus level. We present a color compositing scheme which is capable of expressing all three values in a meaningful way, taking semantics and their relations amongst each other (in the context of our multiple linked view setup) into account. Furthermore, we present additional image‐based postprocessing methods to enhance the visualization of large sets of function graphs, including a texture‐based technique based on line integral convolution (LIC). We also propose advanced brushing techniques which are specific to the time‐dependent nature of the data (in order to brush patterns over time more efficiently). We demonstrate the usefulness of the new approach in the context of medical perfusion data. | false | false | [
"Philipp Muigg",
"Johannes Kehrer",
"Steffen Oeltze",
"Harald Piringer",
"Helmut Doleisch",
"Bernhard Preim",
"Helwig Hauser"
] | [] | [] | [] |
EuroVis | 2,008 | A Screen Space Quality Method for Data Abstraction | 10.1111/j.1467-8659.2008.01240.x | The rendering of large data sets can result in cluttered displays and non‐interactive update rates, leading to time consuming analyses. A straightforward solution is to reduce the number of items, thereby producing an abstraction of the data set. For the visual analysis to remain accurate, the graphical representation of the abstraction must preserve the significant features present in the original data. This paper presents a screen space quality method, based on distance transforms, that measures the visual quality of a data abstraction. This screen space measure is shown to better capture significant visual structures in data, compared with data space measures. The presented method is implemented on the GPU, allowing interactive creation of high quality graphical representations of multivariate data sets containing tens of thousands of items. | false | false | [
"Jimmy Johansson 0001",
"Matthew Cooper 0001"
] | [] | [] | [] |
EuroVis | 2,008 | Abstractive Representation and Exploration of Hierarchically Clustered Diffusion Tensor Fiber Tracts | 10.1111/j.1467-8659.2008.01244.x | Diffusion tensor imaging (DTI) has been used to generate fibrous structures in both brain white matter and muscles. Fiber clustering groups the DTI fibers into spatially and anatomically related tracts. As an increasing number of fiber clustering methods have been recently developed, it is important to display, compare, and explore the clustering results efficiently and effectively. In this paper, we present an anatomical visualization technique that reduces the geometric complexity of the fiber tracts and emphasizes the high‐level structures. Beginning with a volumetric diffusion tensor image, we first construct a hierarchical clustering representation of the fiber bundles. These bundles are then reformulated into a 3D multi‐valued volume data. We then build a set of geometric hulls and principal fibers to approximate the shape and orientation of each fiber bundle. By simultaneously visualizing the geometric hulls, individual fibers, and other data sets such as fractional anisotropy, the overall shape of the fiber tracts are highlighted, while preserving the fibrous details. A rater with expert knowledge of white matter structure has evaluated the resulting interactive illustration and confirmed the improvement over straightforward DTI fiber tract visualization. | false | false | [
"Wei Chen 0001",
"Song Zhang 0004",
"Stephen Correia",
"David S. Ebert"
] | [] | [] | [] |
EuroVis | 2,008 | Animating Causal Overlays | 10.1111/j.1467-8659.2008.01204.x | Most approaches to representing causality, such as the common causal graph, require a separate and static view, but in many cases it is useful to add the dimension of causality to the context of an existing visualization. Building on research from perceptual psychology that shows the perception of causality is a low‐level visual event derived from certain types of motion, we are investigating how to add animated causal representations, called visual causal vectors, onto other visualizations. We refer to these as causal overlays. Our initial experimental results show this approach has great potential but that extra cues are needed to elicit the perception of causality when the motions are overlaid on other graphical objects. In this paper we describe the approach and report on a study that examined two issues of this technique: how to accurately convey the causal flow and how to represent the strength of the causal effect. | false | false | [
"Lyn Bartram",
"Miao Yao"
] | [] | [] | [] |
EuroVis | 2,008 | Automatic Detection and Visualization of Distinctive Structures in 3D Unsteady Multi-fields | 10.1111/j.1467-8659.2008.01206.x | Current unsteady multi‐field simulation data‐sets consist of millions of data‐points. To efficiently reduce this enormous amount of information, local statistical complexity was recently introduced as a method that identifies distinctive structures using concepts from information theory. Due to high computational costs this method was so far limited to 2D data. In this paper we propose a new strategy for the computation that is substantially faster and allows for a more precise analysis. The bottleneck of the original method is the division of spatio‐temporal configurations in the field (light‐cones) into different classes of behavior. The new algorithm uses a density‐driven Voronoi tessellation for this task that more accurately captures the distribution of configurations in the sparsely sampled high‐dimensional space. The efficient computation is achieved using structures and algorithms from graph theory. The ability of the method to detect distinctive regions in 3D is illustrated using flow and weather simulations. | false | false | [
"Heike Jänicke",
"Michael Böttinger",
"Xavier Tricoche",
"Gerik Scheuermann"
] | [] | [] | [] |
EuroVis | 2,008 | Centrality Based Visualization of Small World Graphs | 10.1111/j.1467-8659.2008.01232.x | Current graph drawing algorithms enable the creation of two dimensional node‐link diagrams of huge graphs. However, for graphs with low diameter (of which “small world” graphs are a subset) these techniques begin to break down visually even when the graph has only a few hundred nodes. Typical algorithms produce images where nodes clump together in the center of the screen, making it hard to discern structure and follow paths. This paper describes a solution to this problem, which uses a global edge metric to determine a subset of edges that capture the graph's intrinsic clustering structure. This structure is then used to create an embedding of the graph, after which the remaining edges are added back in. We demonstrate applications of this technique to a number of real world examples. | false | false | [
"Frank van Ham",
"Martin Wattenberg"
] | [] | [] | [] |
EuroVis | 2,008 | Classification and Uncertainty Visualization of Dendritic Spines from Optical Microscopy Imaging | 10.1111/j.1467-8659.2008.01220.x | Neuronal dendrites and their spines affect the connectivity of neural networks, and play a significant role in many neurological conditions. Neuronal function is observed to be closely correlated with the appearance, disappearance and morphology of the spines. Automatic 3‐D reconstruction of neurons from light microscopy images, followed by the identification, classification and visualization of dendritic spines is therefore essential for studying neuronal physiology and biophysical properties. In this paper, we present a method to reconstruct dendrites using a surface representation of the dendrite. The 1‐D skeleton of the dendritic surface is then extracted by a medial geodesic function that is robust and topologically correct. This is followed by a Bayesian identification and classification of the spines. The dendrite and spines are visualized in a manner that displays the spines' types and the inherent uncertainty in identification and classification. We also describe a user study conducted to validate the accuracy of the classification and the efficacy of the visualization. | false | false | [
"Firdaus Janoos",
"Boonthanome Nouanesengsy",
"Xiaoyin Xu",
"Raghu Machiraju",
"Stephen T. C. Wong"
] | [] | [] | [] |
