Patent Publication Number: US-2019179857-A1

Title: Decision program, decision apparatus and decision method

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is based upon and claims the benefit of priority of the prior Japanese Patent Application No. 2017-236065, filed on Dec. 8, 2017, the entire contents of which are incorporated herein by reference. 
     FIELD 
     The embodiment discussed herein relates to a decision program, a decision apparatus and a decision method. 
     BACKGROUND 
     In recent years, in order to make it possible to smoothly distribute financial information of financial statements and so forth, an extensible business reporting language (XBRL) document (hereinafter referred to also as document) for which XBRL that is a language based on the standard of extensible markup language (XML) is used is generated. 
     This XBRL document is configured from a concept of an instance and a taxonomy, and all financial information to be disclosed is set as instances and taxonomies. In an XBRL document, for example, financial information itself (hereinafter referred to also as item) such as amounts of sales or operating profits is set as an instance, and a definition element such as a display structure or a display method is set as taxonomy (for example, refer to Japanese Laid-open Patent Publication No. 2007-164591, Japanese Laid-open Patent Publication No. 2011-076557 and Japanese Laid-open Patent Publication No. 2005-043932). 
     An instance that constitutes such an XBRL document as described above includes, in addition to various items, a context (hereinafter referred to sometimes simply as attribute) that is information that is referred to from the items and is indicative of company information, a reporting year and so forth. 
     Here, there is the possibility that the information included in each context may be changed at any time in response to a reporting year of financial information or the like. Therefore, for example, in the case where comparison of financial information in different reporting years is performed, a worker specifies an association relationship of a context between different reporting years in advance. For example, in this case, the worker refers to identification information included in the contexts (such identification information is hereinafter referred to also as context identification (ID)) to perform association of the contexts. 
     However, contexts for which such association is to be performed sometimes include a context whose context ID has been changed. Therefore, in this case, it is difficult for the worker to perform association of the contexts by reference to the context IDs. 
     Therefore, the worker performs association of contexts, for example, based on a similarity relationship of the substance between different pieces of information included in the contexts. Consequently, the worker may perform association of contexts even if there exists a context whose context ID has been changed. 
     However, each context for which association is to be performed sometimes includes a plurality of contexts that include information similar in the substance to each other. Therefore, in this case, it is difficult for the worker to perform association of the contexts by referring to a similarity relationship of information included in the contexts. 
     Further, in the case where association of contexts is performed by manual operation, depending upon the substance of the change of the information included in the contexts, the operation burden on the worker required for association of the contexts becomes enormous. 
     Therefore, it is desirable to provide a decision program, a decision apparatus and a decision method capable of specifying an association relationship between attributes included in documents different from each other. 
     SUMMARY 
     According to an aspect of the embodiments, a decision method performed by a computer, the method includes: accepting a first attribute relating to items included in a first document and a second attribute relating to items included in a second document; specifying a first item associated with the accepted first attribute and a second item associated with the accepted second attribute by referring to a storage in which information that associates information that specifies the items included in the first document with an attribute relating to the items included in the first document and information that associates information that specifies the items included in the second document with an attribute relating to the items in the second document are stored; specifying a third item having a specific relationship to the specified first item and a fourth item having a specific relationship to the specified second item by referring to a storage in which information indicative of a relationship between the items included in the first document and information indicative of a relationship between the items included in the second document are stored; and deciding, based on consistency between the specified third item and the specified fourth item, whether or not the first attribute is associated with the second attribute. 
     The object and advantages of the invention will be realized and attained by mean of the elements and combinations particularly pointed out in the claims. 
     It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive of the invention. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  depicts an example of a configuration of an information processing system; 
         FIGS. 2 to 7D  depict particular examples of document information; 
         FIG. 8  depicts a hardware configuration of an information processing apparatus; 
         FIG. 9  depicts functional blocks of an information processing apparatus; 
         FIG. 10  depicts a flow chart illustrating an outline of a decision process according to a first embodiment; 
         FIGS. 11 and 12  depict an outline of the decision process according to the first embodiment; 
         FIGS. 13 to 17  depict flow charts illustrating details of the decision process according to the first embodiment; 
         FIGS. 18A and 18B  depict a particular example of context information; 
         FIGS. 19A and 19B  depict a particular example of item information; 
         FIGS. 20 and 21  depict particular examples of taxonomy information; 
         FIGS. 22 and 23  depict particular examples of match information; 
         FIG. 24  depicts a particular example of map information; 
         FIG. 25  depicts a different particular example of match information; 
         FIG. 26  depicts a particular example of setting information; and 
         FIGS. 27, 28 and 29  depict further different particular examples of match information. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     [Configuration of Information Processing System] 
       FIG. 1  depicts a configuration of an information processing system. The information processing system  10  depicted in  FIG. 1  includes, for example, an information processing apparatus  1  (hereinafter referred to also as decision apparatus  1 ), a storage unit  130  and an operation terminal  3 . The operation terminal  3  depicted in  FIG. 1  is coupled to the information processing apparatus  1  through a network NW such as the Internet. 
     The operation terminal  3  is a terminal that is used, for example, by a worker. For example, the worker inputs an XBRL document  131  (hereinafter referred to also as document information  131 ) constituted from instances and taxonomies through the operation terminal  3 . 
     The information processing apparatus  1  stores the document information  131  inputted from the operation terminal  3  into the storage unit  130 . For example, the information processing apparatus  1  stores the document information  131  of each reporting year in a sorted state into the storage unit  130 . 
     Then, the information processing apparatus  1  performs, for example, a process of referring to the document information  131  stored in the storage unit  130  and deciding whether or not contexts included in instances constituting the document information  131  of different reporting years are associated with each other (such process is hereinafter referred to also as decision process). In the following, a particular example of the document information  131  is described. 
     [Particular Example of Document Information] 
       FIGS. 2 to 7D  are views illustrating particular examples of document information. The document information here may be the document information  131  depicted in  FIG. 1 . It is to be noted that the following description is given assuming that first document information  131   a  and second document information  131   b  (that is document information  131  corresponding to a reporting year newer than that of the first document information  131   a ) are stored in the storage unit  130 . Further, the following description is given assuming that a taxonomy constituting the first document information  131   a  and the second document information  131   b  includes a schema, a presentation linkbase, a definition linkbase and a label linkbase. 
     [Particular Example of Document Structure in Document Information] 
     First, particular examples of a document structure in the document information  131  are described.  FIG. 2  is a view illustrating a particular example of a document structure in the first document information  131   a , and  FIG. 3  is a view illustrating a particular example of a document structure in the second document information  131   b.    
     The document structure of the first document information  131   a  depicted in  FIG. 2  indicates that a file corresponding to an instance (file whose file name is “instance2016.xbrl”) is a file that is referred to from a file corresponding to a schema (a file whose file name is “schema2016.xsd”). 
