Abstract:
In a tag organization method a plurality of tags are received for tagging network resources. A range of resources tagged by each tag is determined for generating a hierarchical relationship network of tags according to the range of resources tagged by each tag. The hierarchical relationship network serves a graphical guide to facilitate resource searches, adjustment of search scope, to improve recall and precision, and ameliorate basic tag differences.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The invention relates to computer techniques, and more particularly to tag organization methods. 
         [0003]    2. Description of the Related Art 
         [0004]    As Web 2.0 concepts are introduced, websites, such “Del.icio.us”, are increasingly utilizing folksonomy methodology. Unlike taxonomies where resources are classified by professionals or authors, folksonomy allows users to classify websites, files, digital images, and other resources. Tags are keywords or descriptive expressions utilized to label resources.  FIG. 1  shows an example of a TagCloud. 
         [0005]    In  FIG. 1 , the greater the font size of a tag, the more resources the tag represents. A web server may utilize a webpage to receive a tag, a URL (uniform resource locator) of a resource labeled by the tag, description and notes about the resource, and add the tag to the TagCloud. When the tag is selected, the web server redirects a user to the resource. 
         [0006]    An identical tag may target irrelevant resource objects. For example, MIT may represent both “Made in Taiwan” and “Massachusetts Institute of Technology”. This problem may diminish search precision. Different tags may also target identical objects. For example, tags “cat” and “cats” may label the same webpage, and tags “New York” and “New_York” may both represent a resource New York City. Tags may be synonyms or relatives, such as relevant tags “perl”, “javascript”, and “programming”, or relevant tags “java”, “jdk” and “j2ee”. This further diminishes search recall. 
       BRIEF SUMMARY OF THE INVENTION 
       [0007]    Tag organization methods are provided. An exemplary embodiment of a tag organization method comprises the following steps. A plurality of tags for tagging network resources is received. The range of resources tagged by each tag is determined. A hierarchical relationship network of the tags is generated according to the determined range of each tag. Nodes in the network respectively represent the tags. The hierarchical relationship network facilitates resource searches. 
         [0008]    Tag organization systems are provided. An exemplary embodiment of a tag organization system comprises a tag handler, an organizer, and a search module. The tag handler receives a plurality of tags for tagging network resources. The organizer determines the range of resources tagged by each tag, generates a hierarchical relationship network of the tags according to the determined range of each tag. Nodes in the network respectively represent the tags. The search module utilizes the hierarchical relationship network to facilitate resource searches. 
         [0009]    An exemplary embodiment of a tag organization method comprises the following steps. A plurality of tags for tagging network resources, comprising a first tag and a second tag, is received. The resource set tagged by each tag is identified. When the first and second tags respectively correspond to resource sets O A  and O B  with common resources, and the set O A  is greater than set O B , and the proportion of the common resources in the set O B  is greater than a predetermined ratio, it is determined that the second tag belongs to the first tag. 
         [0010]    Tag organization methods and systems may be implemented by a computer application stored on a storage medium such as a memory or a memory device. The computer application, when loaded into a computer, directs the computer to execute the previously-described method. 
         [0011]    A detailed description is given in the following embodiments with reference to the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]    The invention can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein: 
           [0013]      FIG. 1  is a schematic view of a TagCloud; 
           [0014]      FIG. 2  is a block diagram of the configuration of an exemplary embodiment of a tag organization system; 
           [0015]      FIGS. 3   a ˜ 3   j  are schematic views of an exemplary embodiment of a hierarchical relationship network; 
           [0016]      FIG. 4  is a flowchart of an exemplary embodiment of a tag organization method; 
           [0017]      FIG. 5  a flowchart of an exemplary embodiment of a method for constituting a hierarchical relationship network of tags; 
           [0018]      FIG. 6  is a schematic view of an exemplary embodiment of a hierarchical relationship network with weighted links; and 
           [0019]      FIG. 7  is a schematic view of a network system comprising a plurality of computers. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0020]    The following description is of the best-contemplated mode of carrying out the invention. This description is made for the purpose of illustrating the general principles of the invention and should not be taken in a limiting sense. The scope of the invention is best determined by reference to the appended claims. 
         [0021]    Tag organization methods and systems are provided in the following. An exemplary embodiment of a tag organization method comprises tag acquisition, classification, data search assistance, searching, and search result ranking and arrangement. 
         [0022]      FIG. 2  shows an exemplary embodiment of a tag organization system. 
         [0023]    With reference to  FIGS. 2 and 4 , modules in sections  110 ,  120 , and  130  respectively organize and process tags, and search resources. Section  140  comprises graphical user interfaces (GUIs), comprising tag interface  141  and search interface  142 . Tag handler  111  receives and inputs a tag and corresponding resources (such as web pages, pictures, documents, and other network resources) through tag interface  141  tag repository  121  (step S 400 ). Organizer  122  determines the range of resources labeled by each tag (step S 402 ) and builds relationships between tags in tag repository  121  based on the determined range corresponding to each tag, and makes tags in tag repository  121  nodes in the relationship network (referred to as hierarchical relationship network H) (step S 404 ). Modules in section  130  utilize a hierarchical relationship network H to facilitate resource searches (step S 406 ). For example, search module  131  receives and utilizes strings or keywords through interface  142 , to search, locate and store search results to buffer  132 . Arrangement module  133 , utilizing the hierarchical relationship network calculates information density index for each instance of a network resource in the search results, sorts the network resources based on the information density index thereof, and stores the sorted resources to buffer  132 . Output module  150  displays sorted network resources in the search results. Search module  131  may display a hierarchical relationship network H or certain nodes thereof through search interface  142  to facilitate resource searches. 
         [0024]    The following table  1  shows the relationship between exemplary tags and resources, wherein any number common to a tag and a resource is the number of times tag handler  111  receives the same tag for labeling the same resource. 
         [0000]    
       
