From Hierarchies to Networks

This chapter highlights moves away from the strict hierarchies of traditional taxonomy to models where metadata is viewed more as a network. Facetted classification, proposed by the Indian librarian S.R. Ranganathan in the 1930s, offers a new way for simple concepts to be combined into more complex subjects with great flexibility. More recently ontologies, ways of expressing complex semantic relationships between concepts in machine-readable form, have become important in information science.