     Further, the document structure of the first document information  131   a  depicted in  FIG. 2  indicates that a file corresponding to the schema is a file that is referred to from a file corresponding to the presentation linkbase (file whose file name is “presentation2016.xml”), a file corresponding to the definition linkbase (file whose file name is “definition2016.xml”) and a file corresponding to the label linkbase (file whose file name is “labe12016.xml”). 
     Meanwhile, the document structure of the second document information  131   b  depicted in  FIG. 3  indicates that a file corresponding to the instance (file whose file name is “instance2017.xbrl”) is a file that is referred to from a file corresponding to the schema (file whose file name is “schema2017.xsd”). 
     Further, the document structure of the second document information  131   b  depicted in  FIG. 3  indicates that a file corresponding to the schema is a file that is referred to from a file corresponding to the presentation linkbase (file whose file name is “presentation2017.xml”), a file corresponding to the definition linkbase (file whose file name is “definition2017.xml”) and a file corresponding to the label linkbase (file whose file name is “labe12017.xml”). 
     [Particular Example of Instance Constituting Document Information] 
     Now, a particular example of an instance configuring the document information  131  is described.  FIG. 4  is a view depicting a particular example of a file corresponding to an instance that constitutes the first document information  131   a  and  FIG. 5  is a view depicting a particular example of a file corresponding to an instance that constitutes the second document information  131   b.    
     The instance depicted in  FIG. 4  includes information indicating that the item value of “SalesDom” that is an item for referring to a context whose context ID is “C1” is “100,” information indicating that the item value of “SalesDom” that is an item for referring to a context whose context ID is “C4” is “50,” and information indicating that the item value of “SalesFor” that is an item for referring to a context whose context ID is “C1” is “200.” 
     Further, the instance depicted in  FIG. 4  includes, for example, information that indicates that a context whose context ID is “C1” includes information indicating that “date” is “2016/6/15˜” and information indicating that “product” is “Software.” Description of the other information included in the instance depicted in  FIG. 4  is omitted. 
     Meanwhile, the instance depicted in  FIG. 5  includes information indicating that the item value of “Sales” that is an item for referring to a context whose context ID is “C2” is “100,” information indicating that the item value of “Sales” that is an item for referring to a context whose context ID is “C5” is “50,” and information indicating that the item value of “Cost” that is an item for referring to a context whose context ID is “C3” is “10.” 
     Further, the instance depicted in  FIG. 5  includes, for example, information indicating that a context whose context ID is “C2” includes information indicating that “date” is “2017/6/29˜,” information indicating that “product” is “Software” and information indicating that “district” is “Domestic.” Description of the other information included in the instance depicted in  FIG. 5  is omitted. 
     [Particular Example of Taxonomy Constituting Document Information] 
     Now, a particular example of a taxonomy constituting the document information  131  is described.  FIGS. 6A to 6D  are views illustrating particular examples of a file corresponding to a taxonomy constituting the first document information  131   a .  FIG. 6A  depicts a particular example of a file corresponding to the schema;  FIG. 6B  depicts a particular example of a file corresponding to the presentation linkbase;  FIG. 6C  depicts a particular example of a file corresponding to the definition linkbase; and  FIG. 6D  depicts a particular example of a file corresponding to the label linkbase. Meanwhile,  FIGS. 7A to 7D  are views illustrating particular examples of a taxonomy constituting the second document information  131   b .  FIG. 7A  depicts a particular example of a file corresponding to the schema;  FIG. 7B  depicts a particular example of a file corresponding to the presentation linkbase;  FIG. 7C  depicts a particular example of a file corresponding to the definition linkbase; and  FIG. 7D  depicts a particular example of a file corresponding to the label linkbase. 
     The schema depicted in  FIG. 6A  includes information that defines, for example, “Sales,” “SalesDom,” “SalesFor” and “Cost” as items of the monetary type, and information that defines “Software,” “Hardware,” “Type1” and “Type2” as items of the string type. Meanwhile, the presentation linkbase depicted in  FIG. 6B  includes information indicating that, for example, “Sales,” “SalesDom” and “SalesFor” constitute a hierarchical structure and “Sales” is a parent item (item included in an upper hierarchy) of “SalesDom” and “SalesFor.” Further, the presentation linkbase depicted in  FIG. 6B  includes information indicating that, for example, a hierarchical structure including “Cost” is not formed. 
     Further, the definition linkbase depicted in  FIG. 6C  includes information indicating that, for example, “AllProducts,” “Software” and “Hardware” constitute a hierarchical structure and “AllProducts” is a parent item of “Software” and “Hardware.” Further, the definition linkbase depicted in FIG.  6 C includes information indicating that, for example, “AllTypes,” “Type1” and “Type2” constitute a hierarchical structure and “AllTypes” is a parent item of “Type1” and “Type2.” Furthermore, the label linkbase depicted in  FIG. 6D  includes information indicating that, for example, “Sale,” “SalesDom,” “SalesFor,” “Cost” and “Software” are “amount of sales,” “amount of domestic sales,” “amount of overseas sales,” “sales cost” and “software,” respectively. 
     Further, the schema depicted in  FIG. 7A  includes, for example, information that defines “Sales” and “Cost” as items of the monetary type and information that defines “Software,” “Hardware,” “Domestic,” “MiddlewareDiv,” “Type2” and “Type3” as items of the string type. Further, the presentation linkbase depicted in  FIG. 7B  includes information indicating that, for example, a hierarchical structure including “Sales” is not formed. Furthermore, the presentation linkbase depicted in  FIG. 7B  includes information indicating that, for example, a hierarchical structure including “Cost” is not formed. 
     Meanwhile, the definition linkbase depicted in  FIG. 7C  includes information indicating that, for example, “AllProducts,” “Software” and “Hardware” constitute a hierarchical structure and “AllProducts” is a parent item of “Software” and “Hardware.” Further, the definition linkbase depicted in  FIG. 7C  includes information indicating that, for example, “AllRegions” and “Domestic” constitute a hierarchical structure and “AllRegions” is a parent item of “Domestic.” Further, the definition linkbase depicted in  FIG. 7C  includes information indicating that, for example, “AllDepts” and “MiddlewareDiv” constitute a hierarchical structure and “AllDepts” is a parent item of “MiddlewareDiv.” Furthermore, the definition linkbase depicted in  FIG. 7C  includes information indicating that, for example, “AllTypes,” “Type2” and “Type3” constitute a hierarchical structure and “AllTypes” is a parent item of “Type2” and “Type3.” Meanwhile, the label linkbase depicted in  FIG. 7D  includes information indicating that, for example, the labels corresponding to “Sales,” “Cost” and “Software” are “amount of sales,” “sales cost” and “software,” respectively. 
     Here, there is the possibility that the information included in each context described with reference to  FIGS. 4 and 5  may be changed at any time in response to a reporting year of financial information or the like. Therefore, for example, in the case where comparison of financial information in different reporting years is performed, a worker specifies an association relationship of contexts corresponding to different reporting years in advance. For example, in this case, the worker refers to context IDs included in the contexts to perform association of the contexts. 
