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).

With the growth of the Web, there has been a rapid increase in the number of users who need to access online databases without having a detailed knowledge of the schema or of query languages; even relatively simple query languages designed for non-experts are too complicated for them. We describe BANKS, a system which enables keyword-based search on relational databases, together with data and schema browsing. BANKS enables users to extract information in a simple manner without any knowledge of the schema or any need for writing complex queries. A user can get information by typing a few keywords, following hyperlinks, and interacting with controls on the displayed results. BANKS models tuples as nodes in a graph, connected by links induced by foreign key and other relationships. Answers to a query are modeled as rooted trees connecting tuples that match individual keywords in the query. Answers are ranked using a notion of proximity coupled with a notion of prestige of nodes based on inlinks, similar to techniques developed for Web search. We present an efficient heuristic algorithm for finding and ranking query results. 1.

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.

Conventional software systems, such as those based on the "desktop metaphor," are ill-equipped to manage the electronic information and events of the typical computer user. We introduce a new metaphor, Lifestreams, for dynamically organizing a user's personal workspace. Lifestreams uses a simple organizational metaphor, a time-ordered stream of documents, as an underlying storage system. Stream filters are used to organize, monitor and summarize information for the user. Combined, they provide a system that subsumes many separate desktop applications. This paper describes the Lifestreams model and our prototype system. I. Introduction I NEXPERIENCED users are right to be confused by today 's operating systems; they aren't well suited to most users needs and they require too many separate applications, too many file and format translations, the invention of too many pointless names and the construction of organizational hierarchies that too quickly become obsolete. They are built on id...

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.

The Information Visualization and Exploration Environment (IVEE) is a system for automatic creation of dynamic queries applications. IVEE imports database relations and automatically creates environments holding visualizations and query devices. IVEE offers multiple visualizations such as maps and starfields, and multiple query devices, such as sliders, alphasliders, and toggles. Arbitrary graphical objects can be attached to database objects in visualizations. Multiple visualizations may be active simultaneously. Users can interactively lay out and change between types of query devices. Users may retrieve details-on-demand by clicking on visualization objects. An HTML file may be provided along with the database, specifying how details-ondemand information should be presented, allowing for presentation of multimedia information in database objects. Finally, multiple IVEE clients running on separate workstations on a network can communicate by letting one users actions affect the visua...

Visualization of high-dimensional, large data sets, resulting from computational simulation, is one of the most challenging fields in scientific visualization. When visualization aims at supporting the analysis of such data sets, feature-based approaches are very useful to reduce the amount of data which is shown at each instance of time and guide the user to the most interesting areas of the data. When using feature-based visualization, one of the most difficult questions is how to extract or specify the features. This is mostly done (semi-)automatic up to now. Especially when interactive analysis of the data is the main goal of the visualization, tools supporting interactive specification of features are needed. In this paper we present a framework for flexible and interactive specification of high-dimensional and/or complex features in simulation data. The framework makes use of multiple, linked views from information as well as scientific visualization and is based on a simple and compact feature definition language (FDL). It allows the definition of one or several features, which can be complex and/or hierarchically described by brushing multiple dimensions (using non-binary and composite brushes). The result of the specification is linked to all views, thereby a focus+context style of visualization in 3D is realized. To demonstrate the usage of the specification, as well as the linked tools, applications from flow simulation in the automotive industry are presented.

We propose a rudimentary taxonomy of interactive data visualization based on a triad of data analytic tasks: finding Gestalt, posing queries, and making comparisons. These tasks are supported by three classes of nteractive view manipulation: focusing, linking and arranging views. This discussion extends earlier work on the principles of focusing and linking and sets them on a firmer base. Next, we give a high-level introduction to a particular system for multivariate data visualization: XGobi. This introduction is not comprehensive but emphasizes XGobi tools that are examples of focusing, linking and arranging views, namely: high-dimensional projections, linked scatterplot brusing, and matrices of conditional plots.

Direct manipulation user interfaces have proven their worth over two decades, but they are still in their youth. Dramatic opportunities exist to develop direct manipulation programming to create end-user programming tools, dynamic queries to perform information search in large databases, and information visualization to support network database browsing. Direct manipulation depends on visual representation of the objects and actions of interest, physical actions or pointing instead of complex syntax, and rapid incremental reversible operations whose effect on the object of interest is immediately visible. This strategy can lead to user interfaces that are comprehensible, predictable and controllable. Direct manipulation interfaces are seen as more likely candidates to influence advanced user interfaces than adaptive, autonomous, intelligent agents. User control and responsibility are highly desirable.

In this paper we review studies of the growth of the Internet and technologies that are useful for information search and retrieval on the Web. We present data on the Internet from several different sources, e.g., current as well as projected number of users, hosts, and Web sites. Although numerical figures vary, overall trends cited