Document analysis apparatus, document analysis method, and computer-readable recording medium

A document analysis method, comprising the steps of:

• (a) accepting an analysis object document to be an analysis object as a first document collection, and furthermore, accepting as an input a feature expression which has appeared during an attention period specified in advance in said first document collection;
• (b) acquiring, as a second document collection, a collection of documents which have been issued, generated or updated during said attention period and in which said acquired feature expression has appeared, from among document collections including said first document collection for every said feature expression;
• (c) specifying, for every said feature expression, a document corresponding to said analysis object document as a first feature expression containing document among documents of said second document collection in which the feature expression has appeared, and furthermore, specifying a context which is common in two or more said first feature expression containing documents as the context of the feature expression, among contexts in which the feature expression has appeared in said first feature expression containing document;
• (d) specifying, for every said feature expression, a document which does not correspond to said analysis object document as a second feature expression containing document, among documents of said second document collection in which the feature expression has appeared, and furthermore, performing comparison between a context in which the feature expression has appeared in said second feature expression containing document and a context specified in said Step (c);
• and
• (e) based on a result of a comparison by said Step (d), giving a feature degree to said feature expression acquired by said Step (a) or correcting a feature degree in the case where the feature degree has been given to said feature expression in advance in said Step (a),
• wherein in said Step (c), after said first feature expression containing document is specified, for every said feature expression, it is determined whether a relation between the number of said first feature expression containing documents and the number of documents in which the feature expression has appeared within said second document collection fulfils a setting condition, and in the case where said setting condition is not fulfilled, specifying of said context is performed, and
• in said Step (d), with respect to each said feature expression for which said context has been specified, comparison between a context in which the feature expression has appeared in said second feature expression containing document and a context specified in said Step (c) is performed.

A non-transient computer-readable recording medium in which a program including instructions is recorded, the instructions making a computer execute the steps of:

• (a) accepting an analysis object document to be an analysis object as a first document collection, and furthermore, accepting as an input a feature expression which has appeared during an attention period specified in advance in said first document collection;
• (b) acquiring, as a second document collection, a collection of documents which have been issued, generated or updated during said attention period and in which said acquired feature expression has appeared, from among document collections including said first document collection for every said feature expression;
• (c) specifying, for every said feature expression, a document corresponding to said analysis object document as a first feature expression containing document among documents of said second document collection in which the feature expression has appeared, and furthermore, specifying a context which is common in two or more said first feature expression containing documents as the context of the feature expression, among contexts in which the feature expression has appeared in said first feature expression containing document;
• (d) specifying, for every said feature expression, a document which does not correspond to said analysis object document as a second feature expression containing document, among documents of said second document collection in which the feature expression has appeared, and furthermore,
• performing comparison between a context in which the feature expression has appeared in said second feature expression containing document and a context specified in said Step (c);
• and
• (e) based on a result of a comparison by said Step (d), giving a feature degree to said feature expression acquired by said Step (a) or correcting a feature degree in the case where the feature degree has been given to said feature expression in advance in said Step (a),
• wherein in said Step (c), after said first feature expression containing document is specified, for every said feature expression, it is determined whether a relation between the number of said first feature expression containing documents and the number of documents in which the feature expressions has appeared within said second document collection fulfils a setting condition, and in the case where said setting condition is not fulfilled, specifying of said context is performed, and
• in said Step (d), with respect to each said feature expression for which said context has been specified, comparison between a context in which the feature expression has appeared in said second feature expression containing document and a context specified in said Step (c) is performed.