Due to the scaling problems with explicitly authored links between information items, it is likely that future large scale hypertexts will employ a mixture of authored links and indirect, computed links via some form of indexing system. Problems of information access are heightened by the lack of precision of current WWW retrieval technology and users unfamiliar with indexing conventions. There is a critical need for tools that will assist users to formulate and refine queries, and navigate through information spaces.
Semantic indexing provides a bridge between the various information disciplines.
Another approach, the one followed here, includes a semantic index layer in its model of hypermedia architecture. In addition to explicitly authored links, each information item is indexed with descriptor terms - frequently more than one term will be required. Different types of indexing system are possible. The latter allows the possibility of 'false positives' where items are returned that have no connection between different terms in the source string. This allows the possibility of flexible query-based navigation tools.