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.

Several visualizations have emerged which attempt to visualize all or part of the World Wide Web. Those visualizations, however, fail to present the dynamically changing ecology of users and documents on the Web. We present new techniques for Web Ecology and Evolution Visualization (WEEV). Disk Trees represent a discrete time slice of the Web ecology. A collection of Disk Trees forms a Time Tube, representing the evolution of the Web over longer periods of time. These visualizations are intended to aid authors and webmasters with the production and organization of content, assist Web surfers making sense of information, and help researchers understand the Web. Keywords World Wide Web, visualization, log file analysis, temporal analysis, information ecologies, hypertext, documents.

Information has become interactive. Information visualization is the design and creation of interactive graphic depictions of information by combining principles in the disciplines of graphic design, cognitive science, and interactive computer graphics. As the volume and complexity of the data increases, users require more powerful visualization tools that allow them to more effectively explore large abstract datasets. This

Network-accessible multimedia databases, repositories, and libraries are proliferating at a rapid rate. A crucial problem for these repositories remains timely and appropriate document access. In this paper, we borrow a model from psychological research on human memory, which has long studied retrieval of memory items based on frequency and recency rates of past item occurrences. Specifically, the model uses frequency and recency rates of prior document accesses to predict future document requests. The model is illustrated by analyzing the log file of document accesses to the Georgia Institute of Technology World-Wide Web (WWW) database, a large multimedia repository exhibiting high access rates. Results show that the model predicts document access rates with a reliable degree of accuracy. We describe extensions to the basic approach that combine the recency and frequency analyses, and incorporate repository structure and document type. These results have implications for the formulati...

In the process of knowledge discovery, workers examine available information in order to make sense of it. By sensemaking, we mean interacting with and operating on the information with a variety of information processing mechanisms [3,18]. Previously, we introduced a concept that uses the spreadsheet metaphor with cells containing visualizations of complex data. In this paper, we extend and apply a cognitive model called "visual sensemaking" to the Visualization Spreadsheet. We use the task of making sense of a large Web site as a concrete example through out the paper for demonstration. Using a variety of visualization techniques, such as the Disk Tree and Cone Tree, we show that the interactions of the Visualization Spreadsheet help users draw conclusions from the overall relationships of the entire information set. Keywords Information visualization, Spreadsheet, Sensemaking, World Wide Web, Information ecologies, Log file analysis 1. Introduction A graphic is not "drawn" once ...

HTTP server log files provide Web site operators with substantial detail regarding the visitors to their sites. Interest in interpreting this data has spawned an active market for software packages that summarize and analyze this data, providing histograms, pie graphs, and other charts summarizing usage patterns. While useful, these summaries obscure useful information and restrict users to passive interpretation of static displays. Interactive visualizations can be used to provide users with greater abilities to interpret and explore web log data. By combining two-dimensional displays of thousands of individual access requests, color and size coding for additional attributes, and facilities for zooming and filtering, these visualizations provide capabilities for examining data that exceed those of traditional web log analysis tools. We introduce a series of interactive visualizations that can be used to explore server data across various dimensions. Possible uses of these visualizations are discussed, and difficulties of data collection, presentation, and interpretation are explored. Keywords World Wide Web, Web Site Design, Log File Analysis, Information Visualization, Human-Computer Interaction 1.

In this paper we describe how we are using the Hy + visualization system to visualize the portion of the World Wide Web explored during a browsing session. As the user browses, the Web browser communicates the URL and title of each document fetched as well as all the anchors contained in the document. Hy + displays graphically the history of the navigation and multiple views of the structure of that portion of the Web. Queries of the visual query language GraphLog can be issued at any time to query and reformat the visualizations. 1 Introduction Traditional Internet services and resources, such as email, telnet, ftp, gopher, and wais, have been used by the Internet community for years. It was only recently that a new Internet service, the World Wide Web came into existence on the Internet. Browsers for the Web provide a simple user interface to all Internet services and Web resources. These resources are hypermedia documents written in HTML (HyperText Markup Language) and provided...

In this paper, we present visualizations of parts of the network of documents comprising the World Wide Web. We describe how we are using the Hy + visualization system to visualize the portion of the World Wide Web explored during a browsing session. As the user browses, the web browser communicates the URL and title of each document fetched as well as all the anchors contained in the document. Hy + displays graphically the history of the navigation and multiple views of the structure of that portion of the web. 1 Introduction World Wide Web browsers allow users to navigate the web in a hypertext style by clicking on the labels of the anchors of HTML documents 1 . However, as the browser session progresses, the user may quickly get out of context; the lost in hyperspace problem. Overview diagrams of hyperspaces (or parts of them) have been recognized as important aids to help both orientation and navigation through the space [Nie95, UY89]. In this paper, we show how we can gene...

Previous studies of World-Wide Web traffic patterns have, quite necessarily, been limited in their scope. Without exception they have had to choose to represent either a client's [1] or a server's [2,3] point of view, or solicit user responses in interactive surveys [4,5]. In all of these cases the methodology is able to provide neither a complete nor an impartial picture of the activities being carried out on the Web. The unique position of the HENSA Unix proxy cache, sitting between large numbers of clients and servers, means that over the past two years we have been able to monitor and analyse several hundreds of millions of transactions on the World-Wide Web. In this paper we present our findings as far as traffic trends are concerned. These trends show both the growth of the Web and typical characteristics of a large volume of Web traffic. The configuration of the HENSA cache has changed significantly over the two years of its existence, and one of the purposes of this study is to...

In this paper, we present methods of information visualization that applies to the discovery of patterns in World-Wide Web sites. We hope to use techniques of information visualization to help in the organization and categorization of Web sites. We present a detailed case study of using the spreadsheet to analyze the content, usage, and structure of a large Web site. We demonstrate how the visualization spreadsheet principles apply in this specific data domain. 1 Introduction Currently, producers, organizers, and users of content on the World Wide Web must use technologies that are spartan in providing cues that would make their lives easier. For comparison, the librarian or experienced user of a physical library can usually tell, with some ease, the general layout of content, figure out which books are of greatest interest to the community (e.g., by the wear on the book spines), and figure out what's timely or deadwood (e.g., by looking at the circulation checkout stamps inside the ...