The use of lexicons in information retrieval in legal databases

This paper reports on the mid-beta stage of development of the Flexicon system and descrii how a 1exicaUy designed search engine in a domain specific database such as a large database of legal cases, can provide better relevance ranking than best match search engines, and at the same time permit an information need to be formulated using multiple word concepts, phrases and items, which is the one great advantage that an exact match Boolean search engine has to offer over best match engines. In addition the paper sets out in detail the lexical structure of the Flexicon system. The first tests on a legal problem, comparing the Flexicon system with two best match systems, indicate that a lexkally designed search engine and database has the potential for a substantially higher level of precision than best match search engines.