US 5,761,631 A · Parsing method and system for natural language processing

Abstract

The present invention provides a method and system to improve the accuracy of natural language processing systems by enabling them to acquire a parsing output that is accurate to a degree for any type of sentence. The feature of the present invention is that a sentence (a non-grammatical, ill-formed sentence) that cannot be parsed when using a conventional parsing process, which relies on grammatical knowledge, is re-analyzed by using the parsing results for an identical word row in a sentence (a well-formed sentence) in the same context that could be parsed. More specifically, the processing below is performed: (1) a well-formed sentence in a context that includes a word row that is identical to a word row in an ill-formed sentence is searched for, and a dependency structure for that word row is extracted from the parsing results for the well-formed sentence; and (2) the dependency structures of the phrases obtained in (1) are linked by referring to linking information for the well-formed sentence and a grammar, and the dependency structure of the entire sentence is introduced.

Claims22

Dependent claims

A computer implemented natural language analysis method, comprising the steps of:

(a) inputting a plurality of sentences described in natural language;
(b) analyzing said plurality of sentences into morphemes;
(c) parsing said plurality of sentences based on those results that are obtained by said morphological analysis;
(d) when those results that are obtained by said parsing are well-formed sentences, storing said parsing analysis results as well-formed context information;
(e) when those results that are obtained by said parsing are ill-formed sentences, storing said parsing analysis results as ill-formed sentence information;
(f) upon completion of said parsing of said plurality of sentences, retrieving, from said well-formed context information, partial parsing information for sentences having parsing analysis results that were stored as said ill-formed sentence information;
and
(g) parsing once more said sentences having parsing analysis results that were stored as said ill-formed sentence information by using said information retrieved from said well-formed context information.

5 more elements

A computer implemented natural language analysis system, comprising:

(a) means for inputting a plurality of sentences described in natural language;
(b) means for analyzing said plurality of sentences into morphemes;
(c) means for parsing said plurality of sentences based on those results that are obtained by said morphological analysis;
(d) means for, when said results of said parsing are well-formed sentences, storing, as well-formed context information, parsing information that includes information about word connections;
(e) means for, when the results of said parsing are ill-formed sentences, storing, as ill-formed sentence information, parsing information that includes information about word rows;
(f) means for, upon completion of said parsing of said plurality of sentences, retrieving, from said well-formed context information, information about a word row connection that is the same as each sentence having parsing information that was stored as said ill-formed sentence information;
(g) means for determining whether or not all words in a sentence having parsing information that was stored as said ill-formed sentence information are dominated by information that is retrieved from said well-formed context information, and if there are words that are not so dominated, extracting information for said words from said ill-formed sentence information;
(h) means for storing grammar information includes word connection rule;
and
(i) means for connecting phrase structure trees by applying said context information and grammar information stored in said storing means to information that is obtained from said retrieving means and said determining means.

7 more elements

Dependencies are inferred from the claim text.

Parsing method and system for natural language processing

Life of this patent

Parsing method and system for natural language processing

Life of this patent

Abstract

Claims22