DevLan/vispubs huggingface dataset:
A comparison of 2-D visualizations of hierarchies
Authors: S. Todd Barlow, Padraic Neville
Published at InfoVis, 2001

This paper describes two experiments that compare four two-dimensional visualizations of hierarchies: organization chart, icicle plot, treemap, and tree ring. The visualizations are evaluated in the context of decision tree analyses prevalent in data mining applications. The results suggest that either the tree ring or icicle plot is equivalent to the organization chart.
An empirical comparison of three commercial information visualization systems
Authors: Alfred Kobsa
Published at InfoVis, 2001

An empirical comparison of three commercial information visualization systems on three different databases is presented. The systems use different paradigms for visualizing data. Tasks were selected to be "ecologically relevant", i.e. meaningful and interesting in the respec- tive domains. Users of one system turned out to solve problems significantly faster than users of the other two, while users of another system would supply significantly more correct answers. Reasons for these results and general observations about the studied systems are discussed.
Animated exploration of dynamic graphs with radial layout
Authors: Ka-Ping Yee, Danyel Fisher, Rachna Dhamija, Marti A. Hearst
Published at InfoVis, 2001

We describe a new animation technique for supporting interactive exploration of a graph. We use the well-known radial tree layout method, in which the view is determined by the selection of a focus node. Our main contribution is a method for animating the transition to a new layout when a new focus node is selected. In order to keep the transition easy to follow, the animation linearly interpolates the polar coordinates of the nodes, while enforcing ordering and orientation constraints. We apply this technique to visualizations of social networks and of the Gnutella file-sharing network, and discuss the results from our informal usability tests.
Botanical visualization of huge hierarchies
Authors: Ernst Kleiberg, Huub van de Wetering, Jarke J. van Wijk
Published at InfoVis, 2001

A new method for the visualization of huge hierarchical data structures is presented. The method is based on the observation that we can easily see the branches, leaves and their arrangement in a botanical tree, despite of the large number of elements. The strand model of Holton is used to convert an abstract tree into a geometric model. Non-leaf nodes are mapped to branches and child nodes to sub-branches. A naive application of this model leads to unsatisfactory results, hence it is tailored to suit our purposes better. Continuing branches are emphasized, long branches are contracted, and sets of leaves are shown as fruit. The method is applied to the visualization of directory structures. The elements, directories and files, as well as their relations can easily be extracted, thereby showing that the use of methods from botanical modeling can be effective for information visualization.
Case study: design and assessment of an enhanced geographic information system for exploration of multivariate health statistics
Authors: Robert M. Edsall, Alan M. MacEachren, Linda Pickle
Published at InfoVis, 2001

An implementation of an interactive parallel coordinate plot linked with the ArcView(r) geographic information system (GIS) is presented. The integrated geographic visualization system was created for the exploratory analysis of mortality data from specific cancers as they relate, specifically spatially, to other mortality causes and to demographic and socioeconomic risk factors. The linked and interactive parallel coordinate plot was tested with and compared to a similarly interactive and linked scatterplot in usability assessments designed to assess each representation's relative effectiveness for exploration of these data sets. Evidence from these studies suggests that multivariate, spatial, and/or time series exploration is enhanced through the use of the parallel coordinate plot linked to maps.
Case study: e-commerce clickstream visualization
Authors: Jeffrey Brainerd, Barry G. Becker
Published at InfoVis, 2001

We have developed an interactive, scalable visualization tool for analyzing the behavior of users of a web site. Our system not only shows site topology and traffic flow, but by segmenting site traffic data based on user attributes, including demographic data and purchase history, we can present a more complete picture of web site usage. This can lead to a more focussed analysis that allows direct comparison between user segments, and ultimately a deeper understanding of how users interact with a site. The tool is designed for real world use, and we present a usage study of the tool by analyzing the data of a failed "dot-com".
Case study: visualization for decision tree analysis in data mining
Authors: S. Todd Barlow, Padraic Neville
Published at InfoVis, 2001

Decision trees are one of the most popular methods of data mining. Decision trees partition large amounts of data into smaller segments by applying a series of rules. Creating and evaluating decision trees benefits greatly from visualization of the trees and diagnostic measures of their effectiveness. This paper describes an application, EMTree Results Viewer, that supports decision tree analysis through the visualization of model results and diagnosis. The functionality of the application and the visualization techniques are revealed through an example of churn analysis in the telecommunications industry.
Change blindness in information visualization: a case study
Authors: Lucy T. Nowell, Elizabeth G. Hetzler, Ted Tanasse
Published at InfoVis, 2001

