DevLan/vispubs huggingface dataset:
The Gödel Engine - An interactive approach to visualization in general relativity
Authors: Frank Grave, Thomas Müller 0005, Carsten Dachsbacher, Günter Wunner
Published at EuroVis, 2009

We present a methodical new approach to visualize the aspects of general relativity from a self‐centered perspective. We focus on the visualization of the Gödel universe, which is an exact solution to Einstein's field equations of general relativity. This model provides astounding features such as the existence of an optical horizon and the possibility of time travel. Although we know that our universe is not of Gödel type, we can – using this solution to Einstein's equations – visualize and understand the effects resulting from the theory of relativity, which itself has been verified on the large scale in numerous experiments over the last century. We derive the analytical solution to the geodesic equations of Gödel's universe for special initial conditions. Along with programmable graphics hardware we achieve a tremendous speedup for the visualization of general relativity. This enables us to interactively explore the physical aspects and optical effects of Gödel's universe. We also demonstrate how the analytical solution enables dynamic lighting with local illumination models. Our implementation is tailored for Gödel's universe and five orders of magnitude faster than previous approaches. It can be adapted to manifolds for which an analytical expression of the propagation of light is available.
Visual Analysis of Brain Activity from fMRI Data
Authors: Firdaus Janoos, Boonthanome Nouanesengsy, Raghu Machiraju, Han-Wei Shen, Steffen Sammet, Michael V. Knopp, István Ákos Mórocz
Published at EuroVis, 2009

Classically, analysis of the time‐varying data acquired during fMRI experiments is done using static activation maps obtained by testing voxels for the presence of significant activity using statistical methods. The models used in these analysis methods have a number of parameters, which profoundly impact the detection of active brain areas. Also, it is hard to study the temporal dependencies and cascading effects of brain activation from these static maps. In this paper, we propose a methodology to visually analyze the time dimension of brain function with a minimum amount of processing, allowing neurologists to verify the correctness of the analysis results, and develop a better understanding of temporal characteristics of the functional behaviour. The system allows studying time‐series data through specific volumes‐of‐interest in the brain‐cortex, the selection of which is guided by a hierarchical clustering algorithm performed in the wavelet domain. We also demonstrate the utility of this tool by presenting results on a real data‐set.
Visualisation of Sensor Data from Animal Movement
Authors: Edward Grundy, Mark W. Jones, Robert S. Laramee, Rory P. Wilson, Emily L. C. Shepard
Published at EuroVis, 2009

A new area of biological research is identifying and grouping patterns of behaviour in wild animals by analysing data obtained through the attachment of tri‐axial accelerometers. As these recording devices become smaller and less expensive their use has increased. Currently acceleration data are visualised as 2D time series plots, and analyses are based on summary statistics and the application of Fourier transforms. We develop alternate visualisations of this data so as to analyse, explore and present new patterns of animal behaviour. Our visualisations include interactive spherical scatterplots, spherical histograms, clustering methods, and feature‐based state diagrams of the data. We study the application of these visualisation methods to accelerometry data from animal movement. The reaction of biologists to these visualisations is also reported.
Visualization of vessel movements
Authors: Niels Willems, Huub van de Wetering, Jarke J. van Wijk
Published at EuroVis, 2009

We propose a geographical visualization to support operators of coastal surveillance systems and decision making analysts to get insights in vessel movements. For a possibly unknown area, they want to know where significant maritime areas, like highways and anchoring zones, are located. We show these features as an overlay on a map. As source data we use AIS data: Many vessels are currently equipped with advanced GPS devices that frequently sample the state of the vessels and broadcast them. Our visualization is based on density fields that are derived from convolution of the dynamic vessel positions with a kernel. The density fields are shown as illuminated height maps. Combination of two fields, with a large and small kernel provides overview and detail. A large kernel provides an overview of area usage revealing vessel highways. Details of speed variations of individual vessels are shown with a small kernel, highlighting anchoring zones where multiple vessels stop. Besides for maritime applications we expect that this approach is useful for the visualization of moving object data in general.
Visualization Techniques for Schedule Comparison
Authors: Dandan Huang, Melanie Tory, Sheryl Staub-French, Rachel Pottinger
Published at EuroVis, 2009

Project schedules are effectively represented by Gantt charts, but comparing multiple versions of a schedule is difficult. To compare versions with current methods, users must search and navigate through multiple large documents, making it difficult to identify differences. We present two novel visualization techniques to support the comparison of Gantt charts. First, we encode two Gantt charts in one view by overlapping them to show differences. Second, we designed an interactive visual technique, the ‘TbarView’, that allows users to compare multiple schedules within one single view. We evaluated the overlap and TbarView techniques via a user study. The study results showed that our design provided a quick overview of the variances among two or more schedules, and the techniques also improved efficiency by minimizing view switching. Our visual techniques for schedule comparison could be combined with other resource analysis tools to help project teams identify and resolve errors and problems in project schedules.
Visualizing the Evolution of Compound Digraphs with TimeArcTrees
Authors: Martin Greilich, Michael Burch, Stephan Diehl 0001
Published at EuroVis, 2009