     However, there is the possibility that contexts for which such association is to be performed may include a context whose context ID has been changed. Therefore, in this case, it is difficult for the worker to perform association of the contexts by referring to the context IDs. 
     Therefore, the worker performs association of contexts, for example, based on a similarity relationship between different pieces of information included in the contexts. Consequently, the worker may perform association of contexts even if there exists a context whose context ID has been changed. 
     However, each context for which association is to be performed sometimes includes a plurality of contexts that include information similar in the substance to each other. Therefore, in this case, it is difficult for the worker to perform association of the contexts by referring to a similarity relationship of information included in the contexts. 
     Further, in the case where association of contexts is performed by manual operation, depending upon the substance of the change of the information included in the contexts, the operation burden on the worker required for association of the contexts becomes enormous. 
     Therefore, the information processing apparatus  1  in the present embodiment accepts contexts relating to items included in first document information  131   a  (hereinafter referred to also as first document  131   a ) (such context is hereinafter referred to also as comparison source context or first attribute) and contexts relating to items included in second document information  131   b  (hereinafter referred to also as second document  131   b ) (such context is hereinafter referred to also as comparison destination context or second attribute). For example, the information processing apparatus  1  acquires contents included in the first document information  131   a  and the second document information  131   b  stored in the storage unit  130 . 
     Then, the information processing apparatus  1  refers to the storage unit  130 , which stores information that associates information that specifies items included in the first document information  131   a  with contexts relating to the items and information that associates information that specifies items included in the second document information  131   b  with contexts relating to the items, and specifies an item associated with the comparison source context (such an item is hereinafter referred to also as first item) and an item associated with the comparison destination context (such an item is hereinafter referred to also as second item). 
     Then, the information processing apparatus  1  refers to the storage unit  130 , which stores information indicative of a relationship between the items included in the first document information  131   a  and information indicative of a relationship between the items included in the second document information  131   b , and specifies an item having a specific relationship to the first item (such an item is hereinafter referred to also as third item) and another item having a specific relationship to the second item (such an item is hereinafter referred to also as fourth item). 
     Further, the information processing apparatus  1  decides based on consistency between the third item and the fourth item whether or not the comparison destination context is associated with the comparison source context. 
     For example, the information processing apparatus  1  generates information indicative of items that refer to the contexts and information indicative of a relationship between the items in advance from information included in the first document information  131   a  and the second document information  131   b  stored in the storage unit  130 . Then, the information processing apparatus  1  estimates an association relationship between the comparison source context (context included in the first document information  131   a ) and the comparison destination context (context included in the second document information  131   b ) based on the information indicative of the items that refer to the contexts and the information indicative of a relationship between the items. 
     Consequently, even in the case where the context ID of a context is changed or a plurality of contexts similar to a context exist, the information processing apparatus  1  may perform specification of a context to be associated with each context. 
     [Hardware Configuration of Information Processing Apparatus] 
     Now, a hardware configuration of an information processing apparatus is described.  FIG. 8  is a view depicting a hardware configuration of an information processing apparatus. The information processing apparatus here may be the information processing apparatus) depicted in  FIG. 1 . 
     As depicted in  FIG. 8 , the information processing apparatus  1  includes a central processing unit (CPU)  101  that is a processor, a memory  102 , an external interface (hereinafter referred to also as input/output (I/O) unit)  103 , a storage medium  104 , and a display apparatus  105  that displays various kinds of information. The components mentioned of the information processing apparatus  1  are coupled to each other by a bus  106 . 
     The storage medium  104  stores a program  110  for performing a decision process, for example, in a program storage region (not depicted) in the storage medium  104 . The storage medium  104  may be, for example, a hard disk drive (HDD). 
     Further, the storage medium  104  includes, for example, a storage unit  130  (also referred to as information storage region  130 ) that stores information to be used when a decision process is performed. 
     The CPU  101  executes the program  110  loaded into the memory  102  from the storage medium  104  and performs a decision process. 
     The I/O unit  103  performs communication, for example, with the operation terminal  3 . 
     [Function of Information Processing Apparatus] 
     Now, functions of an information processing apparatus are described.  FIG. 9  is a block diagram of functions of an information processing apparatus. The information processing apparatus here may be the information processing apparatus) depicted in  FIG. 1 . 
     The information processing apparatus  1  implements, by organic cooperation of hardware such as the CPU  101  and memory  102  with the program  110 , various functions including an information acceptance unit  111 , an association decision unit  112 , a first item specification unit  113 , a second item specification unit  114  and a result outputting unit  115  as depicted in  FIG. 9 . 
     Further, in the information storage region  130  described with reference to  FIG. 8  and so forth, for example, document information  131 , setting information  132 , context information  133 , item information  134 , taxonomy information  135 , match information  136  and map information  137  are stored. 
     The information acceptance unit  111  accepts, for example, first document information  131   a  and second document information  131   b  inputted from the operation terminal  3 . Then, the information acceptance unit  111  stores the accepted first document information  131   a  and second document information  131   b  into the information storage region  130 . 
     Further, the information acceptance unit  111  generates, from a comparison source context included in an instance constituting the first document information  131   a  and a comparison destination text included in an instance constituting the second document information  131   b , context information  133  indicative of information included in each context. Further, the information acceptance unit  111  generates, from items included in instances constituting the first document information  131   a  and items included in instances constituting the second document information  131   b , item information  134  that is information that associates information that specifies the items and contexts relating to the items with each other. Furthermore, the information acceptance unit  111  generates, from taxonomies constituting the first document information  131   a  and taxonomies constituting the second document information  131   b , taxonomy information  135  indicative of information included in each taxonomy (for example, information including a relationship between the items). Then, the information acceptance unit  111  stores the generated context information  133 , item information  134  and taxonomy information  135  into the information storage region  130 . A particular example of the context information  133 , item information  134  and taxonomy information  135  is hereinafter described. 
     The association decision unit  112  refers, for example, to the context information  133  stored in the information storage region  130  and decides whether or not the information included in the comparison source context and the information included in the comparison destination context match with each other. 
     The first item specification unit  113  refers to the item information  134  stored in the information storage region  130  and specifies a first item associated with the comparison source context and a second item associated with the comparison destination context. For example, the first item specification unit  113  may specify the first item and the second item in the case where the association decision unit  112  decides that the ratio of the information included in the comparison destination context, which matches with the information included in the comparison source context, is equal to or higher than a threshold value included in the setting information  132  set in advance in the information storage region  130 . A particular example of the setting information  132  is hereinafter described. 
     The second item specification unit  114  refers to the taxonomy information  135  stored in the information storage region  130  and specifies a third item having a specific relationship to the first item specified by the first item specification unit  113  and a fourth item having a specific relationship to the second item specified by the first item specification unit  113 . For example, the second item specification unit  114  performs specification of a third item that is a parent item of the first item and a fourth item that is a parent item of the second item. 
     Then, the association decision unit  112  decides based on the consistency between the third item and the fourth item specified by the second item specification unit  114  whether or not the comparison destination context is associated with the comparison source context. 