         
               
               
             
               
               
               
               
               
               
               
             
           
               
                   
                 TABLE 1 
               
             
             
               
                   
                   
               
               
                   
                 Resource 
               
             
          
           
               
                   
                 First step to 
                 Encyclopedia 
                 J2ME 
                   
                 C# step 
                 Java &amp; 
               
               
                 Tag 
                 Java 
                 of PHP 
                 intro 
                 Programming 
                 by step 
                 J2ME 
               
               
                   
               
               
                 Sun 
                 22 
                 00 
                 11 
                 21 
                 00 
                 05 
               
               
                 programming 
                 94 
                 27 
                 00 
                 33 
                 12 
                 01 
               
               
                 Java 
                 45 
                 00 
                 21 
                 04 
                 24 
                 23 
               
               
                 JDK 
                 21 
                 00 
                 00 
                 11 
                 00 
                 12 
               
               
                 J2SE 
                 00 
                 00 
                 00 
                 02 
                 13 
                 01 
               
               
                 C# 
                 00 
                 01 
                 00 
                 00 
                 44 
                 03 
               
               
                 J2ME 
                 00 
                 00 
                 06 
                 03 
                 00 
                 00 
               
               
                 J2EE 
                 00 
                 00 
                 34 
                 01 
                 00 
                 23 
               
               
                 PHP 
                 00 
                 48 
                 00 
                 00 
                 00 
                 00 
               
               
                 Javascript 
                 01 
                 44 
                 00 
                 01 
                 00 
                 00 
               
               
                 API 
                 13 
                 12 
                 14 
                 34 
                 11 
                 00 
               
               
                 JSP 
                 31 
                 00 
                 00 
                 07 
                 00 
                 00 
               
               
                   
               
             
          
         
       
     
         [0025]    Table 1 may be represented by the following matrix R corresponding to the tags and resources: 
         [0000]    
       
         
           
             
               
                 
                   R 
                   = 
                   
                      
                     
                       
                         
                           22 
                         
                         
                           0 
                         
                         
                           11 
                         
                         
                           21 
                         
                         
                           0 
                         
                         
                           5 
                         
                       
                       
                         
                           94 
                         
                         
                           27 
                         
                         
                           0 
                         
                         
                           33 
                         
                         
                           12 
                         
                         
                           1 
                         
                       
                       
                         
                           45 
                         
                         
                           0 
                         
                         
                           21 
                         
                         
                           4 
                         
                         
                           24 
                         
                         
                           23 
                         
                       
                       
