OLIVE: Network



The goal of network information visualization involves gaining insight into a structure that may consist of many data items. Networks consists of nodes and links, nodes representing a data point, and a link representing a relationship between two nodes. Much of the early work done in this field came about from graph drawing. A graph with few points (or vertices) is easy to draw and to comprehend visually, but currently tools are needed to handled large data sets. Large set of data tend to have much of their information hidden. Finding a structure or hierarchy among a set of data points is not easy, therefore many are categorized into different cases of networks (acyclic, lattices, rooted versus unrooted, directed versus undirected). This enables researchers to develop algorithms to perform tasks on these structures such as finding the shortest or least costly paths connecting two items or traversing the entire network.

A diagram of a network is often used to illustrate the structure of a network. Most interface representations include the following kinds of node-and-link diagrams: two-dimensional or three-dimensional. Some visualization techniques add animation, distortion, and tightly-coupled overview window to reveal even more information about a network.

Although network visualization goes back to the 1960's (Tutte, 1963, Knuth, 1963) the representation is still an imperfect art. The sheer complexity of relationships and user tasks that can exist leaves much work to be done. Commercial packages can handle small networks or simple strategies, such as Netmap's layout of nodes on a circle with links criss-crossing the central area. Specialized visualizations can be designed to be more effective for a given task, such as a network diagram showing heavy telephone traffic on holidays. An ambitious three-dimensional approach allowed users to fly into a network and control the visualization (Fairchild et al., 1988). New interest in this topic has been spawned by attempts to visualize the World Wide Web (Andrews, 1995; Hendley et al., 1995, Munzner and Buchard, 1995).

Application areas of network visualization include databases (both the database model and items in the database), software (static connection of modules, classes; dynamic connection of processes; etc.), computer networks, World Wide Web as well as hypertext/hypermedia in general, digital library (references, etc.), GIS (geographic relations between locations), social and management networks, as well as everyday life (grocery shopping), etc.






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Last modified: Fri Jan 2 13:06:47 EST 1998 - {rjones,zzj}@cs.umd.edu