     Thereafter, the result outputting unit  115  outputs, for example, a result of the decision regarding whether or not the comparison destination context is associated with the comparison source context (decision result by the association decision unit  112 ) to the operation terminal  3 . It is to be noted that the match information  136  and the map information  137  are hereinafter described. 
     [Outline of First Embodiment] 
     Now, an outline of a first embodiment is described.  FIG. 10  is a flow chart illustrating an outline of a decision process according to the first embodiment. Further,  FIGS. 11 and 12  are views illustrating an outline of the decision process according to the first embodiment. An outline of the decision process depicted in  FIG. 10  is described with reference to  FIGS. 11 and 12 . 
     As depicted in  FIG. 10 , the information processing apparatus  1  waits till a decision timing for an association relationship of contexts (NO at S 1 ). The decision timing of an association relationship of contexts may be, for example, a timing at which the worker performs inputting through the operation terminal  3  to perform decision of an association relationship of contexts. 
     When a decision timing for an association relationship of contexts comes (YES at S 1 ), the information processing apparatus  1  accepts a first attribute relating to items included in the first document information  131   a  and a second attribute relating to items included in the second document information  131   b  (S 2 ). 
     Then, as depicted in  FIG. 11 , the information processing apparatus  1  refers to the storage unit  130 , which stores information that associates information that specifies items included in the first document information  131   a  with attributes relating to the items and information that associates information that specifies items included in the second document information  131   b  with attributes relating to the items, and specifies a first item associated with the first attribute accepted by the process at S 2  and a second item associated with the second attribute accepted by the process at S 2  (S 3 ). 
     Further, as depicted in  FIG. 12 , the information processing apparatus  1  refers to the storage unit  130 , which stores information indicative of a relationship between the items included in the first document information  131   a  and information indicative of a relationship between the items included in the second document information  131   b , and specifies a third item having a specific relationship with the first item specified by the process at S 3  and a fourth item having a specific relationship with the second item specified by the process at S 3  (S 4 ). 
     Thereafter, the information processing apparatus  1  decides, based on the consistency between the third item specified by the process at S 4  and the fourth item specified by the process at S 4 , whether or not the first attribute corresponds to the second attribute (S 5 ). 
     For example, the information processing apparatus  1  generates, from information included in the first document information  131   a  and the second document information  131   b  stored in the storage unit  130 , information indicative of items that refer to the contexts and information indicative of a relationship between the items in advance. Then, the information processing apparatus  1  estimates, based on the information indicative of the items that refer to the contexts and the information indicative of a relationship between the items, an association relationship between the comparison source context (context included in the first document information  131   a ) and the comparison destination context (context included in the second document information  131   b ). 
     Consequently, even in the case where the context ID of a context is changed or a plurality of contexts similar to a context exist, the information processing apparatus  1  may perform specification of a context to be associated with each context. 
     [Details of First Embodiment] 
     Now, details of the first embodiment are described.  FIGS. 13 to 17  are flow charts illustrating details of the decision process in the first embodiment. Further,  FIGS. 18A to 29  are views illustrating details of the decision process in the first embodiment. Details of the decision process of  FIGS. 13 to 17  are described with reference to  FIGS. 18A to 29 . 
     As depicted in  FIG. 13 , the information acceptance unit  111  of the information processing apparatus  1  waits till a decision timing for an association relationship of contexts (NO at S 11 ). 
     In the case where a decision timing for an association relationship of contexts comes (YES at S 11 ), the information acceptance unit  111  acquires, for example, the first document information  131   a  and the second document information  131   b  stored in the information storage region  130  (S 12 ). 
     Then, the information acceptance unit  111  generates context information  133 , item information  134  and taxonomy information  135  from the first document information  131   a  and the second document information  131   b  acquired by the process at S 12  (S 13 ). Then, the information acceptance unit  111  stores the generated context information  133 , item information  134  and taxonomy information  135  into the information storage region  130 . In the following, a particular example of the context information  133 , item information  134  and taxonomy information  135  is described. 
     [Particular Example of Context Information] 
     First, a particular example of the context information  133  is described.  FIGS. 18A and 18B  are views illustrating particular examples of the context information  133 .  FIG. 18A  depicts a particular example of the first context information  133   a  generated from the first document information  131   a , and  FIG. 18B  depicts a particular example of the second context information  133   b  generated from the second document information  131   b.    
     The context information  133  depicted in  FIGS. 18A and 18B  includes “item number” for identifying each piece of information included in the context information  133 , “context ID” to which a context ID is set, and “substance” to which information included in a context corresponding to the context ID is set. 
     For example, in the instance described with reference to  FIG. 4 , information included in a context whose context ID is “C1” includes “date: 2016/6/15˜” and “product: Software.” Therefore, the information acceptance unit  111  sets “C1” as “context ID” of information whose “item number” is “1” and sets “date: 2016/6/15˜” and “product: Software” as “substance” as depicted in  FIG. 18A . Description of the other information included in  FIG. 18A  is omitted. 
     Meanwhile, in the instance described with reference to  FIG. 5 , information included in a context whose context ID is “C2” includes “date: 2017/6/29˜,” “product: Software” and “district: Domestic.” Therefore, the information acceptance unit  111  sets “C2” as “context ID” of information whose “item number” is “1,” sets “date: 2017/6/29˜,” “product: Software” and “district: Domestic” as “substance” as depicted in  FIG. 18B . Description of the other information included in  FIG. 18B  is omitted. 
     [Particular Example of Item Information] 
     Now, particular examples of the item information  134  are described.  FIGS. 19A and 19B  are views illustrating a particular example of the item information  134 .  FIG. 19A  is a view illustrating a particular example of the first item information  134   a  generated from the first document information  131   a , and  FIG. 19B  is a view illustrating a particular example of the second item information  134   b  generated from the second document information  131   b.    
     The item information  134  depicted in  FIGS. 19A and 19B  includes “item number” for identifying each piece of information included in the item information  134 , “item name” to which an item name is set, “context ID” to which a context ID associated with a context referred to by an item having an item name set in “item name” is set, and “item value” to which an item value corresponding to an item having an item name set in “item name” is set. 
     For example, the instance described with reference to  FIG. 4  includes information indicating that the item value of “SalesDom” that is an item that refers to a context whose context ID is “C1” is “100.” Therefore, the information acceptance unit  111  sets “SalesDom” as “item name” of information whose “item number” is “1,” sets “C1” as “context ID” and sets “100” as “item value” as depicted in  FIG. 19A . Description of the other information included in  FIG. 19A  is omitted. 
     Meanwhile, the instance described with reference to  FIG. 5  includes information indicating that the item value of “Sales” that is an item that refers to a context whose context ID is “C2” is “100.” Therefore, the information acceptance unit  111  sets “Sales” as “item name” of information whose “item number” is “1,” sets “C2” as “context ID” and sets “100” as “item value” as depicted in  FIG. 19B . Description of the other information included in  FIG. 19B  is omitted. 