Change blindness occurs when people do not notice changes in visible elements of a scene. If people use an information visualization system to compare document collection subsets partitioned by their time-stamps, change blindness makes it impossible for them to recognize even very major changes, let alone minor ones. We describe theories from cognitive science that account for the change blindness phenomenon, as well as solutions developed for two visual analysis tools, a dot plot (SPIRE Galaxies) and landscape (ThemeView(tm)) visualizations.
Cluster stability and the use of noise in interpretation of clustering
Authors: George S. Davidson, Brian N. Wylie, Kevin W. Boyack
Published at InfoVis, 2001

A clustering and ordination algorithm suitable for mining extremely large databases, including those produced by microarray expression studies, is described and analyzed for stability. Data from a yeast cell cycle experiment with 6000 genes and 18 experimental measurements per gene are used to test this algorithm under practical conditions. The process of assigning database objects to an X,Y coordinate, ordination, is shown to be stable with respect to random starting conditions, and with respect to minor perturbations in the starting similarity estimates. Careful analysis of the way clusters typically co-locate, versus the occasional large displacements under different starting conditions are shown to be useful in interpreting the data. This extra stability information is lost when only a single cluster is reported, which is currently the accepted practice. However, it is believed that the approaches presented here should become a standard part of best practices in analyzing computer clustering of large data collections.
Collapsible cylindrical trees: a fast hierarchical navigation technique
Authors: Raimund Dachselt, Jürgen Ebert
Published at InfoVis, 2001

This paper proposes a new visualization and interaction technique for medium-sized trees, called Collapsible Cylindrical Trees (CCT). Child nodes are mapped on rotating cylinders, which will be dynamically displayed or hidden to achieve a useful balance of detail and context. Besides a comprehensible three-dimensional visualization of trees, the main feature of CCT is a very fast and intuitive interaction with the displayed nodes. Only a single click is needed to reach every node and perform an action on it, such as displaying a web page. The CCT browsing technique was developed for interaction with web hierarchies but is not limited to this domain. We also present sample implementations of CCT using VRML, which show the usefulness of this intuitive tree navigation technique.
Effective graph visualization via node grouping
Authors: Janet M. Six, Ioannis G. Tollis
Published at InfoVis, 2001

We discuss four methodologies for the application of node grouping in graph visualization. In addition, we introduce techniques for force-directed and orthogonal drawing which use node grouping information and have been shown in experiments to perform better than previous techniques. Not only do these techniques have significantly improved performance with respect to standard aesthetic measures, but they also attain qualitative improvement.
Getting along: composition of visualization paradigms
Authors: Alan Keahey
Published at InfoVis, 2001

This paper describes how focus+context techniques can be composed with other high-level visualization paradigms to mutual advantage. Examples are given showing composition both with a pan\&zoom system, and with a treemap implementation. The examples illustrate how focus+context can be used as an exploration and navigation tool within those paradigms.
Graph sketches
Authors: James Abello, Irene Finocchi, Jeffrey L. Korn
Published at InfoVis, 2001

We introduce the notion of Graph Sketches. They can be thought of as visual indices that guide the navigation of a multi-graph too large to fit on the available display. We adhere to the Visual Information-Seeking Mantra: Overview first, zoom and filter, then details on demand. Graph Sketches are incorporated into MGV, an integrated visualization and exploration system for massive multi-digraph navigation. We highlight the main algorithmic and visualization tasks behind the computation of Graph Sketches and illustrate several application scenarios. Graph Sketches will be used to guide the navigation of multi-digraphs defined on vertex sets with sizes ranging from 100 to 250 million vertices.
Graphic data display for cardiovascular system
Authors: James Agutter, Noah Syroid, Frank Drews, Dwayne R. Westenskow, Julio C. Bermudez, David L. Strayer
Published at InfoVis, 2001

Our multi-disciplinary group has developed a visual representation for cardiovascular physiological variables. This enhances a clinician’s ability to detect and rapidly respond to critical events. The integrated and intuitive display communicates a patient’s cardiovascular state so that it is easily and quickly understood without prior training. The display is designed to show patterns of functional relationships that aid in the detection, diagnosis, and treatment of a critical event.
Interactive visualization of multiple query results
Authors: Susan L. Havre, Elizabeth G. Hetzler, Kenneth A. Perrine, Elizabeth Jurrus, Nancy Miller
Published at InfoVis, 2001

This paper introduces a graphical method for visually presenting and exploring the results of multiple queries simultaneously. This method allows a user to visually compare multiple query result sets, explore various combinations among the query result sets, and identify the "best" matches for combinations of multiple independent queries. This approach might also help users explore methods for progressively improving queries by visually comparing the improvement in result sets.
Ordered treemap layouts
Authors: Ben Shneiderman, Martin Wattenberg
Published at InfoVis, 2001