EuroVis | 2,008 | Code Flows: Visualizing Structural Evolution of Source Code | 10.1111/j.1467-8659.2008.01214.x | Understanding detailed changes done to source code is of great importance in software maintenance. We present Code Flows, a method to visualize the evolution of source code geared to the understanding of fine and mid‐level scale changes across several file versions. We enhance an existing visual metaphor to depict software structure changes with techniques that emphasize both following unchanged code as well as detecting and highlighting important events such as code drift, splits, merges, insertions and deletions. The method is illustrated with the analysis of a real‐world C++ code system. | false | false | [
"Alexandru C. Telea",
"David Auber"
] | [] | [] | [] |
EuroVis | 2,008 | Computing Local Signed Distance Fields for Large Polygonal Models | 10.1111/j.1467-8659.2008.01210.x | The signed distance field for a polygonal model is a useful representation that facilitates efficient computation in many visualization and geometric processing tasks. Often it is more effective to build a local distance field only within a narrow band around the surface that holds local geometric information for the model. In this paper, we present a novel technique to construct a volumetric local signed distance field of a polygonal model. To compute the local field efficiently, exactly those cells that cross the polygonal surface are found first through a new voxelization method, building a list of intersecting triangles for each boundary cell. After their neighboring cells are classified, the triangle lists are exploited to compute the local signed distance field with minimized voxel‐to‐triangle distance computations. While several efficient methods for computing the distance field, particularly those harnessing the graphics processing unit's (GPU's) processing power, have recently been proposed, we focus on a CPU‐based technique, intended to deal flexibly with large polygonal models and high‐resolution grids that are often too bulky for GPU computation. | false | false | [
"Byungjoon Chang",
"Deukhyun Cha",
"Insung Ihm"
] | [] | [] | [] |
EuroVis | 2,008 | Concurrent Viewing of Multiple Attribute-Specific Subspaces | 10.1111/j.1467-8659.2008.01208.x | In this work we present a point classification algorithm for multi‐variate data. Our method is based on the concept of attribute subspaces, which are derived from a set of user specified attribute target values. Our classification approach enables users to visually distinguish regions of saliency through concurrent viewing of these subspaces in single images. We also allow a user to threshold the data according to a specified distance from attribute target values. Based on the degree of thresholding, the remaining data points are assigned radii of influence that are used for the final coloring. This limits the view to only those points that are most relevant, while maintaining a similar visual context. | false | false | [
"Robert Sisneros",
"C. Ryan Johnson",
"Jian Huang 0007"
] | [] | [] | [] |
EuroVis | 2,008 | COPERNICUS: Context-Preserving Engine for Route Navigation with Interactive User-modifiable Scaling | 10.1111/j.1467-8659.2008.01226.x | In this paper, we present an automated system for generating context‐preserving route maps that depict navigation routes as a path between nodes and edges inside a topographic network. Our application identifies relevant context information to support navigation and orientation, and generates customizable route maps according to design principles that communicate all relevant context information clearly visible on one single page. Interactive scaling allows seamless transition between the original undistorted map and our new map design, and supports user‐specified scaling of regions of interest to create personalized driving directions according to the drivers needs. | false | false | [
"Hartmut Ziegler",
"Daniel A. Keim"
] | [] | [] | [] |
EuroVis | 2,008 | Density Displays for Data Stream Monitoring | 10.1111/j.1467-8659.2008.01222.x | In many business applications, large data workloads such as sales figures or process performance measures need to be monitored in real‐time. The data analysts want to catch problems in flight to reveal the root cause of anomalies. Immediate actions need to be taken before the problems become too expensive or consume too many resources. In the meantime, analysts need to have the “big picture” of what the information is about. In this paper, we derive and analyze two real‐time visualization techniques for managing density displays: (1) circular overlay d isplays which visualize large volumes of data without data shift movements after the display is full, thus freeing the analyst from adjusting the mental picture of the data after each data shift; and (2) variable resolution density displays which allow users to get the entire view without cluttering. We evaluate these techniques with respect to a number of evaluation measures, such as constancy of the display and usage of display space, and compare them to conventional d isplays with periodic shifts. Our real time data monitoring system also provides advanced interactions such as a local root cause analysis for further exploration. The applications using a number of real‐world data sets show the wide applicability and usefulness of our ideas. | false | false | [
"Ming C. Hao",
"Daniel A. Keim",
"Umeshwar Dayal",
"Daniela Oelke",
"Chantal Tremblay"
] | [] | [] | [] |
EuroVis | 2,008 | Discrete Multi-Material Interface Reconstruction for Volume Fraction Data | 10.1111/j.1467-8659.2008.01237.x | Material interface reconstruction (MIR) is the task of constructing boundary interfaces between regions of homogeneous material, while satisfying volume constraints, over a structured or unstructured spatial domain. In this paper, we present a discrete approach to MIR based upon optimizing the labeling of fractional volume elements within a discretization of the problem's original domain. We detail how to construct and initially label a discretization, and introduce a volume conservative swap move for optimization. Furthermore, we discuss methods for extracting and visualizing material interfaces from the discretization. Our technique has significant advantages over previous methods: we produce interfaces between multiple materials that are continuous across cell boundaries for time‐varying and static data in arbitrary dimension with bounded error. | false | false | [
"John C. Anderson",
"Christoph Garth",
"Mark A. Duchaineau",
"Kenneth I. Joy"
] | [] | [] | [] |
EuroVis | 2,008 | Evaluation of illustration-inspired techniques for time-varying data visualization | 10.1111/j.1467-8659.2008.01235.x | Illustration‐inspired techniques have provided alternative ways to visualize time‐varying data. Techniques such as speedlines, flow ribbons, strobe silhouettes and opacity‐based techniques provide temporal context to the current timestep being visualized. We evaluated the effectiveness of these illustrative techniques by conducting a user study. We compared the ability of subjects to visually track features using snapshots, snapshots augmented by illustration techniques, animations, and animations augmented by illustration techniques. User accuracy, time required to perform a task, and user confidence were used as measures to evaluate the techniques. The results indicate that the use of illustration‐inspired techniques provides a significant improvement in user accuracy and the time required to complete the task. Subjects performed significantly better on each metric when using augmented animations as compared to augmented snapshots. | false | false | [
"Alark Joshi",
"Penny Rheingans"
] | [] | [] | [] |
EuroVis | 2,008 | Exploratory Visualization of Animal Kinematics Using Instantaneous Helical Axes | 10.1111/j.1467-8659.2008.01218.x | We present novel visual and interactive techniques for exploratory visualization of animal kinematics using instantaneous helical axes (IHAs). The helical axis has been used in orthopedics, biomechanics, and structural mechanics as a construct for describing rigid body motion. Within biomechanics, recent imaging advances have made possible accurate high‐speed measurements of individual bone positions and orientations during experiments. From this high‐speed data, instantaneous helical axes of motion may be calculated. We address questions of effective interactive, exploratory visualization of this high‐speed 3D motion data. A 3D glyph that encodes all parameters of the IHA in visual form is presented. Interactive controls are used to examine the change in the IHA over time and relate the IHA to anatomical features of interest selected by a user. The techniques developed are applied to a stereoscopic, interactive visualization of the mechanics of pig mastication and assessed by a team of evolutionary biologists who found interactive IHA‐based analysis a useful addition to more traditional motion analysis techniques. | false | false | [