     [Particular Example of Taxonomy Information] 
     Now, a particular example of the taxonomy information  135  is described.  FIGS. 20 and 21  are views illustrating particular examples of the taxonomy information  135 .  FIG. 20  depicts a particular example of the first taxonomy information  135   a  generated from the first document information  131   a , and  FIG. 21  depicts a particular example of the second taxonomy information  135   b  generated from the second document information  131   b.    
     The taxonomy information  135  depicted in  FIGS. 20 and 21  includes “item number” for identifying each piece of information included in the taxonomy information  135  and “item name” to which an item name is set. Further, the taxonomy information  135  depicted in  FIGS. 20 and 21  further includes “presentation link parent” to which an item name corresponding to a parent item of an item having an item name set in “item name” from within information included in the presentation linkbase is set and “definition link parent” to which an item name corresponding to a parent item of an item having an item name set in “item name” from within information included in the definition linkbase is set. Further, the taxonomy information  135  depicted in  FIGS. 20 and 21  includes “label” to which a label of an item having an item name set in “item name” from within information included in the label linkbase is set and “definition substance” to which the definition substance of an item having an item name set in “item name” from within information included in the schema is set. It is to be noted that, in the case where a taxonomy constituting the document information  131  includes a different linkbase (for example, a calculation linkbase, a reference linkbase or the like), the information acceptance unit  111  may include information included in the different linkbase into the taxonomy information  135 . 
     For example, the schema described with reference to  FIG. 6A  includes information that defines “Sales” as an item of the monetary type, and the label linkbase described with reference to  FIG. 6D  includes information indicating that the label corresponding to “Sales” is “amount of sales.” Therefore, the information acceptance unit  111  sets “Sales” as “item name” of the information whose “item number” is “1,” sets “amount of sales” as “label” and sets “monetary type” as “definition substance” as depicted in  FIG. 20 . Then, the information acceptance unit  111  sets “-” indicating that information is not set as “presentation link parent” and “definition link parent” of the information whose “item number” is “1” as depicted in  FIG. 20 . 
     Meanwhile, the schema described with reference to  FIG. 6A  includes information that defines “SalesDom” as an item of the monetary type, and the presentation linkbase described with reference to  FIG. 6B  includes information indicating that “Sales” is a parent item of “SalesDom.” Further, the label linkbase described with reference to  FIG. 6D  includes information indicating that the label corresponding to “SalesDom” is “amount of domestic sales.” Therefore, the information acceptance unit  111  sets “SalesDom” as “item name” of the information whose “item number” is “2,” sets “Sales” as “presentation link parent,” sets “-” as “definition link parent,” sets “amount of domestic sales” as “label,” and sets “monetary type” as “definition substance” as depicted in  FIG. 20 . 
     Further, the schema described with reference to  FIG. 6A  includes information that defines “Software” as an item of the monetary type, and the definition linkbase described with reference to  FIG. 6C  includes information indicating that “AllProducts” is a parent item of “Software.” Further, the label linkbase described with reference to  FIG. 6D  includes information indicating that the label corresponding to “SalesDom” is “amount of overseas sales.” Therefore, the information acceptance unit  111  sets “Software” as “item name” of the information whose “item number” is “5,” sets “-” as “presentation link parent,” sets “AllProducts” as “definition link parent,” sets “software” as “label,” and sets “string type” as “definition substance” as depicted in  FIG. 20 . Description of the other information included in  FIG. 20  is omitted. Meanwhile, the information included in  FIG. 21  is same as that described in connection with  FIG. 20 , and therefore, overlapping description of the information is omitted. 
     Referring back to  FIG. 13 , the association decision unit  112  of the information processing apparatus  1  generates match information  136  indicative of a result of comparison between the first context information  133   a  of the first document information  131   a  and the second context information  133   b  of the second document information  131   b  generated by the process at S 13  (S 14 ). Then, the association decision unit  112  stores the generated match information  136  into the information storage region  130 . In the following, a particular example of the match information  136  is described. 
     [Particular Example of Match Information] 
       FIGS. 22, 23, 25, 27, 28 and 29  are views illustrating particular examples of the match information  136 . 
     The match information  136  depicted in  FIG. 22  and so forth includes “item number” for identifying each piece of information included in the match information  136 , “comparison source context ID” to which a context ID of the first context information  133   a  is set, and “comparison destination context ID” to which a context ID of the second context information  133   b  is set. The match information  136  depicted in  FIG. 22  and so forth further includes “comparison result” to which a result of comparison between the context ID set in “comparison source context ID” and the context ID set in the “comparison destination context ID.” 
     For example, the contexts included in the instance described with reference to  FIG. 4  include contexts whose context ID is “C1,” “C4,” “C5,” “C6” and “C7.” Further, the contexts included in the instance described with reference to  FIG. 5  include contexts whose context ID is “C2,” “C3,” “C5,” “C8” and “C9.” Therefore, the association decision unit  112  specifies, for example, only the context whose context ID is “C5” as a context included in both the instance described with reverence to  FIG. 4  and the instance described with reference to  FIG. 5 . 
     Accordingly, as depicted in  FIG. 22 , the association decision unit  112  sets “C5” as “comparison source context ID” and “comparison destination context ID” of the information whose item number is “5.” Then, the association decision unit  112  sets “associated (context ID)” indicating that the context IDs set in “comparison source context ID” and “comparison destination context ID” are associated with each other as “comparison result” of the information whose “item number” is “5” as depicted in  FIG. 22 . 
     On the other hand, as depicted in  FIG. 22 , the association decision unit  112  sets, for example, “C1” that is a context ID other than “C5” as “comparison source context ID” of the information whose “item number” is “1,” sets “-” as “comparison destination context ID,” and sets “not associated” as “comparison result.” Further, as depicted in  FIG. 22 , the association decision unit  112  sets, for example, “-” as “comparison source context ID” of the information whose “item number” is “2,” sets “C2” that is a context ID other than “C5” as “comparison destination context ID,” and sets “not associated” as “comparison result.” Description of the other information included in  FIG. 22  is omitted. 
     Referring back to  FIG. 14 , the association decision unit  112  decides whether or not a manual input of a comparison result (comparison result between the first context information  133   a  and the second context information  133   b ) is accepted by the information acceptance unit  111  (S 21 ). For example, the association decision unit  112  decides whether or not the worker performs inputting of a comparison result by a manual operation through the operation terminal  3  before a given period of time elapses after generation of the match information  136  is performed by the process at S 14 . 
     As a result, in the case where it is decided that a manual input of a comparison result is accepted (YES at S 21 ), the association decision unit  112  reflects the comparison result accepted by the process at S 21  on the match information stored in the information storage region  130  (S 22 ). 
     For example, the information acceptance unit  111  accepts a comparison result including information that indicates that the context whose context ID is “C6” and the context whose context ID is “C8” are associated with each other. In this case, the association decision unit  112  sets “associated (manual)” indicating the decision that the contexts are associated with each other is made by a manual operation of the worker to “comparison result” of the information to whose “comparison source context ID” and “comparison destination context ID” “C6” and “C8” are set, respectively, (namely, the information whose “item number” is “6”) as depicted in  FIG. 23 . 