Treemaps, a space-filling method of visualizing large hierarchical data sets, are receiving increasing attention. Several algorithms have been proposed to create more useful displays by controlling the aspect ratios of the rectangles that make up a treemap. While these algorithms do improve visibility of small items in a single layout, they introduce instability over time in the display of dynamically changing data, and fail to preserve an ordering of the underlying data. This paper introduces the ordered treemap, which addresses these two shortcomings. The ordered treemap algorithm ensures that items near each other in the given order will be near each other in the treemap layout. Using experimental evidence from Monte Carlo trials, we show that compared to other layout algorithms ordered treemaps are more stable while maintaining relatively favorable aspect ratios of the constituent rectangles. A second test set uses stock market data.
Pixel bar charts: a new technique for visualizing large multi-attribute data sets without aggregation
Authors: Daniel A. Keim, Ming C. Hao, Julian Ladisch, Meichun Hsu, Umeshwar Dayal
Published at InfoVis, 2001

Simple presentation graphics are intuitive and easy-to-use, but show only highly aggregated data and present only a very limited number of data values (as in the case of bar charts). In addition, these graphics may have a high degree of overlap which may occlude a significant portion of the data values (as in the case of the x-y plots). In this paper, we therefore propose a generalization of traditional bar charts and x-y-plots which allows the visualization of large amounts of data. The basic idea is to use the pixels within the bars to present the detailed information of the data records. Our so-called pixel bar charts retain the intuitiveness of traditional bar charts while allowing very large data sets to be visualized in an effective way. We show that, for an effective pixel placement, we have to solve complex optimization problems, and present an algorithm which efficiently solves the problem. Our application using real-world e-commerce data shows the wide applicability and usefulness of our new idea.
Semantic depth of field
Authors: Robert Kosara, Silvia Miksch, Helwig Hauser
Published at InfoVis, 2001

We present a new technique called Semantic Depth of Field (SDOF) as an alternative approach to focus-and-context displays of information. We utilize a well-known method from photography and cinematography (depth-of-field effect) for information visualization, which is to blur different parts of the depicted scene in dependence of their relevance. Independent of their spatial locations, objects of interest are depicted sharply in SDOF, whereas the context of the visualization is blurred. In this paper, we present a flexible model of SDOF which can be easily adopted to various types of applications. We discuss pros and cons of the new technique, give examples of application, and describe a fast prototype implementation of SDOF.
Technical note: visually encoding program test information to find faults in software
Authors: James R. Eagan, Mary Jean Harrold, James A. Jones, John T. Stasko
Published at InfoVis, 2001

Large test suites are frequently used to evaluate software systems and to locate errors. Unfortunately, this process can generate a huge amount of data that is difficult to interpret manually. We have created a system, Tarantula, that visually encodes test data to help find program errors. The system uses a principled color mapping to represent source lines in passed and failed tests. It also provides a flexible user interface for examining different perspectives that show the behavior of the source code on test sets, ranging from individual tests, to important subsets such as the set of failed tests, to the entire test suite.
To draw a tree
Authors: Pat Hanrahan
Published at InfoVis, 2001

The quintessential goal of information visualization is depicting abstractions and relations for non-spatial data. A hierarchy is a particularly expressive abstraction that can be applied to a broad range of domains: the genealogical lineages of human descent, the functional decomposition of complex mechanical objects, the classification of knowledge, the evolutionary relationships between species. All of these hierarchical relationships are representable through the abstraction of a recursively defined tree. For this reason, trees occupy a place along with arrays, lists and graphs as one of the most important data structures in computer science. Considering the simple problem of how to effectively draw a tree uncovers many issues fundamental to information visualization. Different drawing styles emphasize different properties of trees, often in subtle ways. I will discuss how people think about trees, and thus what kinds of relationships a tree drawing can usefully convey. My discussion will include a review of many methods for drawing trees, including both historical examples from the sciences and techniques recently developed by researchers in information visualization.
Visualization of state transition graphs
Authors: Frank van Ham, Huub van de Wetering, Jarke J. van Wijk
Published at InfoVis, 2001

A new method for the visualization of state transition graphs is presented. Visual information is reduced by clustering nodes, forming a tree structure of related clusters. This structure is visualized in three dimensions with concepts from cone trees and emphasis on symmetry. The resulting visualization makes it easier to relate features in the visualization of the state transition graph to semantic concepts in the corresponding process and
Visualizing time-series on spirals
Authors: Marc Weber, Marc Alexa, Wolfgang Müller 0004
Published at InfoVis, 2001

In this paper, we present a new approach for the visualization of time-series data based on spirals. Different to classical bar charts and line graphs, the spiral is suited to visualize large data sets and supports much better the identification of periodic structures in the data. Moreover, it supports both the visualization of nominal and quantitative data based on a similar visualization metaphor. The extension of the spiral visualization to 3D gives access to concepts for zooming and focusing and linking in the data set. As such, spirals complement other visualization techniques for time series and specifically enhance the identication of periodic patterns.
3D or not 3D? evaluating the effect of the third dimension in a document management system
Authors: Andy Cockburn, Bruce J. McKenzie
Published at CHI, 2001

