Abstract
Since many XML documents do not contain any schema definition, we expected that there will be also RDF documents without RDF schema or ontology. Then the data can only be viewed as a general labeled directed graph and the idea to present the data to the user by drawing the graph seems natural.
We have developed a triangle layout algorithm for this. Because the data can be extremely large, it is impossible to display the whole graph at one time.
This makes incremental navigation a good choice. Only a suitable start node is displayed and the rest of the graph can be explored by incremental navigation.
By combining out 'node merging' technique and animations, the navigation is easy to use and follow. This way, we get a tool that can give the user good idea about structure and content of the data.