     Consequently, it becomes possible for the association decision unit  112  to efficiently perform comparison between the first context information  133   a  and the second context information  133   b.    
     Thereafter, the association decision unit  112  generates map information  137  from information included in the comparison result accepted by the process at S 21  (S 23 ). The map information  137  is information indicative of, from within the information included in the first context information  133   a  and the second context information  133   b , information decided to be same information by the comparison by a manual operation of the worker. Then, the association decision unit  112  stores the generated map information  137  into the information storage region  130 . 
     Consequently, it becomes possible for the association decision unit  112  to efficiently perform comparison between the first context information  133   a  and the second context information  133   b  by referring to the map information  137  stored in the information storage region  130 . 
     On the other hand, in the case where it is decided that a manual input of a comparison result is not accepted (NO at S 21 ), the association decision unit  112  does not perform the processes at S 22  and S 23 . In the following, a particular example of the map information  137  is described. 
     [Particular Example of Map Information] 
       FIG. 24  is a view illustrating a particular example of the map information  137 . 
     The map information  137  depicted in  FIG. 24  includes “item number” for identifying each piece of information included in the map information  137 , “comparison source information” to which information included in the first context information  133   a  is set, and “comparison destination information” to which information included in the second context information  133   b  is set. 
     For example, as depicted in  FIG. 24 , the association decision unit  112  sets “Type1” as “comparison source information” of the information whose “item number” is “1” and sets “Type3” as “comparison destination information.” Further, as depicted in  FIG. 24 , the association decision unit  112  sets, for example, “2016/6/15” as “comparison source information” of the information whose “item number” is “2” and sets “2017/6/29” as “comparison destination information.” 
     Referring back to  FIG. 14 , the association decision unit  112  refers to the match information  136  stored in the information storage region  130  and decides whether or not a combination of information for which association is not performed as yet and which is not acquired by a process at S 31  hereinafter described exists in the first context information  133   a  included in the first document information  131   a  and the second context information  133   b  included in the second document information  131   b  (S 24 ). 
     For example, the association decision unit  112  refers to the match information  136  described with reference to  FIG. 23  and decides whether or not a combination, which is not acquired as yet by the process at S 31 , of information set to “comparison source context” and information set to “comparison destination context” of information to whose “comparison result” “not associated” is set. 
     As a result, in the case where it is decided that such combination of information does not exist (NO at S 25 ), the result outputting unit  115  of the information processing apparatus  1  outputs, for example, the match information  136  stored in the information storage region  130  to the operation terminal  3  (S 26 ). Thereafter, the information processing apparatus  1  ends the decision process. 
     For example, in this case, the result outputting unit  115  decides that the comparison between the first context information  133   a  and the second context information  133   b  is completed and performs outputting of the match information  136  that is a result of the comparison between the first context information  133   a  and the second context information  133   b.    
     On the other hand, in the case where it is decided that such combination of information as described above exists (YES at S 25 ), the association decision unit  112  acquires one combination of pieces of information decided to exist by the process at S 24  from the first context information  133   a  included in the first document information  131   a  and the second context information  133   b  included in the second document information  131   b  as depicted in  FIG. 15  (S 31 ). 
     For example, in the match information  136  described with reference to  FIG. 23 , the information set to “comparison source context ID” of the information to whose “comparison result” “not associated” is set is “C1,” “C4” and “C7.” Further, in the match information  136  described with reference to  FIG. 23 , the information set to “comparison destination context ID” of the information to whose “comparison result” “not associated” is set is “C2,” “C3” and “C9.” Therefore, in the case where the process at S 31  is performed for the first time, the association decision unit  112  acquires a combination of one of “C1,” “C4” and “C7” and one of “C2,” “C3” and “C9.” 
     Then, the association decision unit  112  refers to the map information  137  stored in the information storage region  130  and compares the substances of pieces of information included in the combination acquired by the process at S 31  (S 32 ). 
     For example, the association decision unit  112  performs processing assuming that the information set in “comparison source information” and the information set in the “comparison destination information” in the item numbers of the map information  137  described with reference to  FIG. 24  are pieces of information that match with each other. 
     As a result, in the case where it is decided that the substances of the pieces of information included in the combination acquired by the process at S 31  match with each other (YES at S 33 ), the association decision unit  112  reflects the information that the pieces of information acquired by the process at S 31  are associated with each other on the match information  136  stored in the information storage region  130  (S 34 ). Then, the association decision unit  112  performs the processes at the steps beginning with S 24  again. 
     For example, in the map information  137  described with reference to  FIG. 24 , to the information whose “item number” is “2,” “2016/6/15” is set as “comparison source information,” and “2017/6/29” is set as “comparison destination information.” Further, to the information to whose “context ID” “C7” is set in the first context information  133   a  described with reference to  FIG. 18A , “date: 2016/6/15˜” and “type: Type2” are set, and to the information to whose “context ID” “C9” is set in the second context information  133   b  described with reference to  FIG. 18B , “date: 2016/6/29˜” and “type: Type2” are set. Therefore, in this case, the association decision unit  112  may decide that the context whose context ID is “C7” and the context whose context ID is “C9” are associated with each other. 
     Accordingly, in the case where the combination of the pieces of information whose context ID is “C7” and “C9” is acquired by the process at S 31 , the association decision unit  112  sets “associated (decision process)” indicating that it is decided by the decision process that the contexts are associated with each other to “comparison result” of the information to whose “comparison source context ID” and “comparison destination context ID” “C7” and “C9” are set, respectively, (information whose “item number” is “7”) as depicted in  FIG. 25 . 
     On the other hand, in the case where it is decided that the substances of the pieces of information included in the combination acquired by the process at S 31  do not match with each other (NO at S 33 ), the association decision unit  112  specifies the ratio of the matching information in the information acquired by the process at S 31  as depicted in  FIG. 16  (S 41 ). 
     For example, the association decision unit  112  specifies the ratio of information that matches with the information included in the first context information  133   a  acquired by the process at S 31  from within the information included in the second context information  133   b  acquired by the process at S 31 . 
     For example, in the first context information  133   a  described with reference to  FIG. 18A , to “substance” of the information to whose “context ID” “C1” is set, “date: 2016/6/15˜” and “product: Software” are set. Meanwhile, in the second context information  133   b  described with reference to  FIG. 18B , to “substance” of the information to whose “context ID” “C2” is set, “date: 2017/6/29˜,” “product: Software” and “district: Domestic” are set. Furthermore, in the map information  137  described with reference to  FIG. 24 , to “comparison destination information” of the information to whose “comparison source information” “2016/6/15” is set (information whose “item number” is “2”), “2017/6/29” is set. 
