Knowledge based information retrieval system

• US 5,404,506 A
• Filed: 02/10/1992
• Issued: 04/04/1995
• Est. Priority Date: 03/27/1985
• Status: Expired due to Term

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Hatakeyama, Atsushi, Cohn, David, Fujisawa, Hiromichi, Kiuchi, Itsuko
• Primary Examiner(s): Kriess, Kevin A.
• Assistant Examiner(s): Chavis, John Q.
• Application Number:
  US07/831,093
• Time in Patent Office: 1,149 Days
• Field of Search: 395/600
• US Class Current: 1/1
• CPC Class Codes: G06F 16/3338 Query expansion
• CPC Class Codes: G06F 16/93 Document management systems
• CPC Class Codes: G06F 40/211 Syntactic parsing, e.g. based on context-free grammar [CFG] or unification grammars
• CPC Class Codes: G06F 40/284 Lexical analysis, e.g. tokenisation or collocates
• CPC Class Codes: G06F 40/30 Semantic analysis
• CPC Class Codes: G06T 11/206 Drawing of charts or graphs
• CPC Class Codes: Y10S 706/934 Information retrieval or Information management
• CPC Class Codes: Y10S 707/99934 Query formulation, input preparation, or translation
• CPC Class Codes: Y10S 707/99935 Query augmenting and refining, e.g. inexact access

Abstract

An information retrieval system with good human-interface methods to give the system ease-of-use having two distinctive features with the first being visual interface and the second being natural language interpretation. The visual interface provides for visual interaction for local search and natural language interpretation provides for linguistic interaction for global search. The visual interface provides versatile views onto the contents of the knowledge base that the system has, controlling mechanisms for browsing through the knowledge base, a capability of showing relevant information for the users, and a mechanism for editing a query expression that describes information to retrieve. By using the visual interface for information retrieval, the users can easily create query expressions, by consulting and reacting with the system. The natural language interpretation makes use of a conceptual network as a knowledge-base that stores important concepts and relationships among these concepts. Based on knowledge and information represented in the conceptual network, the meaning of a noun phrase or a nominal compound which is a string of adjectives and nouns with some prepositions can be inferred. The inferred interpretation of such a noun phrase is paraphrased into an expression that the information retrieval system can handle. Therefore, the user of the system can simply describe the desired information in a language to get the desired information.

Claims

1. A knowledge based document retrieval system, comprising:

user input means for inputting, in response to at least one of a user'"'"'s key-typing and mouse operations, a series of words;

display means for displaying responses from said system and retrieved documents;

user input analysis means for analyzing said series of words inputted by said user through said user input means, and converting said series of words into an internal query condition based on information related to various concepts and permitting said user to edit said internal query condition;

a knowledge base for storing knowledge including said concepts and relations among said concepts;

wherein said stored knowledge is represented by concept nodes and relation links forming a network of concepts, wherein each of said nodes represents a concept, and wherein each of said links represents a relation among said concepts;

information search means for identifying concept nodes that match said internal query condition semantically; and

information retrieval means for retrieving at least one relevant document associated with said identified concept nodes;

wherein said user input analysis means includes;

lexicon storing means having contents which are an edited version of said concept network,

lexical analysis means for identifying concept nodes from said series of words inputted by said user input means by consulting the contents of said lexicon storing means,

syntactic analysis means for identifying a nominal compound in said series of words based on said concept nodes identified by said lexical analysis means, and

nominal compound interpretation means for mapping said identified nominal compound relative to said concepts and relations of said knowledge base, inferring meaning of said identified nominal compound based on said concepts and relations of said knowledge base and generating said internal query condition based on said meaning of said identified nominal compound.

2. A knowledge based file retrieval system according to claim 1, wherein said nominal compound interpretation means generates all possible interpretations, that are represented by interrelationships among said series of nouns, such that interrelationships are relations existing in said concept network, and evaluates likelihood of interpretations depending on the number of instance relations existing in said concept network, wherein instance relations represent concrete facts.

3. A knowledge based file retrieval system according to claim 1

wherein said information storage means stores files representing documents;

wherein said concept nodes includes nodes that represent said documents stored in said information storage means; and

wherein said information retrieval means retrieves documents that are associated with said identified concept nodes.

4. A knowledge-based document retrieval system, comprising:

user input means for inputting, in response to at least one of a user'"'"'s key-typing and mouse operations, a series of words;

user interaction means for creating a query expression and an internal query condition from a dialogue, including said inputted series of words, between said user and said system, wherein said query expression is a displayed version of said internal query condition for said user to permit editing by said user, said query expression and said internal query condition being created based on information related to various concepts;

a knowledge base for storing knowledge including said concepts and relations among said concepts, wherein said stored knowledge is represented by concept nodes and relation links forming a concept network, wherein each of said nodes represents a concept, and wherein each of said links represents a relation among said concepts;

information search means for identifying concept nodes that match said internal query condition semantically;

information retrieval means for retrieving at least one relevant document associated with said identified concept nodes; and

display means for displaying responses from said system and retrieved documents;

wherein said user interaction means includes;

query editing means for adding to said internal query condition a new condition phrase having concepts and relations defined in said concept network, deleting one of existing condition phrases, and changing one of concepts in said condition phrases to a different concept in response to said series of words inputted by said user,

query expression display means for displaying on said display means said query expression corresponding to said internal query condition being created and edited, and

concept tree display means for displaying on said display means part of said concept network in a hierarchical tree, wherein said tree includes one of the concepts appearing in said query expression.

