Concept-based search and retrieval system

A method of performing a concept-based searching of text documents comprising the steps of:

• transforming a natural language query into predicate structures representing logical relationships between words in said natural language query;
• providing an ontology containing lexical semantic information about words;
• transforming said text documents into predicate structures;
• probabilistically classifying said document predicate structures and said query predicate structures;
• filtering said document predicate structures against said query predicate structures to produce a set of said document predicate structures matching said query predicate structures;
• and
• ranking said set of matching predicate structures.

An apparatus for use in an information retrieval system for retrieving information in response to a query, comprising:

• a query ontological parser that transforms a natural language query into predicate structures;
• an ontology providing information about words, said information comprising lexical semantic representation and syntactic types;
• a document ontological parser that transforms documents into predicate structures;
• a Bayes classifier probabilistically classifying said documents and said query;
• adaptive filters for filtering said documents against said query to produce a set of said documents matching said query;
• and
• a ranking module for ranking said set of matching documents.

An apparatus for use in an information retrieval system for retrieving information in response to a query comprising:

• a query ontological parser that transforms a natural language query into predicate structures;
• an ontology providing information about words, said information comprising syntactic uses and definitions;
• a document ontological parser that transforms documents into predicate structures;
• a Bayes classifier probabilistically classifying said documents and said query;
• adaptive filters for filtering said predicate structures of said documents against said predicate structures of said query to group said documents according to similarity of concept patterns contained in said documents relative to said query or additional feedback;
• and
• a ranking module for ranking said set of matching predicate structures.