"Daniel F. Keefe",
"Trevor M. O'Brien",
"D. B. Baier",
"Stephen M. Gatesy",
"E. L. Brainerd",
"David H. Laidlaw"
] | [] | [] | [] |
EuroVis | 2,008 | Extraction Of Feature Lines On Surface Meshes Based On Discrete Morse Theory | 10.1111/j.1467-8659.2008.01202.x | We present an approach for extracting extremal feature lines of scalar indicators on surface meshes, based on discrete Morse Theory. By computing initial Morse‐Smale complexes of the scalar indicators of the mesh, we obtain a candidate set of extremal feature lines of the surface. A hierarchy of Morse‐Smale complexes is computed by prioritizing feature lines according to a novel criterion and applying a cancellation procedure that allows us to select the most significant lines. Given the scalar indicators on the vertices of the mesh, the presented feature line extraction scheme is interpolation free and needs no derivative estimates. The technique is insensitive to noise and depends only on one parameter: the feature significance. We use the technique to extract surface features yielding impressive, non photorealistic images. | false | false | [
"Jan Sahner",
"Britta Weber",
"Steffen Prohaska",
"Hans Lamecker"
] | [] | [] | [] |
EuroVis | 2,008 | From Web Data to Visualization via Ontology Mapping | 10.1111/j.1467-8659.2008.01230.x | In this paper, we propose a novel approach for automatic generation of visualizations from domain‐specific data available on the web. We describe a general system pipeline that combines ontology mapping and probabilistic reasoning techniques. With this approach, a web page is first mapped to a Domain Ontology, which stores the semantics of a specific subject domain (e.g., music charts). The Domain Ontology is then mapped to one or more Visual Representation Ontologies, each of which captures the semantics of a visualization style (e.g., tree maps). To enable the mapping between these two ontologies, we establish a Semantic Bridging Ontology, which specifies the appropriateness of each semantic bridge. Finally each Visual Representation Ontology is mapped to a visualization using an external visualization toolkit. Using this approach, we have developed a prototype software tool, SemViz, as a realisation of this approach. By interfacing its Visual Representation Ontologies with public domain software such as ILOG Discovery and Prefuse, SemViz is able to generate appropriate visualizations automatically from a large collection of popular web pages for music charts without prior knowledge of these web pages. | false | false | [
"O. Gilson",
"Nuno Silva 0001",
"Phil W. Grant",
"Min Chen 0001"
] | [
"BP"
] | [] | [] |
EuroVis | 2,008 | Generating Color Palettes using Intuitive Parameters | 10.1111/j.1467-8659.2008.01203.x | Color is widely used in data visualization to show data values. The proper selection of colors is critical to convey information correctly. In this paper, we present a technique for generating univariate lightness ordered palettes. These are specified via intuitive input parameters that are used define the appearance of the palette: number of colors, hue, lightness, saturation, contrast and hue range. The settings of the parameters are used to generate curves through CIELUV color space. This color space is used in order to correctly translate the requirements in terms of perceptual properties to a set of colors. The presented palette generation method enables users to specify palettes that have these perceptual properties, such as perceived order, equal perceived distance and equal importance. The technique has been integrated in Magna View, a system for multivariate data visualization. | false | false | [
"Martijn Wijffelaars",
"Roel Vliegen",
"Jarke J. van Wijk",
"Erik-Jan van der Linden"
] | [] | [] | [] |
EuroVis | 2,008 | Geometry-driven Visualization of Microscopic Structures in Biology | 10.1111/j.1467-8659.2008.01219.x | At a microscopic resolution, biological structures are composed of cells, red blood corpuscles (RBCs), cytoplasm and other microstructural components. There is a natural pattern in terms of distribution, arrangement and packing density of these components in biological organization. In this work, we propose to use N‐point correlation functions to guide the analysis and exploration process in microscopic datasets. These functions provide useful feature spaces to aid segmentation and visualization tasks. We show 3D visualizations of mouse placenta tissue layers and mouse mammary ducts as well as 2D segmentation/tracking of clonal populations. Further confidence in our results stems from validation studies that were performed with manual ground‐truth for segmentation. | false | false | [
"Kishore Mosaliganti",
"Raghu Machiraju",
"Kun Huang 0001",
"Gustavo Leone"
] | [] | [] | [] |
EuroVis | 2,008 | GPU Local Triangulation: an interpolating surface reconstruction algorithm | 10.1111/j.1467-8659.2008.01211.x | A GPU capable method for surface reconstruction from unorganized point clouds without additional information, called GLT (GPU Local Triangulation), is presented. The main objective of this research is the generation of a GPU interpolating reconstruction based on local Delaunay triangulations, inspired by a pre‐existing reconstruction algorithm. Current graphics hardware accelerated algorithms are approximating approaches, where the final triangulation is usually performed through either marching cubes or marching tetrahedras. GPU‐compatible methods and data structures to perform normal estimation and the local triangulation have been developed, plus a variation of the Bitonic Merge Sort algorithm to work with multi‐lists. Our method shows an average gain of one order of magnitude over previous research. | false | false | [
"Carlos Buchart",
"Diego Borro",
"Aiert Amundarain"
] | [] | [] | [] |
EuroVis | 2,008 | Illustrative Hybrid Visualization and Exploration of Anatomical and Functional Brain Data | 10.1111/j.1467-8659.2008.01217.x | Common practice in brain research and brain surgery involves the multi‐modal acquisition of brain anatomy and brain activation data. These highly complex three‐dimensional data have to be displayed simultaneously in order to convey spatial relationships. Unique challenges in information and interaction design have to be solved in order to keep the visualization sufficiently complete and uncluttered at the same time. The visualization method presented in this paper addresses these issues by using a hybrid combination of polygonal rendering of brain structures and direct volume rendering of activation data. Advanced rendering techniques including illustrative display styles and ambient occlusion calculations enhance the clarity of the visual output. The presented rendering pipeline produces real‐time frame rates and offers a high degree of configurability. Newly designed interaction and measurement tools are provided, which enable the user to explore the data at large, but also to inspect specific features closely. We demonstrate the system in the context of a cognitive neurosciences dataset. An initial informal evaluation shows that our visualization method is deemed useful for clinical research. | false | false | [
"Werner M. Jainek",
"Silvia Born",
"Dirk Bartz",
"Wolfgang Straßer",
"Jan Fischer"
] | [] | [] | [] |
EuroVis | 2,008 | Illustrative Parallel Coordinates | 10.1111/j.1467-8659.2008.01239.x | Illustrative parallel coordinates (IPC) is a suite of artistic rendering techniques for augmenting and improving parallel coordinate (PC) visualizations. IPC techniques can be used to convey a large amount of information about a multidimensional dataset in a small area of the screen through the following approaches: (a) edge‐bundling through splines; (b) visualization of “branched ” clusters to reveal the distribution of the data; (c) opacity‐based hints to show cluster density; (d) opacity and shading effects to illustrate local line density on the parallel axes; and (e) silhouettes, shadows and halos to help the eye distinguish between overlapping clusters. Thus, the primary goal of this work is to convey as much information as possible in a manner that is aesthetically pleasing and easy to understand for non‐experts. | false | false | [
