Example

To illustrate how WebMap works, a simple example session is discussed in this section. Assume that the WWW client Mosaic is running and displaying the home page of the ``First International Conference on the World-Wide Web'' before WebMap was started. (The interaction scheme between Mosaic and WebMap is explained in section 3.3.)

The first node WebMap displays gets the number 0 (see Fig. 1). Nodes are displayed without full URL's because this would disturb the survey. They are numbered according to the time of their first access. The numbers may be used for identifying related documents using lists (see Table 1).

A faster and more convenient solution is, however, to move the mouse over a node (``touch it''; node 3 in Fig. 1). The Title and URL of the document are displayed immediately below the canvas. A double click on a node loads the corresponding document into one of Mosaic's windows.

The red node (node 0 in Fig. 1) is the current node, representing the document that is displayed in Mosaic's top window. The pink node (node 3 in Fig. 1 and node 5 in Fig. 2) is currently ``touched'' by the (invisible) mouse pointer.

WebMap categorizes edges to supply additional information about the document structure (see also section ). Green edges signal a jump to another http server (e.g., 01, i.e., www1.cern.chwww.cern.ch) to remind the user of a change in communication costs. If there is a path between two nodes consisting solely of black edges, the two corresponding pages are provided by the same http server (e.g., 0, 2, 3, 4, 6 in Fig. 2 by www1.cern.ch).

Dashed orange edges are some of the so-called ``non-tree-edges'' which indicate cross-jumps between spanning tree nodes provided by the same server (e.g., 36 in Fig. 2: The secretariat has been visited by the ``Call for Contribution'' page (node 2) and by the ``Committees'' page (node 6)).

Dashed blue edges are used to mark transitions between previously visited documents residing on different servers (e.g., 45, here there is no joining hyperlink in the connected documents: this edge results from a direct URL-jump).

To help the reader keep track of ``where he is'', WebMap provides a playback feature. First, the user chooses a history strategy (see page ) and gets a dialog box similar to Fig. 3. This dialog is derived from a special widget object. Dragging the left scale-slider moves the selection through the history list. Simultanously the node corresponding to the selected list item is highlighted in the graphical map. While the user drags the slider the nodes on the map are flashing up in the order defined by the history strategy thus visualizing the route through the web.

WebMap may also be used to automatically fetch and store each visited page in one or more selected formats, e.g., PostScript and HTML. A dialog similar to Fig. 3 is used to build and order subsets of visited documents to create print jobs.

Another useful feature is the possibility to store the whole map and to load it during another session. This way exploring a server or a paper the first time delivers a map which may be used as a navigational aid the next time this server or paper is visited.

Such a map is based on a user's personal way to explore a set of pages by following the contained links which often is based on random. However, it could be useful if the author of a set of pages provided a map together with his pages. Such a map would reflect the author's intentions and provide the optimal navigation structure. This topic is more deeply addressed in section 4.