Multi-stage recognition of named entities in natural language text based on morphological and semantic features

Abstract

Systems and methods for multi-stage recognition of named entities based on morphological and semantic features of natural language texts. An example method comprises: performing a lexico-morphological analysis of a natural language text comprising a plurality of tokens, each token comprising at least one natural language word; determining, based on the lexico-morphological analysis, one or more lexical meanings and grammatical meanings associated with each token of the plurality of tokens; for each token the plurality of tokens, evaluating one or more classifier functions using the lexical and grammatical meanings associated with the tokens, wherein a value of each classifier function is indicative of a degree of association of the token with a category of named entities; performing a syntactico-semantic analysis of at least part of the natural language text to produce a plurality of semantic structures representing the part of the natural language text; and interpreting the semantic structures using a set of production rules to determine, for one or more tokens comprised by the part of the natural language text, a degree of association of the token with a category of named entities.