User needs determine what functions should be provided, and different functions require different structures. - Brian Campbell Vickery

The representation of knowledge in symbolic form is a matter that has pre-occupied the world of documentation since its origin. The problem is now relevant in many situations other than documents and indexes. The structure of records and files in databases: data structures in computer programming; the syntactic and semantic structure of natural language; knowledge representation in artificial intelligence; models of human memory: in all these fields it is necessary to decide how knowledge may be represented so that the representations may be manipulated.

The problems of subject search on the Internet are no different in principle: search engines may permit easy location of verbally expressed topics, but we still seek to improve our methods of navigation.

In seeking scientific understanding of the processes of information transfer we have had to go considerably outside the subject limits within which 'information science' as an academic subject is normally constrained... It has become increasingly clear that only by widening its “knowledge base” can information science establish a solid foundation for future development.