Compound digraphs are a widely used model in computer science. In many application domains these models evolve over time. Only few approaches to visualize such dynamic compound digraphs exist and mostly use animation to show the dynamics. In this paper we present a new visualization tool called TimeArcTrees that visualizes weighted, dynamic compound digraphs by drawing a sequence of node‐link diagrams in a single view. Compactness is achieved by aligning the nodes of a graph vertically. Edge crossings are reduced by drawing upward and downward edges separately as colored arcs. Horizontal alignment of the instances of the same node in different graphs facilitates comparison of the graphs in the sequence. Many interaction techniques allow to explore the given graphs. Smooth animation supports the user to better track the transitions between views and to preserve his or her mental map. We illustrate the usefulness of the tool by looking at the particular problem of how shortest paths evolve over time. To this end, we applied the system to an evolving graph representing the German Autobahn and its traffic jams.
Volume Deformations in Grid-Less Flow Simulations
Authors: Harald Obermaier, Martin Hering-Bertram, Jörg Kuhnert, Hans Hagen
Published at EuroVis, 2009

This paper presents a novel method for the extraction and visualization of volume deformations in grid‐less point based flow simulations. Our primary goals are the segmentation of different paths through a mixing device and the visualization of ellipsoidal particle deformations. The main challenges are the numerically efficient processing of deformation tensors and the robust integration of stream‐ and streaklines at boundaries of the dataset such that closed segments are obtained. Our results show two‐ and three‐dimensional particle deformations as well as the segmentation of volumes in stationary fields and areas in time‐dependent datasets taking consistent paths through a mixing device.
A user study on visualizing directed edges in graphs
Authors: Danny Holten, Jarke J. van Wijk
Published at CHI, 2009

Graphs are often visualized using node-link representations: vertices are depicted as dots, edges are depicted as (poly)lines connecting two vertices. A directed edge running from vertex A to B is generally visualized using an arrow representation: a (poly)line with a triangular arrowhead at vertex B. Although this representation is intuitive, it is not guaranteed that a user is able to determine edge direction as quickly and unambiguously as possible; alternative representations that exhibit less occlusion and visual clutter might be better suited. To investigate this, we developed five additional directed-edge representations using combinations of shape and color. We performed a user study in which subjects performed different tasks on a collection of graphs using these representations and combinations thereof to investigate which representation is best in terms of speed and accuracy. We present our initial hypotheses, the outcome of the user studies, and recommendations regarding directed-edge visualization.
An intuitive model of perceptual grouping for HCI design
Authors: Ruth Rosenholtz, Nathaniel R. Twarog, Nadja Schinkel-Bielefeld, Martin Wattenberg
Published at CHI, 2009

Understanding and exploiting the abilities of the human visual system is an important part of the design of usable user interfaces and information visualizations. Good design enables quick, easy and veridical perception of key components of that design. An important facet of human vision is its ability to seemingly effortlessly perform "perceptual organization; it transforms individual feature estimates into perception of coherent regions, structures, and objects. We perceive regions grouped by proximity and feature similarity, grouping of curves by good continuation, and grouping of regions of coherent texture. In this paper, we discuss a simple model for a broad range of perceptual grouping phenomena. It takes as input an arbitrary image, and returns a structure describing the predicted visual organization of the image. We demonstrate that this model can capture aspects of traditional design rules, and predicts visual percepts in classic perceptual grouping displays.
Conversation clusters: grouping conversation topics through human-computer dialog
Authors: Tony Bergstrom, Karrie Karahalios
Published at CHI, 2009

Conversation Clusters explores the use of visualization to highlight salient moments of live conversation while archiving a meeting. Cheaper storage and easy access to recording devices allows extensive archival. However, as the size of the archive grows, retrieving the desired moments becomes increasingly difficult. We approach this problem from a socio-technical perspective and utilize human intuition aided by computer memory. We present computationally detected topics of conversation as visual summaries of discussion and as reference points into the archive. To further bootstrap the system, humans can participate in a dialog with the visualization of the clustering process and shape the development of clustering models.
Creating a spoken impact: encouraging vocalization through audio visual feedback in children with ASD
Authors: Joshua M. Hailpern, Karrie Karahalios, James Halle
Published at CHI, 2009

