Multiple viewpoints as an approach to digital library interfaces

A viewpoint is a representational scheme on some collection of data objects, together with a mechanism for accessing this content. A multiple viewpoint system allows a searcher to pose queries in one viewpoint and then change to another viewpoint while retaining a sense of context, taking advantage of the improvement in retrieval results given by using di erent relevance judgements and di erent representations together in a single information retrieval system (as observed by Wilbur [6] and Rajashekar and Croft [4]). The rst advantage of a multiple viewpoint system is in providing a larger vocabulary of usable query terms. Formulating a query e ectively depends on consistent use of vocabulary between the query and the document descriptions. A multiple viewpoint system can incorporate viewpoints that index the same collection in more than one vocabulary, accepting queries in either. A thesaurus which nds synonyms in other vocabularies is also an example of a viewpoint, and can further expand the usable query vocabulary. The most important characteristic of a multiple viewpoint system is the transition mapping between each pair of viewpoints, which represents interrelations between data elements. For instance, if the same book is described in general science vocabulary in one viewpoint and in medical jargon in another, the transition mapping would map between these two representations allowing a searcher who had found the book in one viewpoint to see what was considered most similar to the same book in the other viewpoint. Entirely di erent objects might also be associated by a transition mapping. If one viewpoint represented a document collection and another the relationships among a set