     Therefore, the association decision unit  112  decides that “date: 2017/6/29˜” and “product: Software” in the information set in “substance” of the information to whose “context ID” “C2” is set match with the information set in “substance” of the information to whose “context ID” “C1” is set. Accordingly, in this case, the association decision unit  112  specifies, for example, “67(%)” as the ratio of the information whose substance matches from within the information acquired by the process at S 31 . 
     In the case where it is decided that the ratio specified by the process at S 41  is not equal to or higher than the threshold value (NO at S 42 ), the association decision unit  112  reflects information indicating that the pieces of information acquired by the process at S 31  are not associated with each other on the match information  136  stored in the information storage region  130  (S 43 ). Thereafter, the association decision unit  112  performs the processes at the steps beginning with S 24  again. 
     It is to be noted that the association decision unit  112  may perform the process at S 42  by referring to the setting information  132  stored in advance in the information storage region  130 . In the following, a particular example of the setting information  132  is described. 
     [Particular Example of Setting Information] 
       FIG. 26  is a view illustrating a particular example of the setting information  132 . 
     The setting information  132  depicted in  FIG. 26  includes “item number” for identifying each piece of information included in the setting information  132 , “name” to which a name of each piece of information is set, “value” to which a value of each piece of information is set, and “description” to which description of each piece of information is set. 
     For example, in the setting information  132  depicted in  FIG. 26 , to information whose “item number” is “1,” “match rate” is set as “name,” “65(%)” is set as “value,” and “match rate of substance of context” is set as “description.” 
     Therefore, in the process at S 42 , the association decision unit  112  may use, for example, “65(%)” set in “value” of the information to whose “name” “match rate” is set (information whose “item number” is “1”) as the threshold value. 
     Referring back to  FIG. 16 , in the case where the specified ratio is equal to or higher than the threshold value (YES at S 42 ), the first item specification unit  113  of the information processing apparatus  1  refers to the item information  134  stored in the information storage region  130  and specifies one combination of item names corresponding to the context IDs of the information acquired by the process at S 31  (S 44 ). 
     For example, in the case where the information set to “value” of the information to whose “name” “match ratio” is set in the setting information  132  as described with reference to  FIG. 26  is “65(%)” and the ratio specified by the process at S 41  is “67(%),” the first item specification unit  113  decides that the ratio specified by the process at S 41  is equal to or higher than the threshold value and performs the process at S 44 . 
     Further, in the first item information  134   a  described with reference to  FIG. 19A , “SalesDom” and “SalesFor” are set to “item name” of the pieces of information whose “context ID” is “C1” (information whose “item number” is “1” and “3”). Further, in the second item information  134   b  described with reference to  FIG. 19B , “Sales” is set to “item name” of the information whose “context ID” is “C2” (information whose “item number” is “1”). Therefore, the first item specification unit  113  specifies “SalesDom” and “Sales,” for example, by the process at S 44 . 
     Thereafter, the association decision unit  112  decides whether or not the item names specified by the process at S 44  match with each other (S 45 ). 
     In the case where it is decided that the item names specified by the process at S 44  match with each other (YES at S 46 ), the association decision unit  112  performs the processes at the steps beginning with step S 34  again. 
     For example, in this case, the association decision unit  112  decides that the pieces of information included in the combination acquired by the process at S 31  are pieces of information associated with each other (same information for which change of the substance has been performed). 
     On the other hand, in the case where it is decided that the item names specified by the process at S 44  do not match (No at S 46 ), the association decision unit  112  refers to the taxonomy information  135  stored in the information storage region  130  and specifies the item names of ancestor items (ancestor items including parent items) of the item names included in the combination specified by the process at S 44  as depicted in  FIG. 17  (S 51 ). 
     Then, the association decision unit  112  decides whether or not, in the item names of the ancestor item corresponding to one of the item names included in the combination specified by the process at S 44 , an item name that matches with the other item name exists (S 52 ). 
     For example, the association decision unit  112  decides whether or not, in the item names of ancestor items specified by referring to the first taxonomy information  135   a  by the process at S 51 , an item name that matches with the item name specified by referring to the second item information  134   b  by the process at S 44  exists or whether or not, in the item names of the ancestor items specified by referring to the second taxonomy information  135   b  by the process at S 51 , an item name that matches with the item name specified by referring to the first item information  134   a  by the process at S 44  exists. 
     For example, in the first taxonomy information  135   a  described with reference to  FIG. 20 , “Sales” is set in “presentation link parent” of the information whose “item name” is “SalesDom.” Therefore, in the case where, for example, the item name specified from the first item information  134   a  by the process at S 51  is “SalesDom” and the item name specified from the second item information  134   b  by the process at S 51  is “Sales,” the association decision unit  112  decides that the item name of the parent item corresponding to the item name specified from the first item information  134   a  and the item name specified from the second item information  134   b  match with each other. 
     For example, even in the case where the substances of pieces of information included in the combination acquired by the process at S 31  are different from each other, in the case where the ratio of information included in common in the pieces of information satisfies a given condition and it is decided that a given commonality exists between the item names of the items that refer to the pieces of information, the association decision unit  112  estimates that the pieces of information acquired by the process at S 31  are associated with each other. 
     Consequently, even in the case where the context ID of a context is changed or a plurality of contexts similar to a context exist, the information processing apparatus  1  may perform specification (estimation) of a context to be associated with each context. 
     In the case where, in the item names of the ancestor items corresponding to the one item name, an item name that matches with the other item name exists (YES at S 52 ), the second item specification unit  114  of the information processing apparatus  1  decides whether or not, in the information acquired from the second document information  131   b  (second context information  133   b ) by the process at S 31 , information that is not included in the information acquired from the first document information  131   a  (first context information  133   a ) by the process at S 31  is included (S 53 ). 
     For example, in the first context information  133   a  described with reference to  FIG. 18A , “date: 2016/6/15˜” and “product: Software” are set in “substance” to whose “context ID” “C1” is set. Further, in the second context information  133   b  described with reference to  FIG. 18B , “date: 2017/6/29˜,” “product: Software” and “district: Domestic” are set in “substance” of the information to whose “context ID” “C2” is set. Therefore, in this case, the second item specification unit  114  specifies “district: Domestic” as information that is included in the information acquired from the second document information  131   b  by the process at S 31  but is not included in the information acquired from the first document information  131   a  by the process at S 31 . 
     If it is decided as a result of decision by the process at S 53  that such information is not included (NO at S 54 ), the association decision unit  112  performs the processes at the steps beginning with S 34  again. 
     On the other hand, in the case where it is decided by the process at S 53  that such information is not included (NO at S 54 ), the second item specification unit  114  refers to the taxonomy information  135  stored in the information storage region  130  and decides whether or not the label of the information decided to be included by the process at S 53  is included in the label of the item name specified by the process at S 44  (S 55 ). 
