In Intermedia, a hypertext system developed at Brown University, a web is defined as a network of documents or portions of documents linked together. Initially, the designers provided users with Web Views (similar to graphical browsers) called global map, local map, and local tracking map. A global map displayed every document in a web and the links between them. However, a global map worked well only with small webs. The local map was useful in focusing on the document of interest and its neighboring documents. The local tracking map dynamically updated the focus as documents were opened and activated.
Studies showed that the global map and the local tracking map were not of much use to users. Disoriented users need a sense of context and location. The need was felt to display no only spatial information ("Where can I go from here ?") but also temporal information ("How did I get here ?") [Utting & Yankelovich,1989]. The Web Views were modified to provide both spatial and temporal context in a flexible and non-intrusive manner. Three navigation tools were developed: a path, a map, and a scope line. Most often users would like to know, in advance, the amount of material in the web. This would help them decide whether to continue reading a document or to return later. The scope line informs the user about the number of documents and links in the web. Paths and maps are discussed in other sections.