Several recent research systems have provided interactive three-dimensional (3D) visualisations for supporting everyday work such as file and document management. But what improvements do these 3D interfaces offer over their traditional 2D counterparts? This paper describes the comparative evaluation of two document management systems that differ only in the number of dimensions used for displaying and interacting with the data. The 3D system is heavily based on Robertson et al.'s Data Mountain, which supports users in storing, organising and retrieving “thumbnail” representations of documents such as bookmarked Web-pages. Results show that our subjects were faster at storing and retrieving pages in the display when using the 2D interface, but not significantly so. As expected, retrieval times significantly increased as the number of thumbnails increased. Despite the lack of significant differences between the 2D and 3D interfaces, subjective assessments showed a significant preference for the 3D interface.
Digital family portraits: supporting peace of mind for extended family members
Authors: Elizabeth D. Mynatt, Jim Rowan, Sarah Craighill, Annie Jacobs
Published at CHI, 2001

A growing social problem in the U.S., and elsewhere, is supporting older adults who want to continue living independently, as opposed to moving to an institutional care setting. One key part of this complex problem is providing awareness of senior adults day-to-day activities, promoting peace of mind for extended family members. In this paper, we introduce the concept of a digital family portrait that provides qualitative visualizations of a family members daily life. Leveraging a familiar household object, the picture frame, our design populates the frame with iconic imagery summarizing 28 days. In a final implementation, the digital family portrait would gather information from sensors in the home.
Information scent as a driver of Web behavior graphs: results of a protocol analysis method for Web usability
Authors: Stuart K. Card, Peter Pirolli, Mija M. Van Der Wege, Julie Bauer Morrison, Robert W. Reeder, Pamela K. Schraedley, Jenea Boshart
Published at CHI, 2001

The purpose of this paper is to introduce a replicable WWW protocol analysis methodology illustrated by application to data collected in the laboratory. The methodology uses instrumentation to obtain detailed recordings of user actions with a browser, caches Web pages encoutered, and videotapes talk-aloud protocols. We apply the current form of the method to the analysis of eight Web protocols, visualizing the structure of the interaction and showing the strong effect of information scent in determining the path followed.
Visual information foraging in a focus + context visualization
Authors: Peter Pirolli, Stuart K. Card, Mija M. Van Der Wege
Published at CHI, 2001

Eye tracking studies of the Hyperbolic Tree browser [10] suggest that visual search in focus+context displays is highly affected by information scent (i.e., local cues, such as text summaries, used to assess and navigate toward distal information sources). When users detected a strong information scent, they were able to reach their goal faster with the Hyperbolic Tree browser than with a conventional browser. When users detected a weak scent or no scent, users exhibited less efficient search of areas with a high density of visual items. In order to interpret these results we present an integration of the CODE Theory of Visual Attention (CTVA) with information foraging theory. Development of the CTVA-foraging theory could lead to deeper analysis of interaction with visual displays of content, such as the World Wide Web or information visualizations.
Visualization components for persistent conversations
Authors: Marc A. Smith, Andrew T. Fiore
Published at CHI, 2001

An appropriately designed interface to persistent, threaded conversations could reinforce socially beneficial behavior by prominently featuring how frequently and to what degree each user exhibits such behaviors. Based on the data generated by the Netscan data-mining project [9], we have developed a set of tools for illustrating the structure of discussion threads like those found in Usenet newsgroups and the patterns of participation within the discussions. We describe the benefits and challenges of integrating these tools into a multi-faceted dashboard for navigating and reading discussions in social cyberspaces like Usenet and related interaction media. Visualizations of the structure of online discussions have applications for research into the sociology of online groups as well as possible interface designs for their members.
3D digital cleansing using segmentation rays
Authors: Sarang Lakare, Ming Wan, Mie Sato, Arie E. Kaufman
Published at Vis, 2000

We propose a novel approach for segmentation and digital cleansing of endoscopic organs. Our method can be used for a variety of segmentation needs with little or no modification. It aims at fulfilling the dual and often conflicting requirements of a fast and accurate segmentation and also eliminates the undesirable partial volume effect which contemporary approaches cannot. For segmentation and digital cleansing, we use the peculiar characteristics exhibited by the intersection of any two distinct-intensity regions. To detect these intersections we cast rays through the volume, which we call the segmentation rays as they assist in the segmentation. We then associate a certain task of reconstruction and classification with each intersection the ray detects. We further use volumetric contrast enhancement to reconstruct surface lost by segmentation (if any), which aids in improving the quality of the volume rendering.