35. A system in support of information search, information extraction and information retrieval, comprising: a plurality of computing devices, a plurality of databases, each of which comprises a plurality of documents comprising a plurality of text strings; a knowledge database communicatively coupled to said devices via a network, said knowledge database comprising a set of semantic representations for each of said plurality of text strings; a search engine responsive to said computing devices adapted to receive a search string and identify a subset of documents from all of said pluralities of documents on said plurality of databases utilizing said semantic representations, and ranking said subset of documents in accordance with a degree of coherence between said search string and each document of said subset of documents.
35. A system in support of information search, information extraction and information retrieval, comprising: a plurality of computing devices, a plurality of databases, each of which comprises a plurality of documents comprising a plurality of text strings; a knowledge database communicatively coupled to said devices via a network, said knowledge database comprising a set of semantic representations for each of said plurality of text strings; a search engine responsive to said computing devices adapted to receive a search string and identify a subset of documents from all of said pluralities of documents on said plurality of databases utilizing said semantic representations, and ranking said subset of documents in accordance with a degree of coherence between said search string and each document of said subset of documents. 43. The search system of claim 35 , further comprising matching an advertisement to at least some of said semantic representations, and displaying said advertisement to a user of at least one of said computing devices.