"Kevin T. McDonnell",
"Klaus Mueller 0001"
] | [] | [] | [] |
EuroVis | 2,008 | Interaction-Dependent Semantics for Illustrative Volume Rendering | 10.1111/j.1467-8659.2008.01216.x | In traditional illustration the choice of appropriate styles and rendering techniques is guided by the intention of the artist. For illustrative volume visualizations it is difficult to specify the mapping between the 3D data and the visual representation that preserves the intention of the user. The semantic layers concept establishes this mapping with a linguistic formulation of rules that directly map data features to rendering styles. With semantic layers fuzzy logic is used to evaluate the user defined illustration rules in a preprocessing step.In this paper we introduce interaction‐dependent rules that are evaluated for each frame and are therefore computationally more expensive. Enabling interaction‐dependent rules, however, allows the use of a new class of semantics, resulting in more expressive interactive illustrations. We show that the evaluation of the fuzzy logic can be done on the graphics hardware enabling the efficient use of interaction‐dependent semantics. Further we introduce the flat rendering mode and discuss how different rendering parameters are influenced by the rule base. Our approach provides high quality illustrative volume renderings at interactive frame rates, guided by the specification of illustration rules. | false | false | [
"Peter Rautek",
"Stefan Bruckner",
"M. Eduard Gröller"
] | [] | [] | [] |
EuroVis | 2,008 | Interactive Exploratory Visualization of 2D Vector Fields | 10.1111/j.1467-8659.2008.01233.x | 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. | false | false | [
"Tobias Isenberg 0001",
"Maarten H. Everts",
"Jens Grubert",
"Sheelagh Carpendale"
] | [] | [] | [] |
EuroVis | 2,008 | Interactive Visualization for Memory Reference Traces | 10.1111/j.1467-8659.2008.01212.x | We present the Memory Trace Visualizer (MTV), a tool that provides interactive visualization and analysis of the sequence of memory operations performed by a program as it runs. As improvements in processor performance continue to outpace improvements in memory performance, tools to understand memory access patterns are increasingly important for optimizing data intensive programs such as those found in scientific computing. Using visual representations of abstract data structures, a simulated cache, and animating memory operations, MTV can expose memory performance bottlenecks and guide programmers toward memory system optimization opportunities. Visualization of detailed memory operations provides a powerful and intuitive way to expose patterns and discover bottlenecks, and is an important addition to existing statistical performance measurements. | false | false | [
"A. N. M. Imroz Choudhury",
"Kristin C. Potter",
"Steven G. Parker"
] | [] | [] | [] |
EuroVis | 2,008 | Interactive Visualization of Multimodal Volume Data for Neurosurgical Tumor Treatment | 10.1111/j.1467-8659.2008.01242.x | We present novel interactive methods for the visualization of multimodal volume data as used in neurosurgical therapy planning. These methods allow surgeons to explore multimodal volumes and focus on functional data and lesions. Computer graphics techniques are proposed to create expressive visualizations at interactive frame rates to reduce time‐consuming and complex interaction with the medical data. Contributions of our work are the distance‐based enhancements of functional data and lesions which allows the surgeon to perceive functional and anatomical structures at once and relate them directly to the intervention. In addition we propose methods for the visual exploration of the path to the structures of interest, to enhance anatomical landmarks, and to provide additional depth indicators. These techniques have been integrated in a visualization prototype that provides interaction capabilities for finding the optimal therapeutic strategy for the neurosurgeon. | false | false | [
"Christian Rieder",
"Felix Ritter",
"Matthias Raspe",
"Heinz-Otto Peitgen"
] | [] | [] | [] |
EuroVis | 2,008 | Investigative Visual Analysis of Global Terrorism | 10.1111/j.1467-8659.2008.01225.x | Recent increases in terrorist activity around the world have made analyzing and understanding such activities more critical than ever. With the help of organizations such as the National Center for the Study of Terrorism and Responses to Terrorism (START), we now have detailed historical information on each terrorist event around the world since 1970. However, due to the size and complexity of the data, identifying terrorists' patterns and trends has been difficult. To better enable investigators in understanding terrorist activities, we propose a visual analytical system that focuses on depicting one of the most fundamental concepts in investigative analysis, the five W's (who, what, where, when, and why). Views in our system are highly correlated, and each represents one of the W's. With this approach, an investigator can interactively explore terrorist activities efficiently and discover reasons of attacks (why) by identifying patterns temporally (when), geo‐spatially (where), between multiple terrorist groups (who), and across different methods or modes of attacks (what). By coupling a global perspective with the details gleaned from asking these five questions, the system allows analysts to think both tactically and strategically. | false | false | [
"Xiaoyu Wang 0001",
"Erin Miller",
"Kathleen Smarick",
"William Ribarsky",
"Remco Chang"
] | [] | [] | [] |
EuroVis | 2,008 | Lagrangian Visualization of Flow-Embedded Surface Structures | 10.1111/j.1467-8659.2008.01236.x | The notions of Finite‐Time Lyapunov Exponent (FTLE) and Lagrangian Coherent Structures provide a strong framework for the analysis and visualization of complex technical flows. Their definition is simple and intuitive, and they are built on a deep theoretical foundation. We apply these concepts to enable the analysis of flows in the immediate vicinity of the boundaries of flow‐embedded objects by limiting the Lagrangian analysis to surfaces closely neighboring these boundaries. To this purpose, we present an approach to approximate FTLE fields over such surfaces. Furthermore, we achieve an effective depiction of boundary‐related flow structures such as separation and attachment over object boundaries and specific insight into the surrounding flow using several specifically chosen visualization techniques. We document the applicability of our methods by presenting a number of application examples. | false | false | [
"Christoph Garth",
"Alexander Wiebel",
"Xavier Tricoche",
"Kenneth I. Joy",
"Gerik Scheuermann"
] | [] | [] | [] |
EuroVis | 2,008 | Navigation and Exploration of Interconnected Pathways | 10.1111/j.1467-8659.2008.01229.x | Visualizing pathways, i. e. models of cellular functional networks, is a challenging task in computer assisted biomedicine. Pathways are represented as large collections of interwoven graphs, with complex structures present in both the individual graphs and their interconnections. This situation requires the development of novel visualization techniques to allow efficient visual exploration. We present the Caleydo framework, which incorporates a number of approaches to handle such pathways. Navigation in the network of pathways is facilitated by a hierarchical approach which dynamically selects a working set of individual pathways for closer inspection. These pathways are interactively rendered together with visual interconnections in a 2.5D view using graphics hardware acceleration. The layout of individual graphs is not computed automatically, but taken from the KEGG and BioCarta databases, which use layouts that life scientists are familiar with. Therefore they encode essential meta‐information. While the KEGG and BioCarta pathways use a pre‐defined layout, interactions such as linking+brushing, neighborhood search or detail on demand are still fully interactive in Caleydo. We have evaluated Caleydo with pathologists working on the determination of unknown gene functions. Informal experiences confirm that Caleydo is useful in both generating and validating such hypotheses.Even though the presented techniques are applied to medical pathways, the proposed way of interaction is not limited to cellular processes and therefore has the potential to open new possibilities in other fields of application. | false | false | [
