Calculating Valence of Expressions within Documents for Searching a Document Index

Abstract

Tools and techniques related to calculating valence of expressions within documents. These tools may provide methods that include receiving input documents for processing, and extracting expressions from the documents for valence analysis, with scope relationships occurring between terms contained in the expressions. The methods may calculate calculating valences of the expressions, based on the scope relationships between terms in the expressions.

What is claimed is: 
     
         1 . A computer-readable storage medium comprising computer-executable instructions stored thereon that, when executed by a computer system, cause the computer system to:
 receive at least one document for processing;   extract at least one expression from the document, the expression containing a scope relationship occurring between at least two terms contained in the expression;   calculate a valence of the expression based on the scope relationship between terms as defined in the expression; and   enter one or more facts in a semantic index representing the valence calculated for the expression, the semantic index comprising an inverted index mapping facts representing valence calculated for expressions in a plurality of documents to the document in which each expression occurs.   
     
     
         2 . The storage medium of  claim 1 , wherein the instructions for calculating a valence include instructions for identifying at least one term within the expression that is within a scope of at least a second term within the expression, for calculating respective valence values associated with at least the first and second terms, and for computing a valence of the expression by analyzing a semantic relationship between the first and second terms. 
     
     
         3 . The storage medium of  claim 1 , wherein the instructions for extracting at least one expression include instructions for extracting an expression that represents at least one direct speech event. 
     
     
         4 . The storage medium of  claim 1 , wherein the instructions for extracting at least one expression include instructions for extracting an expression that represents at least one indirect speech event. 
     
     
         5 . The storage medium of  claim 4 , wherein the indirect speech event represents an embedded speech event, in which a speaker conveys information, and represents a dominating speech event, in which an author reports on the embedded speech event, and expresses sentiment toward the information or toward the speaker. 
     
     
         6 . The storage medium of  claim 1 , wherein the instructions for calculating a valence include instructions for calculating a valence of an expression to account for metaphoric use of at least one term included within the expression. 
     
     
         7 . The storage medium of  claim 1 , wherein the expression represents a first instance of quoted speech, further comprising instructions for extracting at least a second expression from the document, wherein the second expression represents a second instance of quoted speech that includes the first instance of quoted speech, and further comprising instructions for repeating the calculate and enter operations for at least the second expression. 
     
     
         8 . A computer-readable storage medium comprising computer-executable instructions stored thereon that, when executed by a computer system, cause the computer system to:
 calculate a representation of valence of an expression contained within an input document based on a scope relationship between at least two terms contained in the expression, the representation storing data representing an attitude of at least a first speaker toward a reported event;   determine whether the representation expresses a neutral valence or a non-neutral valence; and   upon determining the representation expresses a non-neutral valence, enter a fact for the representation in a semantic index comprising facts representing valence calculated for expressions in a plurality of documents, the fact comprising a role denoting the attitude of the first speaker toward the reported event.   
     
     
         9 . The storage medium of  claim 8 , further comprising instructions for determining whether at least a first term contained in the expression falls within a scope of at least a second term contained in the expression, wherein the instructions for determine scope include instructions for determine scope by using statistical methods or by analyzing surface punctuation occurring with the expression. 
     
     
         10 . The storage medium of  claim 9 , further comprising instructions for determining whether the second term shifts a valence associated with the first term, and further comprising instructions for marking the representation to incorporate the shifted valence of the first term. 
     
     
         11 . The storage medium of  claim 10 , wherein the instructions for determining whether the second term shifts a valence include instructions for calculating a valence shift based on at least one factive, counter-factive, or implicative appearing in the first term or second term. 
     
     
         12 . The storage medium of  claim 10 , wherein the instructions for determining whether the second term shifts a valence include instructions for calculating a valence shift based on a valence mismatch occurs between the first term and the second term. 
     
     
         13 . The storage medium of  claim 9 , further comprising instructions for determining whether the second term establishes who spoke the first term, and further comprising instructions for marking the representation to indicate who spoke the first term. 
     
     
         14 . The storage medium of  claim 9 , further comprising instructions for determining whether the second term establishes a valence for the first term, and further comprising instructions for marking the representation to indicate the valence of the first term. 
     
     
         15 . The storage medium of  claim 14 , wherein the first term is an unknown term, and wherein the first term inherits valence from the second term, by virtue of a scope relationship between the first and second terms. 
     
     
         16 . The storage medium of  claim 8 , wherein the attitude of the first speaker toward the reported event expressed in the expression is ambiguous, and multiple facts for the representation of valence are entered in the semantic index for the expression denoting different attitudes of the first speaker toward the reported event. 
     
     
         17 . A method comprising:
 receiving, at a computer executing a natural language engine, an input document;   calculating, at the computer, a representation of valence of an expression included in the input document based on a scope relationship between at least two terms in the expression, the representation comprising data representing an attitude of at least a first speaker toward a reported event;   determining, at the computer, whether the representation expresses a neutral valence or a non-neutral valence; and   upon determining that the representation expresses a non-neutral valence, entering, by the computer, a fact for the representation in a semantic index comprising facts representing valence calculated for expressions in a plurality of documents, the fact comprising a role denoting the attitude of the first speaker toward the reported event.   
     
     
         18 . The method of  claim 17 , further comprising:
 determining whether a first term contained in the expression falls within a scope of a second term contained in the expression, wherein determining scope comprises determining scope by using a statistical method or by analyzing surface punctuation occurring with the expression.   
     
     
         19 . The method of  claim 18 , further comprising:
 determining whether the second term shifts a valence associated with the first term; and   marking the representation to incorporate the shifted valence of the first term.   
     
     
         20 . The method of  claim 18 , further comprising:
 determining whether the second term establishes who spoke the first term; and   marking the representation to indicate who spoke the first term.