5. A knowledge based document retrieval system according to claim 4, wherein said user interaction means further comprises:

means for searching concepts connected by a generic relationship added to a current concept in the query expression among the concepts connected with said current concept through subsumption relationships, displaying on said display means the concept belonging to the lowest rank in the subsumption relations among these concepts and moving said current concept to the concept being displayed.

6. A knowledge based document retrieval system according to claim 4, wherein said user interaction means further comprises:

means for imposing conditions one after another to a concept in the query expression, a current concept moving freely among the concepts in the query expression.

7. A knowledge based document retrieval system according to claim 4, wherein said user interaction means further comprises:

means for adding a root to a concept, which is to be queried in the query expression and modifying the concept which is to be queried.

8. A knowledge based document retrieval system according to claim 4, wherein said user interaction means further comprises:

means for making the query of the concepts, to which the condition is imposed, in the query expression, possible one after another.

12. A knowledge-based document retrieval system according to claim 4, further comprising:

means for rewriting the display of query expressions by substituting a current concept for a certain concept in said dialogue window representing the network by the current concept.

13. A knowledge-based document retrieval system according to claim 4, wherein said query editing means controls said query expression display means and said concept tree display means, such that, in response to a user selection of a concept in a query expression by means of a mouse operation, said concept tree display means identifies a subset of said concepts corresponding to said selected concept, and displays said subset of concepts in a hierarchical tree.

14. A knowledge based document retrieval system according to claim 13, wherein said query editing means control said query expression display means and said concept tree display means, such that, in response to user selection of a concept in said concept tree display, said query editing means substitutes a corresponding concept in a query expression by said selected concept, and said query expression display means displays the updated version of said query expression.

15. A knowledge based document retrieval system according to claim 4, wherein said query editing means controls said query expression display means to display possible relations that can be attached to a concept in response to a user'"'"'s request to add new condition phrase to a concept in an existing query expression being edited.

9. A document retrieval system using a conceptual network, comprising:

a knowledge base for storing a plurality of words representing concepts and a plurality of predicates representing relations between the plurality of words;

input means for inputting words;

display means for displaying words;

processing means, responsive to inputting of a word representing a concept which serves as a query key from said input means, for retrieving a word representing a concept in association with the inputted word from said knowledge base, and for displaying on said display means at least one word having a relation with said inputted word and at least one predicate representing said relation with said inputted word;

editing means for selecting, in response to said user, a set of a desired word and a predicate from those displayed on said display means and inputting, by said user, a new word subsumed by the selected word to produce a query condition in which said inputted word and the newly inputted word are associated with each other by said selected predicate; and

means for retrieving at least one relevant document related to said query condition.

10. A document retrieving method in an intellectual retrieval system, comprising the steps, performed by said intellectual retrieval system, of:

storing a plurality of words representing concepts and relations between the plurality of words as a knowledge base;

displaying on a screen a query condition defined by selected words and predicates representing relations between the selected words, and displaying a plurality of other words and relations between the words, said plurality of other words having a relation with a certain word in said query condition and being stored in said knowledge base;

permitting a user of said intellectual retrieval system to select one word and one relation from the displayed plurality of other words and relations;

rewriting and displaying said query condition in accordance with the selected word and the relation; and

retrieving at least one relevant document related to said query condition.

11. A method according to claim 10, wherein a certain word in said query condition is designated on the screen, and a plurality of other words having a relation with said designated word and stored in said knowledge base, relations between the plurality of other words are displayed on said screen in response to the designation.

16. A knowledge-based document retrieval system, comprising:

user input means for inputting, in response to at least one of a user'"'"'s key-typing and mouse operations, a series of words;

a knowledge base for storing knowledge including concepts and relations among said concepts, wherein said stored knowledge is represented by concept nodes and relation links forming a concept network, wherein each of said nodes represents a concept, and wherein each of said links represent a relation among said concepts;

information storage means for storing said knowledge base and documents, wherein each document has a corresponding concept node defined in said knowledge base;

information search means for identifying concept nodes that match an internal query condition represented in terms of concepts and relations defined in said knowledge base;

information retrieval means for retrieving documents from said information storage means, wherein said documents are associated with said identified concept nodes;

display means for displaying responses from said system and retrieved documents; and

user interaction means for creating said internal query condition from a dialogue, including said inputted series of words, between said user and said system, wherein said internal query condition is displayed in a query expression to permit said user to edit;

wherein said user interaction means includes;

query editing means for adding to said internal query condition a new condition phrase having concepts and relations defined in said knowledge base, deleting one of existing condition phrases, and changing one of concepts in said condition phrases to a different concept in said knowledge base in response to said series of words inputted by said user,

query expression display means for displaying on said display means said query expression which is a display version of said internal query condition being created and edited, and

concept tree display means for displaying on said display means a subset of concepts defined in said knowledge base in a hierarchical tree, wherein said tree includes one of the concepts appearing in said query internal condition being edited.