One hallmark difficulty of children with Autism Spectrum Disorder (ASD) centers on communication and speech. Research into computer visualizations of voice has been shown to influence conversational patterns and allow users to reflect upon their speech. In this paper, we present the Spoken Impact Project (SIP), an effort to examine the effect of audio and visual feedback on vocalizations in low-functioning children with ASD by providing them with additional means of understanding and exploring their voice. This research spans over 12 months, including the creation of multiple software packages and detailed analysis of more than 20 hours of experimental video. SIP demonstrates the potential of computer generated audio and visual feedback to encourage vocalizations of children with ASD.
EnsembleMatrix: interactive visualization to support machine learning with multiple classifiers
Authors: Justin Talbot, Bongshin Lee, Ashish Kapoor, Desney S. Tan
Published at CHI, 2009

Machine learning is an increasingly used computational tool within human-computer interaction research. While most researchers currently utilize an iterative approach to refining classifier models and performance, we propose that ensemble classification techniques may be a viable and even preferable alternative. In ensemble learning, algorithms combine multiple classifiers to build one that is superior to its components. In this paper, we present EnsembleMatrix, an interactive visualization system that presents a graphical view of confusion matrices to help users understand relative merits of various classifiers. EnsembleMatrix allows users to directly interact with the visualizations in order to explore and build combination models. We evaluate the efficacy of the system and the approach in a user study. Results show that users are able to quickly combine multiple classifiers operating on multiple feature sets to produce an ensemble classifier with accuracy that approaches best-reported performance classifying images in the CalTech-101 dataset.
FacetLens: exposing trends and relationships to support sensemaking within faceted datasets
Authors: Bongshin Lee, Greg Smith, George G. Robertson, Mary Czerwinski, Desney S. Tan
Published at CHI, 2009

Previous research has shown that faceted browsing is effective and enjoyable in searching and browsing large collections of data. In this work, we explore the efficacy of interactive visualization systems in supporting exploration and sensemaking within faceted datasets. To do this, we developed an interactive visualization system called FacetLens, which exposes trends and relationships within faceted datasets. FacetLens implements linear facets to enable users not only to identify trends but also to easily compare several trends simultaneously. Furthermore, it offers pivot operations to allow users to navigate the faceted dataset using relationships between items. We evaluate the utility of the system through a description of insights gained while experts used the system to explore the CHI publication repository as well as a database of funding grant data, and report a formative user study that identified usability issues.
Fisheyes in the field: using method triangulation to study the adoption and use of a source code visualization
Authors: Mikkel Rønne Jakobsen, Kasper Hornbæk
Published at CHI, 2009

Information visualizations have been shown useful in numerous laboratory studies, but their adoption and use in real-life tasks are curiously under-researched. We present a field study of ten programmers who work with an editor extended with a fisheye view of source code. The study triangulates multiple methods (experience sampling, logging, thinking aloud, and interviews) to describe how the visualization is adopted and used. At the concrete level, our results suggest that the visualization was used as frequently as other tools in the programming environment. We also propose extensions to the interface and discuss features that were not used in practice. At the methodological level, the study identifies contributions distinct to individual methods and to their combination, and discusses the relative benefits of laboratory studies and field studies for the evaluation of information visualizations.
PhotoScope: visualizing spatiotemporal coverage of photos for construction management
Authors: Fuqu Wu, Melanie Tory
Published at CHI, 2009

PhotoScope visualizes the spatiotemporal coverage of photos in a photo collection. It extends the standard photo browsing paradigm in two main ways: visualizing spatial coverage of photos, and indexing photos by a combination of spatial coverage, time, and content specifications. This approach enables users to browse and search space- and time-indexed photos more effectively. We designed PhotoScope specifically to address challenges in the construction management industry, where large photo collections are amassed to document project progress. These ideas may also apply to any photo collection that is spatially constrained and must be searched using spatial, temporal, and content criteria. We describe the design choices made when developing PhotoScope and the results of user evaluation.
PrintMarmoset: redesigning the print button for sustainability
Authors: Jun Xiao, Jian Fan
Published at CHI, 2009

In this paper, we discuss some unique challenges of sustainable interaction design (SID) and present our work that aims to reduce paper waste from web printing. We conducted a two-month field study of current behaviors and attitudes around printing, and the results confirmed the affordances of paper, but also revealed many problems associated with printing web content. We then designed and implemented a browser extension, PrintMarmoset, that targets these problems while simultaneously addressing user needs and environmental responsibility. It allows users to effortless select or remove web content for printing. We have also incorporated a data sharing mechanism into our solution to assist in the adoption of the tool and created visualizations to encourage user reflection and exploration.
SiteLens: situated visualization techniques for urban site visits
Authors: Sean White, Steven Feiner
Published at CHI, 2009