"Marc Streit",
"Michael Kalkusch",
"Karl Kashofer",
"Dieter Schmalstieg"
] | [] | [] | [] |
EuroVis | 2,008 | Particle Level Set Advection for the Interactive Visualization of Unsteady 3D Flow | 10.1111/j.1467-8659.2008.01200.x | Typically, flow volumes are visualized by defining their boundary as iso‐surface of a level set function. Grid‐based level sets offer a good global representation but suffer from numerical diffusion of surface detail, whereas particle‐based methods preserve details more accurately but introduce the problem of unequal global representation. The particle level set (PLS) method combines the advantages of both approaches by interchanging the information between the grid and the particles. Our work demonstrates that the PLS technique can be adapted to volumetric dye advection via streak volumes, and to the visualization by time surfaces and path volumes. We achieve this with a modified and extended PLS, including a model for dye injection. A new algorithmic interpretation of PLS is introduced to exploit the efficiency of the GPU, leading to interactive visualization. Finally, we demonstrate the high quality and usefulness of PLS flow visualization by providing quantitative results on volume preservation and by discussing typical applications of 3D flow visualization. | false | false | [
"Nicolas Cuntz",
"Andreas Kolb 0001",
"Robert Strzodka",
"Daniel Weiskopf"
] | [] | [] | [] |
EuroVis | 2,008 | Physically-based Dye Advection for Flow Visualization | 10.1111/j.1467-8659.2008.01201.x | Dye advection is widely used in experimental flow analysis but has seen less use for visualization in computational fluid dynamics. One possible reason for this disconnect is the inaccuracy of the texture‐based approach, which is prone to artifacts caused by numeric diffusion and mass fluctuation. In this paper, we introduce a novel 2D dye advection scheme for flow visualization based on the concept of control volume analysis typically used in computational fluid dynamics. The evolution of dye patterns in the flow field is achieved by advecting individual control volumes, which collectively cover the entire spatial domain. The local variation of dye material, represented as a piecewise quasi‐parabolic function, is integrated within each control volume resulting in mass conserving transport without excessive numerical diffusion. Due to its physically based formulation, this approach is capable of conveying intricate flow structures not shown in the traditional dye advection schemes while avoiding visual artifacts. | false | false | [
"Guo-Shi Li",
"Xavier Tricoche",
"Charles D. Hansen"
] | [] | [] | [] |
EuroVis | 2,008 | Quality Isosurface Mesh Generation Using an Extended Marching Cubes Lookup Table | 10.1111/j.1467-8659.2008.01209.x | The Marching Cubes Algorithm may return degenerate, zero area isosurface triangles, and often returns isosurface triangles with small areas, edges or angles. We show how to avoid both problems using an extended Marching Cubes lookup table. As opposed to the conventional Marching Cubes lookup table, the extended lookup table differentiates scalar values equal to the isovalue from scalar values greater than the isovalue. The lookup table has 38= 6561 entries, based on three possible labels, ‘−’ or ‘=’ or ‘+’, of each cube vertex. We present an algorithm based on this lookup table which returns an isosurface close to the Marching Cubes isosurface, but without any degenerate triangles or any small areas, edges or angles. | false | false | [
"Sundaresan Raman",
"Rephael Wenger"
] | [] | [] | [] |
EuroVis | 2,008 | Raycasting of Light Field Galleries from Volumetric Data | 10.1111/j.1467-8659.2008.01215.x | The paper describes a technique to generate high‐quality light field representations from volumetric data. We show how light field galleries can be created to give unexperienced audiences access to interactive high‐quality volume renditions. The proposed light field representation is lightweight with respect to storage and bandwidth capacity and is thus ideal as exchange format for visualization results, especially for web galleries.The approach expands an existing sphere‐hemisphere parameterization for the light field with per‐pixel depth. High‐quality paraboloid maps from volumetric data are generated using GPU‐based ray‐casting or slicing approaches. Different layers, such as isosurfaces, but not restricted to, can be generated independently and composited in real time. This allows the user to interactively explore the model and to change visibility parameters at run‐time. | false | false | [
"Christof Rezk-Salama",
"Severin Todt",
"Andreas Kolb 0001"
] | [] | [] | [] |
EuroVis | 2,008 | Results of a User Study on 2D Hurricane Visualization | 10.1111/j.1467-8659.2008.01234.x | We present the results from a user study looking at the ability of observers to mentally integrate wind direction and magnitude over a vector field. The data set chosen for the study is an MM5 (PSU/NCAR Mesoscale Model) simulation of Hurricane Lili over the Gulf of Mexico as it approaches the southeastern United States. Nine observers participated in the study. This study investigates the effect of layering on the observer's ability to determine the magnitude and direction of a vector field. We found a tendency for observers to underestimate the magnitude of the vectors and a counter‐clockwise bias when determining the average direction of a vector field. We completed an additional study with two observers to try to uncover the source of the counter‐clockwise bias. These results have direct implications to atmospheric scientists, but may also be able to be applied to other fields that use 2D vector fields. | false | false | [
"Joel P. Martin",
"J. Edward Swan II",
"Robert J. Moorhead II",
"Zhanping Liu",
"Shangshu Cai"
] | [] | [] | [] |
EuroVis | 2,008 | Sound Tracing: Rendering Listener Specific Acoustic Room Properties | 10.1111/j.1467-8659.2008.01228.x | We present an acoustic rendering approach visualizing the listener‐specific contribution of frequency‐dependent pressure fields on a scene geometry with acoustic reflection and scattering properties. Our method facilitates the evaluation of simulated acoustics showing the effect of simulation parameters like absorption and scattering. The image‐based spatial localization of acoustic properties is complementary to the auditive evaluation by means of auralization. Our core contribution is a pressure‐based acoustic rendering equation and a corresponding raytracing method applying techniques from photorealistic rendering to the field of simulated room acoustics. Applications are directed at the visualization of interference patterns and analyzing the impact of acoustic reflection parameters. | false | false | [
"Jens Bellmann",
"Frank Michel 0001",
"Eduard Deines",
"Martin Hering-Bertram",
"Jan Mohring",
"Hans Hagen"
] | [] | [] | [] |
EuroVis | 2,008 | TimeRadarTrees: Visualizing Dynamic Compound Digraphs | 10.1111/j.1467-8659.2008.01213.x | The evolution of dependencies in information hierarchies can be modeled by sequences of compound digraphs with edge weights. In this paper we present a novel approach to visualize such sequences of graphs. It uses radial tree layout to draw the hierarchy, and circle sectors to represent the temporal change of edges in the digraphs. We have developed several interaction techniques that allow the users to explore the structural and temporal data. Smooth animations help them to track the transitions between views. The usefulness of the approach is illustrated by examples from very different application domains. | false | false | [
"Michael Burch",
"Stephan Diehl 0001"
] | [] | [] | [] |
