The User as Navigator

The old idea of navigation in a database is revisited with two essential changes: we address Web users rather than programmers and the navigation is accomplished as a visual metaphor. The Structural Knowledge Graph Navigator (SKGN) is a prototype implementation of this metaphor. It supports end users of Web applications by simple means for ad hoc querying and browsing in an object-oriented database. The interface has been implemented within the European project ICONS. SKGN utilizes three core concepts: intentional navigation (in a schema graph), extensional navigation (in an object graph) and annotated user baskets for storing intermediate and final results of querying. The paper describes the motivation and main ideas of SKGN.