10241 Abstracts Collection -- Information Visualization

From 13.06.10 to 18.06.10, the Dagstuhl Seminar 10241 ``Information Visualization \u27\u27 was held in Schloss Dagstuhl~--~Leibniz Center for Informatics. During the seminar, several participants presented their current research, and ongoing work and open problems were discussed. Abstracts of the presentations given during the seminar as well as abstracts of seminar results and ideas are put together in this paper. The first section describes the seminar topics and goals in general. Links to extended abstracts or full papers are provided, if available

10241 Executive Summary -- Information Visualization

Information Visualization (InfoVis) focuses on the use of visualization techniques to help people understand and analyze data. While related fields such as Scientific Visualization involve the presentation of data that has some physical or geometric correspondence, Information Visualization centers on abstract information without such correspondences. The aim of this seminar was to bring together theoreticians and practitioners from the field with a special focus on the intersection of InfoVis and Human-Computer Interaction. To support discussions that are related to the visualization of real world data, researchers from selected application areas also attended and contributed. During the seminar, working groups on eight different topics were formed and enabled a critical reflection on ongoing research efforts, the state of the field, and key research challenges today

07221 Executive Summary - Information Visualization - Human-Centered Issues in Visual Representation, Interaction, and Evaluation

Information Visualization (InfoVis) focuses on the use of visualization techniques to help people understand and analyze data. While related fields such as Scientific Visualization involve the presentation of data that has some physical or geometric correspondence, Information Visualization centers on abstract information without such correspondences. One important aim of this seminar was to bring together theoreticians and practitioners from Information Visualization and related fields as well as from application areas. The seminar has allowed a critical reflection on actual research efforts, the state of field, evaluation challenges, etc. This document summarizes the event

A Methodology for Building Application-Specific Visualizations of Parallel Programs

Visualization of computer programs, particularly parallel programs, promises to help programmers better understand, develop, and debug their code, especially if the visualizations are relatively easy to create. We have developed a visualization methodology being used as a component in a comprehensive parallel program visualization system. The focus of the system is on application-specific user-tailored program views. An application-specific visualization of a parallel program presents the inherent application domain, semantics, and data being manipulated by the program in a manner natural to one's understanding of the program. In this paper we discuss why application-specific views are necessary for program debugging, and we list several requirements and challenges that a system for applicationspecific viewing should meet. The visualization methodology that we introduce includes primitives for designing smooth animation scenarios, and most importantly, for allowing designers to visualize or showcase the concurrency exhibited by parallel programs

Visualizing the Execution of Threads-based Parallel Programs

One popular model of concurrent computing is threads-based parallel programming on a shared memory parallel computer. A variety of different vendors and machines provide such capabilities, and support for threads programming has begun to appear in desktop multiprocessor systems such as the Sun SPARCstation 20. Unfortunately, building parallel programs that use threads is still quite challenging, even for veteran serial programmers. This stems from the difficulty of controlling communication and synchronization between the different processes. We believe that the use of program visualization tools that graphically depict the state of a program's execution can help programmers develop, debug, and understand their code faster and more easily. Most program visualization systems for parallel computation have focused on performance views and views of message passing systems. Here, we introduce a presentation methodology and a set of views particularly appropriate for depicting the execution of threads-based parallel programs. These views were created specifically for the pthreads programming library on a KSR machine, but they could easily be adapted to other threads-based systems. We also describe our techniques for gathering program execution data to drive the views, and we discuss what an ideal program tracing environment should provide to support the views we developed

An Empirical Study of the Effect of Agent Competence on User Performance and Perception

We studied the role of the competence of a user interface agent/assistant that helped users to learn and use a new text editor. Participants in the study made a set of prescribed changes to a document via the editor with the aid of one of four interface agents. Participants could ask questions out loud to the agent and the agent would respond using a synthesized voice; the agent would also make proactive suggestions. The agents varied in the quality of responses and suggestions made. One group of participants were provided with a help screen as well as the agent. We focused on assessing the relation between users' objective performance, interaction style, and subjective experience. Results revealed that the perceived utility of the agent was influenced by the types of errors made by the agent, while participants' subjective impressions of the agent related to the perceptions of its representation. In addition, allowing participants to choose their preferred assistance style(s) (agent vs. online-help) improved objective performance. We correlate quantitative findings with qualitative interview data and discuss implications for the design and the implementation of systems with interface agents

Anthropomorphic Agents as a UI Paradigm: Experimental Findings and a Framework for Research

Research on anthropomorphic agent interfaces has produced widely divergent results. We suggest that this is due to insufficient consideration of key factors that influence the perception and effectiveness of agent-based interfaces. Thus, we propose a framework for studying anthropomorphic agents that can systematize the research. The framework emphasizes features of the agent, the user, and the task the user is performing. Our initial experiment within this framework manipulated the agent's appearance (lifelike versus iconic) and the nature of the user's task (carrying out procedures versus providing opinions). We found that the perception of the agent was strongly influenced by the task while features of the agent that we manipulated had little effect

Is a Picture Worth a Thousand Words? An Evaluation of Information Awareness Displays

Little is known about what makes a peripheral or ambient display effective at presenting awareness information or simply, if one is better than another. Furthermore, techniques for evaluating these types of displays are just beginning to be developed. We conducted an evaluation of the InfoCanvas, a peripheral display that conveys awareness information graphically as a form of information art. We assessed people's comprehension of information presented by the InfoCanvas compared to two other electronic information displays, a Web portal style and a text-based display, when each display was viewed for a short period of time. We found that participants noted and recalled significantly more information when presented by the InfoCanvas than by either of the other displays despite having to learn the additional graphical representations employed by the InfoCanvas

An Evaluation of Space-Filling Information Visualizations for Depicting Hierarchical Structures

A variety of information visualization tools have been developed recently, but relatively little effort has been made to evaluate the effectiveness and utility of the tools. This article describes results from two empirical studies of two visualization tools for depicting hierarchies, in particular, computer file and directory structures. The two systems examined implement space-filling methodologies, one rectangular, the Treemap method, and one circular, the Sunburst method. Participants performed typical file/directory search and analysis tasks using the two tools. In general, performance trends favored the Sunburst tool with respect to correct task performance, particularly on initial use. Performance with Treemap tended to improve over time and use, suggesting a greater learning cost that was partially recouped over time. Each tool afforded somewhat different search strategies, which also appeared to influence performance. Finally, participants strongly preferred the Sunburst tool, citing better ability to convey structure and hierarchy