ben @ cs.umd.edu A useful starting point for designing advanced graphical user interjaces is the Visual lnformation-Seeking Mantra: overview first, zoom and filter, then details on demand. But this is only a starting point in trying to understand the rich and varied set of information visualizations that have been proposed in recent years. This paper offers a task by data type taxonomy with seven data types (one-, two-, three-dimensional datu, temporal and multi-dimensional data, and tree and network data) and seven tasks (overview, Zoom, filter, details-on-demand, relate, history, and extracts). Everything points to the conclusion that the phrase 'the language of art ' is more

We present a new focus+context (fisheye) technique for visualizing and manipulating large hierarchies. Our technique assigns more display space to a portion of the hierarchy while still embedding it in the context of the entire hierarchy. The essence of this scheme is to lay out the hierarchy in a uniform way on a hyperbolic plane and map this plane onto a circular display region. This supports a smooth blending between focus and context, as well as continuous redirection of the focus. We have developed effective procedures for manipulating the focus using pointer clicks as well as interactive dragging, and for smoothly animating transitions across such manipulation. A laboratory experiment comparing the hyperbolic browser with a conventional hierarchy browser was conducted.

The World Wide Web is a large, heterogeneous, distributed collection of documents connected by hypertext links. The most common technology currently used for searching the Web depends on sending information retrieval requests to "index servers" that index as many documents as they can find by navigating the network. One problem with this is that users must be aware of the various index servers (over a dozen of them are currently deployed on the Web), of their strengths and weaknesses, and of the peculiarities of their query interfaces. A more serious problem is that these queries cannot exploit the structure and topology of the document network. In this paper we propose a query language, WebSQL, that takes advantage of multiple index servers without requiring users to know about them, and that integrates textual retrieval with structure and topology-based queries. We give a formal semantics for WebSQL using a calculus based on a novel "virtual graph" model of a document network. We propose a new theory of query cost based on the idea of "query locality," that is, how much of the network must be visited to answer a particular query. We give an algorithm for characterizing WebSQL queries with respect to query locality. Finally, we describe a prototype implementation of WebSQL written in Java.

This article provides a taxonomy of distortion-oriented techniques which demonstrates clearly their underly- ng relationships. A unified theory is presented to reveal their roots and origins. Issues relating to the implementation and performance of these techniques are also discussed

A fisheye camera lens is a very wide angle lens that magnifies nearby objects while shrinking distant objects. It is a valuable tool for seeing both "local detail" and "global context" simultaneously. This paper describes a system for viewing and browsing graphs using a software analog of a fisheye lens. We first show how to implement such a view using solely geometric transformations. We then describe a more general transformation that allows global information about the graph to affect the view. Our general transformation is a fundamental extension to previous research in fisheye views. Categories and Subject Descriptors: D.2.2 [Software Engineering]: Tools and Techniques--User Interfaces H.5.2 [Information Interfaces and Presentation]: User Interfaces--Interaction styles I.3.6 [Computer Graphics]: Methodology and Techniques--Interaction Techniques General Terms: Visualization Additional Key Words and Phrases: Fisheye Views, Graph Layout, Information Visualization, Interactive Gra...

Software is invisible, disappearing into files on disks. The invisible nature of software contributes to low programmer productivity by hiding system complexity, particularly for large team-oriented projects. Visualization can help software engineers cope with this complexity and thereby increase programmer productivity. We describe four innovative visual representations of software that scale to productionsized systems and illustrate their usage in five software case studies involving: version history, differencing, static properties, performance profiles, and dynamic program slices. Keywords: software visualization, legacy code, version history, program comparison, profiling, slicing. 1 Introduction It is well known that large computer programs are complex and difficult to maintain. Production-sized systems, particularly legacy software, may contain millions of lines of code. Even a seemingly simple, small-team software project, such as a spreadsheet, is very complicated [CE94]. ...

This paper describes an experiment comparing two methods for viewing hierarchically clustered networks. Traditional full-zoom techniques provide details of only the current level of the hierarchy. In contrast fisheye views, generated by the "variable zoom" algorithm described in this paper, provides information about higher levels as well. Subjects using both viewing methods were given problem solving tasks requiring them to navigate a network, in this case a simulated telephone system, and to reroute links in it. Results suggest that the greater context provided by fisheye views significantly improved a user's performance of the tasks. They were quicker to complete their task, and they made fewer unnecessary navigational steps through the hierarchy. This validation of fisheye views is important for designers of interfaces to complicated monitoring systems, such as control rooms for supervisory control and data acquisition systems, where efficient human performance is often critical. However, control room operators remained concerned about the size and visibility tradeoffs between the fine detail provided by full-zooms, and the global context supplied by fisheye views. Specific interface features are required to reconcile the differences.

We present a novel tree browser that builds on the conventional node link tree diagrams. It adds dynamic rescaling of branches of the tree to best fit the available screen space, optimized camera movement, and the use of preview icons summarizing the topology of the branches that cannot be expanded. In addition, it includes integrated search and filter functions. This paper reflects on the evolution of the design and highlights the principles that emerged from it. A controlled experiment showed benefits for navigation to already previously visited nodes and estimation of overall tree topology.

We present a new focus context (fisheye) scheme for visualizing and manipulating large hierarchies. The essence of our approach is to lay out the hierarchy uniformly on the hyperbolic plane and map this plane onto a circular display region. The projection onto the disk provides a natural mechanism for assigning more space to a portion of the hierarchy while still embedding it in a much larger context. Change of focus is accomplished by translating the structure on the hyperbolic plane, which allows a smooth transition without compromising the presentation of the context. KEYWORDS: Hierarchy Display, Information Visualization, Fisheye Display, Focus Context Technique.

. An extension to the treemap method for the visualization of hierarchical information, such as directory structures and organization structures, is presented. The standard treemap method often gives thin, elongated rectangles. As a result, rectangles are difficult to compare and to select. A new method is presented to generate lay-outs in which the rectangles approximate squares. To strenghten the visualization of the structure, shaded frames are used around groups of related nodes. 1 Introduction Hierarchical structures of information are everywhere: directory structures, organization structures, family trees, catalogues, computer programs, and so on. Small hierarchical structures are effective to locate information, but the content and organization of large structures is harder to grasp. We present a new visualization method for large hierarchical structures: Squarified Treemaps. The method is based on Treemaps, developed by Shneiderman and Johnson [9, 6]. Treemaps are effic...