Highlighting in Information Visualization: A Survey
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paper_title: A Rank-by-Feature Framework for Interactive Exploration of Multidimensional Data

paper_content:

Interactive exploration of multidimensional data sets is challenging because: (1) it is difficult to comprehend patterns in more than three dimensions, and (2) current systems often are a patchwork of graphical and statistical methods leaving many researchers uncertain about how to explore their data in an orderly manner. We offer a set of principles and a novel rank-by-feature framework that could enable users to better understand distributions in one (1D) or two dimensions (2D), and then discover relationships, clusters, gaps, outliers, and other features. Users of our framework can view graphical presentations (histograms, boxplots, and scatterplots), and then choose a feature detection criterion to rank 1D or 2D axis-parallel projections. By combining information visualization techniques (overview, coordination, and dynamic query) with summaries and statistical methods users can systematically examine the most important 1D and 2D axis-parallel projections. We summarize our Graphics, Ranking, and Interaction for Discovery (GRID) principles as: (1) study 1D, study 2D, then find features (2) ranking guides insight, statistics confirm. We implemented the rank-by-feature framework in the Hierarchical Clustering Explorer, but the same data exploration principles could enable users to organize their discovery process so as to produce more thorough analyses and extract deeper insights in any multidimensional data application, such as spreadsheets, statistical packages, or information visualization tools.
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paper_title: Supporting Visual Queries on Medium-Sized Node–Link Diagrams

paper_content:

For reasons of clarity, a typical node-link diagram statically displayed on paper or a computer screen contains fewer than 30 nodes. However, many problems would benefit if far more complex information could be diagrammed. Following Munzner et al., we suggest that with interactive diagrams this may be possible. We describe an interactive technique whereby a subset of a larger network diagram is highlighted by being set into oscillatory motion when a node is selected with a mouse. The subset is determined by a breadth first search of the underlying graph starting from the selected node. This technique is designed to support visual queries on moderately large node-link diagrams containing up to a few thousand nodes. An experimental evaluation was carried out with networks having 32, 100, 320, 1000, and 3200 nodes respectively, and with four highlighting techniques: static highlighting, motion highlighting, static + motion highlighting, and none. The results show that the interactive highlighting methods support rapid visual queries of nodes in close topological proximity to one another, even for the largest diagrams tested. Without highlighting, error rates were high even for the smallest network that was evaluated. Motion highlighting and static highlighting were equally effective. A second experiment was carried out to evaluate methods for showing two subsets of a larger network simultaneously in such a way that both are clearly distinct. The specific task was to determine if the two subsets had nodes in common. The results showed that this task could be performed rapidly and with few errors if one subset was highlighted using motion and the other was highlighted using a static technique. We discuss the implications for information visualization.
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paper_title: A focus+context visualization technique using semi-transparency

paper_content:

This paper describes a new 2D focus+context visualization technique for viewing and navigating large hierarchical information. This technique uses a semi-transparency approach to display both the global and the detail views of the hierarchy with an overlapped manner in the same display space. The twin views always keep one in highlighted and another in deemphasized, and this state can be shifted interactively when a user focuses on other view. The main advantage of this technique is that there is no geometrical partitioning required and both the context view and the focus view can use the full display space. To achieve the smooth transactions between the views, animation is accommodated to preserver user's mental map during the navigation. Although this visualization technique can theoretically be applied to many layout algorithms, we only apply this technique, in our implementation, for viewing and navigating hierarchies that are drawn by ENCCON (Nguyen and Huang, 2004) layout algorithm.
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paper_title: High Dimensional Brushing for Interactive Exploration of Multivariate Data

paper_content:

Brushing is an operation found in many data visualization systems. It is a mechanism for interactively selecting subsets of the data so that they may be highlighted, deleted, or masked. Traditionally, brushes have been defined in screen space via methods such as painting and rubberband rectangles. In this paper we describe the design of N-dimensional brushes which are defined in data space rather than screen space, and show how they have been integrated into XmdvTool, a visualization package for displaying multivariate data. Depending on the data display technique in use, brushes may be specified and manipulated via direct or indirect methods, and the specification may be demand-driven or data-driven. Various brush operations such as highlighting, linking, masking, moving average, and quantitative display have been developed to apply to the selected data. In addition, we have explored several new brush concepts, such as non-discrete brush boundaries, simultaneous display of multiple brushes, and creating composite brushes via logical operators. Preliminary experimental evaluation with test subjects supports the usefulness of N-dimensional brushes in data exploration tasks.
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paper_title: Semantic depth of field

paper_content:

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.
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paper_title: Thread Arcs: an email thread visualization

paper_content:

This paper describes Thread Arcs, a novel interactive visualization technique designed to help people use threads found in email. Thread Arcs combine the chronology of messages with the branching tree structure of a conversational thread in a mixed-model visualization by Venolia and Neustaedter (2003) that is stable and compact. By quickly scanning and interacting with Thread Arcs, people can see various attributes of conversations and find relevant messages in them easily. We tested this technique against other visualization techniques with users' own email in a functional prototype email client. Thread Arcs proved an excellent match for the types of threads found in users' email for the qualities users wanted in small-scale visualizations.
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paper_title: Motion to support rapid interactive queries on node--link diagrams

paper_content:

Many different problems can be represented as graphs displayed in the form of node--link diagrams. However, when a graph is large it becomes visually uninterpretable because of the tangle of links. We describe a set of techniques that use motion in an interactive interface to provide effective access to larger graphs. Touching a node with the mouse cursor causes that node and the subgraph of closely connected nodes to oscillate. We argue from perceptual principles that this should be a more effective way of interactively highlighting a subgraph than more conventional static methods. The MEGraph system was developed to gain experience with different forms of motion highlighting. Based on positive feedback, three experiments were carried out to evaluate the effectiveness of motion highlighting for specific tasks. All three showed motion to be more effective than static highlighting, both in increasing the speed of response for a variety of visual queries, and in reducing errors. We argue that motion highlighting can be a valuable technique in applications that require users to understand large graphs.
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paper_title: Filtering and Brushing with Motion

paper_content:

Visualizing information in user interfaces to complex, large-scale systems is difficult due to visual fragmentation caused by an enormous amount of inter-related data distributed across multiple views. New display dimensions are required to help the user visually integrate and filter such spatially distributed and heterogeneous information. Motion holds promise in this regard as a perceptually efficient display dimension. It has long been known to have a strong grouping effect, suggesting it has potential for filtering and brushing techniques. However, there is little known about which properties of motion are most effective. This paper reviews the prior literature relating to the use of motion for display and discusses the requirements for how motion can be usefully applied to these problems, especially for visualizations incorporating multiple groups of data objects. Results from previous research by the authors suggested motion type was a strong distinguishing feature. Three types of motions in pairwise combinations were compared: linear, circular and expansion/contraction. Combinations of linear directions were also compared to evaluate how great angular separation needs to be to enforce perceptual distinction. The results showed that motion can effectively group objects that are otherwise dissimilar. Type differentiation is more effective than directional differences (except for 90°). Of the three types studied, circular demands the most attention. Angular separation must be 90° to be equally effective. These results suggest that motion can be usefully applied to both filtering and brushing. They also provide the beginnings of a vocabulary of simple motions that can be applied to information visualization.
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paper_title: A Visualization Approach for Frauds Detection in Financial Market

paper_content:

The traditional solutions to the stock market security are not sufficient in identifying attackers and further attack plans from the analysis of existing events.Therefore, it is difficult for analysts to prevent future unexpected events or frauds by only monitoring the realtime trading information. The event-driven fraud detection in financial market could not help analysts to find attack plans and the further intention of attackers. This paper proposed a new framework of visual analytics for stock market security. The proposed solution consists of two stages: 1) Visual Surveillance of Market Performance, and 2) Behavior-Driven Visual Analysis of Trading Networks.In the first stage, we use a 3D treemaps to monitor the real-time stock market performance and to identify a particular stock that produced an unusual trading pattern. We then move to the next stage: social network visualization to conduct behavior-driven visual analysis of suspected pattern. Through the visual analysis of social (or trading)network, analysts may finally identify the attackers (the sources of the fraud), and further attack plans.
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paper_title: An evaluation of content browsing techniques for hierarchical space-filling visualizations

paper_content:

Space-filling visualizations, such as the TreeMap, are well suited for displaying the properties of nodes in hierarchies. To browse the contents of the hierarchy, the primary mode of interaction is by drilling down through many successive layers. In this paper we introduce a distortion algorithm based on fisheye and continuous zooming techniques for browsing data in the TreeMap representation. The motivation behind the distortion approach is for assisting users to rapidly browse information displayed in the TreeMap without opening successive layers of the hierarchy. Two experiments were conducted to evaluate the new approach. In the first experiment (N=20) the distortion approach is compared to the drill down method. Results show that subjects are quicker and more accurate in locating targets of interest using the distortion method. The second experiment (N=12) evaluates the effectiveness of the two approaches in a task requiring context, we define as the context browsing task. The results show that subjects are quicker and more accurate in locating targets with the distortion technique in the context browsing task.
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paper_title: Focus+context display and navigation techniques for enhancing radial, space-filling hierarchy visualizations

paper_content:

Radial, space-filling visualizations can be useful for depicting information hierarchies, but they suffer from one major problem. As the hierarchy grows in size, many items become small, peripheral slices that are difficult to distinguish. We have developed three visualization/interaction techniques that provide flexible browsing of the display. The techniques allow viewers to examine the small items in detail while providing context within the entire information hierarchy. Additionally, smooth transitions between views help users maintain orientation within the complete information space.
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paper_title: Information Slices: Visualising and Exploring Large Hierarchies using Cascading, Semi-Circular Discs

paper_content:

This paper presents work in progress on a new technique for visu- alising and manipulating large hierarchies. The information slices approach compactly visualises hierarchical structures using a series of semi-circular discs. The technique is described in the context of our early experience with a prototype file system visualiser based on information slices. Over the last few years, the emerging field of information visuali- sation has resulted in a numerous techniques for helping visualise and make sense of large information spaces (10). Among these are several techniques for visualising and interacting with large hierar- chies which go beyond the traditional approach taken in 2d scrolling browsers such as the Windows Explorer. Treemaps (6, 9) are space-filling visualisations of hierarchies based on successive horizontal and vertical subdivision of screen rectangles. The area of each rectangle is proportional to some at- tribute of the underlying hierarchy such as the (total) size of each subtree. Xdu (4) is a utility for the X window system which displays a graphical disk usage for Unix file systems. Rectangles are stacked from left to right as the directory tree is descended. The current di- rectory is represented by the leftmost rectangle, which is the entire height of the window. Subdirectories are represented by neighbour- ing rectangles in the next column, whose height are proportional to the size of each subdirectory. The hyperbolic browser (7) uses a focus and context technique based on hyperbolic geometry. A hierarchy is laid out uniformly on the hyperbolic plane and then mapped to the unit disc for display on screen. Nodes in the centre of the disc are largest and nodes are assigned progressively less space towards the perimeter of the disc. Cheops (3) is based on multiple re-use of overlaid triangles in the display. Working top-down, the selection of a node (triangle) at a particular level designates that node's children are to be represented
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paper_title: A Visualization Approach for Frauds Detection in Financial Market

paper_content:

The traditional solutions to the stock market security are not sufficient in identifying attackers and further attack plans from the analysis of existing events.Therefore, it is difficult for analysts to prevent future unexpected events or frauds by only monitoring the realtime trading information. The event-driven fraud detection in financial market could not help analysts to find attack plans and the further intention of attackers. This paper proposed a new framework of visual analytics for stock market security. The proposed solution consists of two stages: 1) Visual Surveillance of Market Performance, and 2) Behavior-Driven Visual Analysis of Trading Networks.In the first stage, we use a 3D treemaps to monitor the real-time stock market performance and to identify a particular stock that produced an unusual trading pattern. We then move to the next stage: social network visualization to conduct behavior-driven visual analysis of suspected pattern. Through the visual analysis of social (or trading)network, analysts may finally identify the attackers (the sources of the fraud), and further attack plans.
---
paper_title: A focus+context visualization technique using semi-transparency

paper_content:

This paper describes a new 2D focus+context visualization technique for viewing and navigating large hierarchical information. This technique uses a semi-transparency approach to display both the global and the detail views of the hierarchy with an overlapped manner in the same display space. The twin views always keep one in highlighted and another in deemphasized, and this state can be shifted interactively when a user focuses on other view. The main advantage of this technique is that there is no geometrical partitioning required and both the context view and the focus view can use the full display space. To achieve the smooth transactions between the views, animation is accommodated to preserver user's mental map during the navigation. Although this visualization technique can theoretically be applied to many layout algorithms, we only apply this technique, in our implementation, for viewing and navigating hierarchies that are drawn by ENCCON (Nguyen and Huang, 2004) layout algorithm.
---
paper_title: A focus+context visualization technique using semi-transparency

paper_content:

This paper describes a new 2D focus+context visualization technique for viewing and navigating large hierarchical information. This technique uses a semi-transparency approach to display both the global and the detail views of the hierarchy with an overlapped manner in the same display space. The twin views always keep one in highlighted and another in deemphasized, and this state can be shifted interactively when a user focuses on other view. The main advantage of this technique is that there is no geometrical partitioning required and both the context view and the focus view can use the full display space. To achieve the smooth transactions between the views, animation is accommodated to preserver user's mental map during the navigation. Although this visualization technique can theoretically be applied to many layout algorithms, we only apply this technique, in our implementation, for viewing and navigating hierarchies that are drawn by ENCCON (Nguyen and Huang, 2004) layout algorithm.
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Title: Highlighting in Information Visualization: A Survey
Section 1: INTRODUCTION
Description 1: This section should introduce the concept of highlighting in information visualization, discuss the varied definitions over time, and present the paper's objective to redefine and elaborate on the role of highlighting.

Section 2: THE CONCEPTUAL MODEL OF HIGHLIGHTING
Description 2: This section should describe the proposed conceptual model, which consists of three layers: viewing control, interaction control, and visual recommendation.

Section 3: Viewing Control for Information Overloading
Description 3: This section should explain the function of viewing control, addressing the problem of information overload through techniques like color and light differentiation.

Section 4: Interaction Control for Information Retrieval
Description 4: This section should discuss the navigation control aspect, detailing how highlighting aids in guiding users through interactive visualization processes.

Section 5: Visual Recommendation for Decision Making
Description 5: This section should elaborate on how highlighting can be used in knowledge visualization and visual analytics to assist decision-makers by providing graphical recommendations.

Section 6: THE ELEMENTS OF HIGHLIGHTING
Description 6: This section should analyze the basic elements of highlighting, including differentiation in light, size, shape, presentation, and motion.

Section 7: FUTURE WORK & CONCLUSION
Description 7: This section should conclude the paper, highlighting the need for further exploration of highlighting theory and suggesting future research directions to expand the application and understanding of highlighting in information visualization.