EuroVis | 2,008 | Topology-Preserving lambda2-based Vortex Core Line Detection for Flow Visualization | 10.1111/j.1467-8659.2008.01238.x | We propose a novel vortex core line extraction method based on the λ2 vortex region criterion in order to improve the detection of vortex features for 3D flow visualization. The core line is defined as a curve that connects λ2 minima restricted to planes that are perpendicular to the core line. The basic algorithm consists of the following stages: (1) λ2 field construction and isosurface extraction; (2) computation of the curve skeleton of the λ2 isosurface to build an initial prediction for the core line; (3) correction of the locations of the prediction by searching for λ2 minima on planes perpendicular to the core line. In particular, we consider the topology of the vortex core lines, guaranteeing the same topology as the initial curve skeleton. Furthermore, we propose a geometry‐guided definition of vortex bifurcation, which represents the split of one core line into two parts. Finally, we introduce a user‐guided approach in order to narrow down vortical regions taking into account the graph of λ2 along the computed vortex core line. We demonstrate the effectiveness of our method by comparing our results to previous core line detection methods with both simulated and experimental data; in particular, we show robustness of our method for noise‐affected data. | false | false | [
"Tobias Schafhitzel",
"Joachim E. Vollrath",
"Joao Paulo Gois",
"Daniel Weiskopf",
"Antônio Castelo Filho",
"Thomas Ertl"
] | [] | [] | [] |
EuroVis | 2,008 | Towards closing the analysis gap: Visual generation of decision supporting schemes from raw data | 10.1111/j.1467-8659.2008.01224.x | The derivation, manipulation and verification of analytical models from raw data is a process which requires a transformation of information across different levels of abstraction. We introduce a concept for the coupling of data classification and interactive visualization in order to make this transformation visible and steerable for the human user. Data classification techniques generate mappings that formally group data items into categories. Interactive visualization includes the user into an iterative refinement process. The user identifies and selects interesting patterns to define these categories. The following step is the transformation of a visible pattern into the formal definition of a classifier. In the last step the classifier is transformed back into a pattern that is blended with the original data in the same visual display. Our approach allows in intuitive assessment of a formal classifier and its model, the detection of outliers and the handling of noisy data using visual pattern‐matching. We instantiated the concept using decision trees for classification and KVMaps as the visualization technique. The generation of a classifier from visual patterns and its verification is transformed from a cognitive to a mostly pre‐cognitive task. | false | false | [
"Thorsten May",
"Jörn Kohlhammer"
] | [] | [] | [] |
EuroVis | 2,008 | Virtual Klingler Dissection: Putting Fibers into Context | 10.1111/j.1467-8659.2008.01243.x | Fiber tracking is a standard tool to estimate the course of major white matter tracts from diffusion tensor magnetic resonance imaging (DT‐MRI) data. In this work, we aim at supporting the visual analysis of classical streamlines from fiber tracking by integrating context from anatomical data, acquired by a T1‐weighted MRI measurement. To this end, we suggest a novel visualization metaphor, which is based on data‐driven deformation of geometry and has been inspired by a technique for anatomical fiber preparation known as Klingler dissection. We demonstrate that our method conveys the relation between streamlines and surrounding anatomical features more effectively than standard techniques like slice images and direct volume rendering. The method works automatically, but its GPU‐based implementation allows for additional, intuitive interaction. | false | false | [
"Thomas Schultz 0001",
"Natascha Sauber",
"Alfred Anwander",
"Holger Theisel",
"Hans-Peter Seidel"
] | [] | [] | [] |
EuroVis | 2,008 | Visual Abstractions of Solvent Pathlines near Protein Cavities | 10.1111/j.1467-8659.2008.01227.x | Water is known to play a crucial role in protein structure, flexibility and activity. The use of molecular dynamics simulations allows detailed studies of complex protein‐solvent interactions. Cluster analysis and density‐based approaches have been successfully used for the identification and analysis of conserved water molecules and hydration patterns of proteins. However, appropriate tools for analysing long‐time molecular dynamics simulations with respect to tracking and visualising the paths of solvent molecules are lacking. Our method focuses on visualising the solvent paths entering and leaving cavities of the protein and allows to study the route and dynamics of the exchange of tightly bound internal water molecules with the bulk solvent. The proposed visualisation also represents dynamic properties such as direction and velocity in the solvent. Especially, by clustering similar path‐lines with respect to designated properties the visualisation can be abstracted to represent the principal paths of solvent molecules through the cavities. Its application in the analysis of long‐time scale molecular dynamics simulations not only confirmed conjectures based on previous manual observations made by chance, but also led to novel insights into the dynamical and structural role of water molecules and its interplay with protein structure. | false | false | [
"Katrin Bidmon",
"Sebastian Grottel",
"Fabian Bös",
"Jürgen Pleiss",
"Thomas Ertl"
] | [] | [] | [] |
EuroVis | 2,008 | Visual Analysis and Semantic Exploration of Urban LIDAR Change Detection | 10.1111/j.1467-8659.2008.01223.x | Many previous approaches to detecting urban change from LIDAR point clouds interpolate the points into rasters, perform pixel‐based image processing to detect changes, and produce 2D images as output. We present a method of LIDAR change detection that maintains accuracy by only using the raw, irregularly spaced LIDAR points, and extracts relevant changes as individual 3D models. We then utilize these models, alongside existing GIS data, within an interactive application that allows the chronological exploration of the changes to an urban environment. A three‐tiered level‐of‐detail system maintains a scale‐appropriate, legible visual representation across the entire range of view scales, from individual changes such as buildings and trees, to groups of changes such as new residential developments, deforestation, and construction sites, and finally to larger regions such as neighborhoods and districts of a city that are emerging or undergoing revitalization. Tools are provided to assist the visual analysis by urban planners and historians through semantic categorization and filtering of the changes presented. | false | false | [
"Thomas Butkiewicz",
"Remco Chang",
"Zachary Wartell",
"William Ribarsky"
] | [] | [] | [] |
EuroVis | 2,008 | Visual Clustering in Parallel Coordinates | 10.1111/j.1467-8659.2008.01241.x | Parallel coordinates have been widely applied to visualize high‐dimensional and multivariate data, discerning patterns within the data through visual clustering. However, the effectiveness of this technique on large data is reduced by edge clutter. In this paper, we present a novel framework to reduce edge clutter, consequently improving the effectiveness of visual clustering. We exploit curved edges and optimize the arrangement of these curved edges by minimizing their curvature and maximizing the parallelism of adjacent edges. The overall visual clustering is improved by adjusting the shape of the edges while keeping their relative order. The experiments on several representative datasets demonstrate the effectiveness of our approach. | false | false | [
"Hong Zhou 0004",
"Xiaoru Yuan",
"Huamin Qu",
"Weiwei Cui",
"Baoquan Chen"
] | [] | [] | [] |