     For example, in the second taxonomy information  135   b  described with reference to  FIG. 21 , “domestic” is set in “label” of the information to whose “item name” “Domestic” is set. Therefore, in the case where the information decided to be included by the process at S 53  is “district: Domestic,” the second item specification unit  114  specifies “domestic” as the label of the information decided to be included by the process at S 53 . Further, in the first taxonomy information  135   a  described with reference to  FIG. 20 , “amount of sales” and “amount of domestic sales” are set to the labels of the information to whose “item name” “Sales” and “SalesDom” are set, respectively. Further, in “amount of domestic sales” that is the label of “SalesDom,” “domestic” that is the label of “district: Domestic” is included. Therefore, in this case, the first item specification unit  113  decides that the label of the information decided to be included by the process at S 53  is included in the label of the item name specified by the process at S 44 . 
     In the case where it is decided that the label of the information decided to be included by the process at S 53  is included in the label of the item name specified by the process at S 44  (YES at S 56 ), the association decision unit  112  performs the processes at the steps beginning with S 34  again. 
     For example, in this case, the association decision unit  112  decides that the pieces of information included in the combination acquired by the process at S 31  are pieces of information associated with each other (same information for which change of the substance has been performed). 
     Consequently, it becomes possible for the association decision unit  112  to further increase the probability by which pieces of information acquired by the process at S 31  match with each other. 
     On the other hand, in the case where it is decided that the label of the information decided to be included by the process at S 53  is not included in the label of the item name specified by the process at S 44  (NO at S 56 ), the association decision unit  112  decides whether or not all combinations of item names corresponding to the context IDs of the information acquired by the process at S 31  are specified already by the process at S 44  (S 57 ). Also in the case where, in the item names of the ancestor items corresponding to the one item name, an item name that matches with the other item name does not exist (YES at S 52 ), the association decision unit  112  performs the process at S 57  similarly. 
     As a result, in the case where it is decided that all combinations of item names corresponding to the context IDs of the information acquired at S 31  are not specified as yet (NO at S 57 ), the first item specification unit  113  performs the processes at the steps beginning with S 44  again. 
     For example, in the first item information  134   a  described with reference to  FIG. 19A , “SalesDom” and “SalesFor” are set in “item name” of the pieces of information whose “context ID” is “C1” (information whose “item number” is “1” and “3”). Further, in the second item information  134   b  described with reference to  FIG. 19B , “Sales” is set in “item name” of the information whose “context ID” is “C2” (information whose “item number” is “1”). Therefore, the first item specification unit  113  specifies “SalesFor” and “Sales,” for example, by the process at S 44  that is performed again. 
     On the other hand, in the case where it is decided that all of the item names corresponding to the context IDs of the information acquired at S 31  are specified already (YES at S 57 ), the association decision unit  112  performs the processes at the steps beginning with S 43 . 
     For example, in this case, the association decision unit  112  decides that the pieces of information included in the combination acquired by the process at S 31  are not pieces of information that are not associated with each other. In the following, a particular example of the match information  136  finally generated in response to execution of the decision process is performed. 
     [Particular Example of Match Information Outputted by Process at S 26 ] 
       FIG. 27  is a view illustrating a particular example of the match information  136  outputted by the process at S 26 . For example,  FIG. 27  is a view illustrating a particular example of the match information  136  finally generated in response to execution of the decision process. 
     For example, in the case where it is decided that a context whose context ID is “C1” and another context whose context ID is “C2” are associated with each other, the association decision unit  112  sets “associated (decision process)” indicating that it is decided by the decision process that the contexts are associated with each other to “comparison result” of the information to whose “comparison source context” and “comparison destination context” “C1” and “C2” are set (information whose “item number” is “1”), respectively, as depicted in  FIG. 27 . 
     On the other hand, for example, in the case where it is decided that contexts whose context ID is “C3” and “C4” are associated with each other, the association decision unit  112  sets “not associated (decision process)” indicating that it is decided by the decision process that the contexts are not associated with each other to “comparison result” of the information to whose “comparison destination context” “C3” is set (information whose “item number” is “2”) and the information to whose “comparison source context” “C4” is set (information whose “item number” is “3”) as depicted in  FIG. 27 . 
     In this manner, the information processing apparatus  1  in the present embodiment accepts a comparison source context relating to an item included in the first document information  131   a  and a comparison destination context relating to an item included in the second document information  131   b.    
     Then, the information processing apparatus  1  refers to the information storage region  130 , which stores information that associates the information that specifies the items included in the first document information  131   a  with the contexts relating to the items and the information that associates the information that specifies the items included in the second document information  131   b  with the contexts relating to the items, and specifies a first item associated with the comparison source context and a second item associated with the comparison destination context. 
     Then, the information processing apparatus  1  refers to the information storage region  130  having stored therein the information that indicates a relationship between the items included in the first document information  131   a  and the information that indicates a relationship between the items included in the second document information  131   b  and specifies a third item having a specific relationship with the first item and a fourth item having a specific relationship with the second item. 
     Further, the information processing apparatus  1  decides based on the consistency between the third item and the fourth item whether or not the comparison destination context is associated with the comparison source context. 
     For example, the information processing apparatus  1  generates, for example, from information included in the first document information  131   a  and the second document information  131   b  stored in the information storage region  130 , information indicative of an item that refers to each context and information indicative of a relationship between the items. Then, the information processing apparatus  1  estimates, based on the information indicative of an item that refers to each context and information indicative of a relationship between the items, an association relationship between the comparison source context (context included in the first document information  131   a ) and the comparison destination context (context included in the second document information  131   b ). 
     Accordingly, it becomes possible for the information processing apparatus  1  to perform specification of a context to be associated with each context even in the case where the context ID of a context is changed or a plurality of contexts similar to a context exist. 
     It is to be noted that the association decision unit  112  may decide by the process at S 14  that all pieces of information including pieces of information whose context IDs match with each other are not associated with each other. 
     For example, the association decision unit  112  may generate even in the case where a context whose context ID is “C5” is included in both the first context information  133   a  and the second context information  133   b  as depicted in  FIG. 28 , information to whose “comparison source context ID” “C5” is set (information whose “item number” is “5”) and information to whose “comparison destination context ID” “C5” is set (information whose “item number” is “6”) and sets “not associated” to “comparison result” of both generated pieces of information. 
     Then, the association decision unit  112  may perform a succeeding process of the decision process in a state in which it is not finally determined that the context whose context ID is “C5” included in the first context information  133   a  and the context whose context ID is “C5” included in the second context information  133   b  are contexts associated with each other. 
     Consequently, it becomes possible for the information processing apparatus  1  to suppress such a situation that, for example, even in the case where context IDs of contexts that originally are not associated with each other match with each other as a result of a change of information, the contexts are associated with each other. 
     According to the above-mentioned embodiments, it is made possible to specify an association relationship between attributes included in documents different from each other. 
     All examples and conditional language provided herein are intended for the pedagogical purposes of aiding the reader in understanding the invention and the concepts contributed by the inventor to further the art, and are not to be construed as limitations to such specifically recited examples and conditions, nor does the organization of such examples in the specification relate to a showing of the superiority and inferiority of the invention. Although one or more embodiments of the present invention have been described in detail, it should be understood that the various changes, substitutions, and alterations could be made hereto without departing from the spirit and scope of the invention.