Urban designers and urban planners often conduct site visits prior to a design activity to search for patterns or better understand existing conditions. We introduce SiteLens, an experimental system and set of techniques for supporting site visits by visualizing relevant virtual data directly in the context of the physical site, which we call situated visualization. We address alternative visualization representations and techniques for data collection, curation, discovery, comparison, manipulation, and provenance. A real use scenario is presented and two iterations of evaluation with faculty and students from the Columbia University Graduate School of Architecture, Planning and Preservation provide directions and insight for further investigation.
Sizing the horizon: the effects of chart size and layering on the graphical perception of time series visualizations
Authors: Jeffrey Heer, Nicholas Kong, Maneesh Agrawala
Published at CHI, 2009

We investigate techniques for visualizing time series data and evaluate their effect in value comparison tasks. We compare line charts with horizon graphs - a space-efficient time series visualization technique - across a range of chart sizes, measuring the speed and accuracy of subjects' estimates of value differences between charts. We identify transition points at which reducing the chart height results in significantly differing drops in estimation accuracy across the compared chart types, and we find optimal positions in the speed-accuracy tradeoff curve at which viewers performed quickly without attendant drops in accuracy. Based on these results, we propose approaches for increasing data density that optimize graphical perception.
So you know you're getting the best possible information: a tool that increases Wikipedia credibility
Authors: Peter Pirolli, Evelin Wollny, Bongwon Suh
Published at CHI, 2009

An experiment was conducted to study how credibility judgments about Wikipedia are affected by providing users with an interactive visualization (WikiDashboard) of article and author editing history. Overall, users who self-reported higher use of Internet information and higher rates of Wikipedia usage tended to produce lower credibility judgments about Wikipedia articles and authors. However, use of WikiDashboard significantly increased article and author credibility judgments, with effect sizes larger than any other measured effects of background media usage and attitudes on Wikiepedia credibility. The results suggest that increased exposure to the editing/authoring histories of Wikipedia increases credibility judgments.
Topology-aware navigation in large networks
Authors: Tomer Moscovich, Fanny Chevalier, Nathalie Henry, Emmanuel Pietriga, Jean-Daniel Fekete
Published at CHI, 2009

Applications supporting navigation in large networks are used every days by millions of people. They include road map navigators, flight route visualization systems, and network visualization systems using node-link diagrams. These applications currently provide generic interaction methods for navigation: pan-and-zoom and sometimes bird's eye views. This article explores the idea of exploiting the connection information provided by the network to help navigate these large spaces. We visually augment two traditional navigation methods, and develop two special-purpose techniques. The first new technique, called "Link Sliding", provides guided panning when continuously dragging along a visible link. The second technique, called "Bring & Go", brings adjacent nodes nearby when pointing to a node. We compare the performance of these techniques in both an adjacency exploration task and a node revisiting task. This comparison illustrates the various advantages of content-aware network navigation techniques. A significant speed advantage is found for the Bring & Go technique over other methods.
Unravelling seams: improvoing mobile gesture recognition with visual feedback techniques
Authors: Sven G. Kratz, Rafael Ballagas
Published at CHI, 2009

Gesture recognition is emerging as an engaging interaction technique in mobile scenarios, and high recognition rates promote user acceptance. Several factors influence recognition rates including the nature of the gesture set and the suitability of the gesture recognition algorithm. This work explores how seamfulness in gesture stroke visualization affects recognition rates. We present the results of a user evaluation of a gesture recognition system that shows that raw (seamful) visualization of low-delity gesture stroke data has recognition rates comparable to no feedback. Providing filtered (seamless) stroke visualization to the user, while retaining the un-filtered input data for recognition, resulted in a 34.9% improvement in gesture recognition rate over raw stroke data. The results provide insights into the broader design space of seamful design, and identifies areas where seamlessness is advantageous.
Visualizing real-time language-based feedback on teamwork behavior in computer-mediated groups
Authors: Gilly Leshed, Diego Perez, Jeffrey T. Hancock, Dan Cosley, Jeremy P. Birnholtz, Soyoung Lee, Poppy L. McLeod, Geri Gay
Published at CHI, 2009

While most collaboration technologies are concerned with supporting particular tasks such as workflows or meetings, many work groups do not have the teamwork skills essential to effective collaboration. One way to improve teamwork is to provide dynamic feedback generated by automated analyses of behavior, such as language use. Such feedback can lead members to reflect on and subsequently improve their collaborative behavior, but might also distract from the task at hand. We have experimented with GroupMeter - a chat-based system that presents visual feedback on team members' language use. Feedback on proportion of agreement words and overall word count was presented using two different designs. When receiving feedback, teams in our study expressed more agreement in their conversations and reported greater focus on language use as compared to when not receiving feedback. This suggests that automated, real-time linguistic feedback can elicit behavioral changes, offering opportunities for future research.