EuroVis | 2,008 | Visual Comparison of Hierarchically Organized Data | 10.1111/j.1467-8659.2008.01205.x | We provide a novel visualization method for the comparison of hierarchically organized data. Our technique visualizes a pair of hierarchies that are to be compared and simultaneously depicts how these hierarchies are related by explicitly visualizing the relations between matching subhierarchies. Elements that are unique to each hierarchy are shown, as well as the way in which hierarchy elements are relocated, split or joined. The relations between hierarchy elements are visualized using Hierarchical Edge Bundles (HEBs). HEBs reduce visual clutter, they visually emphasize the aforementioned splits, joins, and relocations of subhierarchies, and they provide an intuitive way in which users can interact with the relations. The focus throughout this paper is on the comparison of different versions of hierarchically organized software systems, but the technique is applicable to other kinds of hierarchical data as well. Various data sets of actual software systems are used to show how our technique can be employed to easily spot splits, joins, and relocations of elements, how sorting both hierarchies with respect to each other facilitates comparison tasks, and how user interaction is supported. | false | false | [
"Danny Holten",
"Jarke J. van Wijk"
] | [] | [] | [] |
EuroVis | 2,008 | Visual Inspection of Multivariate Graphs | 10.1111/j.1467-8659.2008.01231.x | Most graph visualization techniques focus on the structure of graphs and do not offer support for dealing with node attributes and edge labels. To enable users to detect relations and patterns in terms of data associated with nodes and edges, we present a technique where this data plays a more central role. Nodes and edges are clustered based on associated data. Via direct manipulation users can interactively inspect and query the graph. Questions that can be answered include, “which edge types are activated by specific node attributes?” and, “how and from where can I reach specific types of nodes?” To validate our approach we contrast it with current practice. We also provide several examples where our method was used to study transition graphs that model real‐world systems. | false | false | [
"A. Johannes Pretorius",
"Jarke J. van Wijk"
] | [] | [] | [] |
EuroVis | 2,008 | Visualizing Genome Expression and Regulatory Network Dynamics in Genomic and Metabolic Context | 10.1111/j.1467-8659.2008.01221.x | DNA microarrays are used to measure the expression levels of thousands of genes simultaneously. In a time series experiment, the gene expressions are measured as a function of time. We present an application for integrated visualization of genome expression and network dynamics in both regulatory networks and metabolic pathways. Integration of these two levels of cellular processes is necessary, since it provides the link between the measurements at the transcriptional level (gene expression levels approximated from microarray data) and the phenotype (the observable characteristics of an organism) at the functional and behavioral level. The integration requires visualization approaches besides traditional clustering and statistical analysis methods. Our application can (i) visualize the data from time series experiments in the context of a regulatory network and KEGG metabolic pathways; (ii) identify and visualize active regulatory subnetworks from the gene expression data; (iii) perform a statistical test to identify and subsequently visualize pathways that are affected by differentially expressed genes. We present a case study, which demonstrates that our approach and application both facilitates and speeds up data analysis tremendously in comparison to a more traditional approach that involves many manual, laborious, and error‐prone steps. | false | false | [
"Michel A. Westenberg",
"Sacha A. F. T. van Hijum",
"Oscar P. Kuipers",
"Jos B. T. M. Roerdink"
] | [] | [] | [] |
CHI | 2,008 | An exploratory study of visual information analysis | 10.1145/1357054.1357245 | 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. | false | false | [
"Petra Isenberg",
"Anthony Tang 0001",
"Sheelagh Carpendale"
] | [] | [] | [] |
CHI | 2,008 | ArtLinks: fostering social awareness and reflection in museums | 10.1145/1357054.1357121 | Technologies in museums often support learning goals, providing information about exhibits. However, museum visitors also desire meaningful experiences and enjoy the social aspects of museum-going, values ignored by most museum technologies. We present ArtLinks, a visualization with three goals: helping visitors make connections to exhibits and other visitors by highlighting those visitors who share their thoughts; encouraging visitors' reflection on the social and liminal aspects of museum-going and their expectations of technology in museums; and doing this with transparency, aligning aesthetically pleasing elements of the design with the goals of connection and reflection. Deploying ArtLinks revealed that people have strong expectations of technology as an information appliance. Despite these expectations, people valued connections to other people, both for their own sake and as a way to support meaningful experience. We also found several of our design choices in the name of transparency led to unforeseen tradeoffs between the social and the liminal. | false | false | [
"Dan Cosley",
"Joel Lewenstein",
"Andrew Herman",
"Jenna Holloway",
"Jonathan Baxter",
"Saeko Nomura",
"Kirsten Boehner",
"Geri Gay"
] | [] | [] | [] |
CHI | 2,008 | Do I live in a flood basin?: synthesizing ten thousand maps | 10.1145/1357054.1357100 | The recent introduction of simple, web-based geographic visualization interfaces has unleashed a tidal wave of new geographic content now available on the Internet. There has been enormous attention on the development of data interchange standards and programming interfaces that make all this content interoperable, but far less thought about how the user experience should change when users have their choice of 10,000 maps. To inform the design of online mapping systems, we investigate the case of queries that require correlation of multiple maps---that is, discovery and synthesis of several map layers. We based our study on interviews with expert users of maps: archivists and librarians. This paper describes our user-task taxonomy distilled from these interviews, and presents MapSynthesizer, a prototype system that allows users to efficiently query, discover, and integrate many maps from a corpus of thousands. | false | false | [
"Miguel Elías",
"Jeremy Elson",
"Danyel Fisher",
"Jon Howell"
] | [] | [] | [] |
CHI | 2,008 | Do visualizations improve synchronous remote collaboration? | 10.1145/1357054.1357246 | Information visualizations can improve collaborative problem solving, but this improvement may depend on whether visualizations promote communication. In an experiment on the effect of network visualizations, remote pairs worked synchronously to identify a serial killer. They discussed disparate evidence distributed across the pair using IM. Four conditions, respectively, offered (a) spreadsheet only (controls), (b) individual unshared visualizations, (c) view-only shared visualizations, and (d) a full-access shared visualization of all evidence. We examined collaborative performance, use of the visualization tool, and communication as a function of condition. All visualization conditions improved remote collaborators' performance over the control condition. Full access to a shared visualization best facilitated remote collaboration by encouraging tool use and fostering discussion between the partners. Shared visualization without full access impaired performance somewhat and made communication even more vital to identifying the serial killer. This study provides direct evidence of visualization tool features and partner behavior that promote collaboration. | false | false | [
"Aruna D. Balakrishnan",
"Susan R. Fussell",
"Sara B. Kiesler"
] | [] | [] | [] |
