Information retrieval system with means for analyzing undefined words in a natural language inquiry

• US 4,994,967 A
• Filed: 01/11/1989
• Issued: 02/19/1991
• Est. Priority Date: 01/12/1988
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Asakawa, Satoshi
• Primary Examiner(s): Smith, Jerry
• Assistant Examiner(s): Kibby, Steven G.
• Application Number:
  US07/295,758
• Time in Patent Office: 769 Days
• Field of Search: 364/419
• US Class Current: 704/9
• CPC Class Codes: G06F 16/3329 Natural language query formulation or dialogue systems
• CPC Class Codes: G06F 40/30 Semantic analysis

Abstract

An information retrieval system is adapted to carry out information retrieval by entering an inquiry sentence in natural language, executing semantic analysis of the natural language inquiry sentence by a semantic analysis unit, and producing a retrieval condition from a result of the semantic analysis. The information retrieval system is provided in its semantic analysis unit with an undefined word processing unit which classifies an undefined word in the inquiry sentence in accordance with a process of producing a retrieval condition from the semantic analysis of other words contained in the inquiry sentence, the undefined word being defined as a word unregistered in a dictionary provided therein and incapable of direct semantic analysis, and displays a result of processing for the undefined word classified. The undefined word processing permits operation of information retrieval to be done without discontinuation.

Claims

1. In an information retrieval system adapted to perform information retrieval in response to an inquiry sentence inputted in natural language, by carrying out a semantic analysis of the natural language inquiry sentence by means of a semantic analysis unit, and by producing a retrieval condition from a result of said semantic analysis, the improvement comprising:

undefined word processing means for classifying an undefined word in the inputted inquiry sentence in accordance with a process of producing a retrieval condition from a semantic analysis of another word in the inquiry sentence, said undefined word being a word unregistered in a dictionary and incapable of direct semantic analysis; and

display processing means for displaying a message based on a result of classifying the undefined word by said undefined word processing means.

2. An information retrieval system adapted to perform information retrieval in response to an inquiry sentence inputted in natural language, by carrying out semantic analysis of the natural language inquiry sentence by means of a semantic analysis unit, and by producing a retrieval condition from a result of said semantic analysis, comprising:

an input unit for inputting an inquiry sentence in a natural language;

a semantic analysis unit for carrying out a semantic analysis of the inquiry sentence;

an undefined word processing unit for classifying an undefined word in the inputted inquiry sentence in accordance with a process of producing a retrieval condition from a semantic analysis of another word in the inquiry sentence, said undefined word being incapable of direct semantic analysis; and

display processing means for displaying a message based on a result of classifying the undefined word by said undefined word processing unit.

3. An information retrieval system as claimed in claim 2, wherein the semantic analysis unit contains a dictionary and means for carrying out a semantic analysis in conjunction with the dictionary to define a word unregistered in the dictionary, and wherein the undefined word processing unit operates to process the undefined word.

4. An information retrieval system adapted to perform information retrieval in response to an inquiry sentence inputted in natural language, by carrying out semantic analysis of the natural language inquiry sentence by means of a semantic analysis unit, and by producing a retrieval condition from a result of said semantic analysis, comprising:

an input unit for inputting an inquiry sentence in natural language;

a semantic analysis unit for carrying out a semantic analysis of the inquiry sentence;

an undefined word processing unit for classifying an undefined word in the inputted inquiry sentence in accordance with a process of producing a retrieval condition from a semantic analysis of another word in the inquiry sentence, said undefined word being incapable of direct semantic analysis;

display processing means for producing a message based on a result of classifying the undefined word by said undefined word processing unit;

a data base unit for storing information to be retrieved;

a data base retrieving unit for retrieving data from said data base unit in response to the retrieval condition produced by said undefined word processing unit; and

a display unit for displaying a result of processing by said display processing means and a result of retrieval by said data base retrieving unit.

5. A method for processing an undefined word in an information retrieval system adapted to perform information retrieval in response to an inquiry sentence inputted in natural language, by carrying out a semantic analysis of the natural language inquiry sentence by means of a semantic analysis unit, and by producing a retrieval condition from a result of said semantic analysis, comprising:

an input step of inputting the inquiry sentence in natural language;

a semantic analysis step of carrying out a semantic analysis of the inquiry sentence;

a step of classifying an undefined word in the inputted inquiry sentence in accordance with a process of producing a retrieval condition from a semantic analysis of another word in the inquiry sentence, said undefined word being a word unregistered in a dictionary and incapable of semantic analysis; and

a step of displaying a message based on a result of classifying the undefined word.