CHI | 2,008 | Expandable grids for visualizing and authoring computer security policies | 10.1145/1357054.1357285 | We introduce the Expandable Grid, a novel interaction technique for creating, editing, and viewing many types of security policies. Security policies, such as file permissions policies, have traditionally been displayed and edited in user interfaces based on a list of rules, each of which can only be viewed or edited in isolation. These list-of-rules interfaces cause problems for users when multiple rules interact, because the interfaces have no means of conveying the interactions amongst rules to users. Instead, users are left to figure out these rule interactions themselves. An Expandable Grid is an interactive matrix visualization designed to address the problems that list-of-rules interfaces have in conveying policies to users. This paper describes the Expandable Grid concept, shows a system using an Expandable Grid for setting file permissions in the Microsoft Windows XP operating system, and gives results of a user study involving 36 participants in which the Expandable Grid approach vastly outperformed the native Windows XP file-permissions interface on a broad range of policy-authoring tasks. | false | false | [
"Robert W. Reeder",
"Lujo Bauer",
"Lorrie Faith Cranor",
"Michael K. Reiter",
"Kelli Bacon",
"Keisha How",
"Heather Strong"
] | [] | [] | [] |
CHI | 2,008 | Generalized selection via interactive query relaxation | 10.1145/1357054.1357203 | Selection is a fundamental task in interactive applications, typically performed by clicking or lassoing items of interest. However, users may require more nuanced forms of selection. Selecting regions or attributes may be more important than selecting individual items. Selections may be over dynamic items and selections might be more easily created by relaxing simpler selections (e.g., "select all items like this one"). Creating such selections requires that interfaces model the declarative structure of the selection, not just individually selected items. We present direct manipulation techniques that couple declarative selection queries with a query relaxation engine that enables users to interactively generalize their selections. We apply our selection techniques in both information visualization and graphics editing applications, enabling generalized selection over both static and dynamic interface objects. A controlled study finds that users create more accurate selection queries when using our generalization techniques. | false | false | [
"Jeffrey Heer",
"Maneesh Agrawala",
"Wesley Willett"
] | [] | [] | [] |
CHI | 2,008 | Handsaw: tangible exploration of volumetric data by direct cut-plane projection | 10.1145/1357054.1357098 | Tangible User Interfaces are well-suited to handling three-dimensional data sets by direct manipulation of real objects in space, but current interfaces can make it difficult to look inside dense volumes of information. This paper presents the Handsaw, a system that detects a virtual cut-plane projected by an outstretched hand or laser-line directly on an object or space and reveals sectional data on an adjacent display. By leaving the hands free and using a remote display, these techniques can be shared between multiple users and integrated into everyday practice. The Handsaw has been prototyped for scientific visualizations in medicine, engineering and urban design. User evaluations suggest that using a hand is more intuitive while projected light is more precise than keyboard and mouse control, and the Handsaw system has the potential to be used effectively by novices and in groups. | false | false | [
"Leonardo Bonanni",
"Jason Alonso",
"Neil Chao",
"Greg Vargas",
"Hiroshi Ishii 0001"
] | [] | [] | [] |
CHI | 2,008 | Integrating statistics and visualization: case studies of gaining clarity during exploratory data analysis | 10.1145/1357054.1357101 | Although both statistical methods and visualizations have been used by network analysts, exploratory data analysis remains a challenge. We propose that a tight integration of these technologies in an interactive exploratory tool could dramatically speed insight development. To test the power of this integrated approach, we created a novel social network analysis tool, SocialAction, and conducted four long-term case studies with domain experts, each working on unique data sets with unique problems. The structured replicated case studies show that the integrated approach in SocialAction led to significant discoveries by a political analyst, a bibliometrician, a healthcare consultant, and a counter-terrorism researcher. Our contributions demonstrate that the tight integration of statistics and visualizations improves exploratory data analysis, and that our evaluation methodology for long-term case studies captures the research strategies of data analysts. | false | false | [
"Adam Perer",
"Ben Shneiderman"
] | [] | [] | [] |
CHI | 2,008 | LiveRAC: interactive visual exploration of system management time-series data | 10.1145/1357054.1357286 | We present LiveRAC, a visualization system that supports the analysis of large collections of system management time-series data consisting of hundreds of parameters across thousands of network devices. LiveRAC provides high information density using a reorderable matrix of charts, with semantic zooming adapting each chart's visual representation to the available space. LiveRAC allows side-by-side visual comparison of arbitrary groupings of devices and parameters at multiple levels of detail. A staged design and development process culminated in the deployment of LiveRAC in a production environment. We conducted an informal longitudinal evaluation of LiveRAC to better understand which proposed visualization techniques were most useful in the target environment. | false | false | [
"Peter McLachlan",
"Tamara Munzner",
"Eleftherios Koutsofios",
"Stephen C. North"
] | [] | [] | [] |
CHI | 2,008 | LivOlay: interactive ad-hoc registration and overlapping of applications for collaborative visual exploration | 10.1145/1357054.1357266 | The interoperability of disparate data types and sources has been a long standing problem and a hindering factor for the efficacy and efficiency in visual exploration applications. In this paper, we present a solution, called LivOlay, that enables the rapid visual overlay of live data rendered in different applications. Our tool addresses datasets in which visual registration of the information is necessary in order to allow for thorough understanding and visual analysis. We also discuss initial evaluation and user feedback of LivOlay. | false | false | [
"Hao Jiang",
"Daniel Wigdor",
"Clifton Forlines",
"Michelle Borkin",
"Jens Kauffmann",
"Chia Shen"
] | [] | [] | [] |
CHI | 2,008 | Metrics for measuring human interaction with interactive visualizations for information analysis | 10.1145/1357054.1357287 | There is a lack of widely-accepted metrics for evaluating analysts' experiences with interactive visualizations (IV) for information analysis. We report an approach for developing analyst-centered IV metrics that is built upon understanding the workplace needs and experiences of information analysts with respect to IVs. We derive metrics from human-computer interaction heuristics, specializing the metrics to address the characteristics of IVs and analysts. When there are no existing heuristics, analysts' needs and experiences inform new heuristics. | false | false | [
"Theresa A. O'Connell",
"Yee-Yin Choong"
] | [] | [] | [] |
CHI | 2,008 | On the benefits of confidence visualization in speech recognition | 10.1145/1357054.1357288 | In a typical speech dictation interface, the recognizer's best-guess is displayed as normal, unannotated text. This ignores potentially useful information about the recognizer's confidence in its recognition hypothesis. Using a confidence measure (which itself may sometimes be inaccurate), we investigated providing visual feedback about low-confidence portions of the recognition using shaded, red underlining. An evaluation showed, compared to a baseline without underlining, underlining low-confidence areas did not increase user's speed or accuracy in detecting errors. However, we found that when recognition errors were correctly underlined, they were discovered significantly more often than baseline. Conversely, when errors failed to be underlined, they were discovered less often. Our results indicate confidence visualization can be effective --- but only if the confidence measure has high accuracy. Further, since our results show that users tend to trust confidence visualization, designers should be careful in its application if a high accuracy confidence measure is not available. | false | false | [
"Keith Vertanen",
"Per Ola Kristensson"
] | [] | [] | [] |
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