                         
                           21 
                         
                         
                           0 
                         
                         
                           0 
                         
                         
                           11 
                         
                         
                           0 
                         
                         
                           12 
                         
                       
                       
                         
                           0 
                         
                         
                           0 
                         
                         
                           0 
                         
                         
                           2 
                         
                         
                           13 
                         
                         
                           1 
                         
                       
                       
                         
                           0 
                         
                         
                           1 
                         
                         
                           0 
                         
                         
                           0 
                         
                         
                           44 
                         
                         
                           3 
                         
                       
                       
                         
                           0 
                         
                         
                           0 
                         
                         
                           6 
                         
                         
                           3 
                         
                         
                           0 
                         
                         
                           0 
                         
                       
                       
                         
                           0 
                         
                         
                           0 
                         
                         
                           34 
                         
                         
                           1 
                         
                         
                           0 
                         
                         
                           23 
                         
                       
                       
                         
                           0 
                         
                         
                           48 
                         
                         
                           0 
                         
                         
                           0 
                         
                         
                           0 
                         
                         
                           0 
                         
                       
                       
                         
                           1 
                         
                         
                           44 
                         
                         
                           0 
                         
                         
                           1 
                         
                         
                           0 
                         
                         
                           0 
                         
                       
                       
                         
                           13 
                         
                         
                           12 
                         
                         
                           14 
                         
                         
                           34 
                         
                         
                           11 
                         
                         
                           0 
                         
                       
                       
                         
                           31 
                         
                         
                           0 
                         
                         
                           0 
                         
                         
                           7 
                         
                         
                           0 
                         
                         
                           0 
                         
                       
                     
                      
                   
                 
               
               
                 
                   ( 
                   1 
                   ) 
                 
               
             
           
         
       
     
         [0026]    R ij  is the number of times the ith tag is used as a label for the jth resource, 
         [0000]    wherein i and j are integers, and 0≦i&lt;12, 0≦j&lt;6. Organizer  122  may treat the number of resource instances labeled by a tag as the corresponding range of the tag. Thus, organizer  122  can accordingly determine the corresponding range of each tag. For example, the tag “Sun” labels five resource instances: “First step to Java”, “J2ME intro”, “Programming”, “C# step-by-step”, and “Java &amp; J2ME”. The tag JDK labels comprises only three of the described labels. Thus, the corresponding range of the tag “Sun” is greater than that of tag “JDK”. 
         [0027]    Organizer  122  makes each tag a node in hierarchical relationship network H according to the corresponding range of each tag. First, organizer  122  sorts the tags based on the corresponding range of each tag. The statistic data of the number of resource instances is shown in Table 2: 
         [0000]    
       
         
               
               
             
               
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
               
             
           
               
                   
                   
               
               
                   
                 resource 
               
             
          
           
               
                   
                 First 
                   
                   
                   
                 C# 
                   
                   
                   
               
               
                   
                 step 
                   
                   
                   
                 step 
               
               
                   
                 to 
                 Encyclopedia 
                 J2ME 
                   
                 by 
                 Java &amp; 
                 resource 
                 Times 
               
               
                 tag 
                 Java 
                 of PHP 
                 intro 
                 Programming 
                 step 
                 J2ME 
                 instance 
                 used 
               
               
                   
               
             
          
           
               
                 Sun 
                 22 
                 00 
                 11 
                 21 
                 00 
                 05 
                 4 
                 59 
               
               
                 programming 
                 94 
                 27 
                 00 
                 33 
                 12 
                 01 
                 5 
                 167 
               
               
                 Java 
                 45 
                 00 
                 21 
                 04 
                 24 
                 23 
                 5 
                 177 
               
               
                 JDK 
                 21 
                 00 
                 00 
                 11 
                 00 
                 12 
                 3 
                 44 
               
               
                 J2SE 
                 00 
                 00 
                 00 
                 02 
                 13 
                 01 
                 3 
                 16 
               
               
                 C# 
                 00 
                 01 
                 00 
                 00 
                 44 
                 03 
                 3 
                 47 
               
               
                 J2ME 
                 00 
                 00 
                 06 
                 03 
                 00 
                 00 
                 2 
                 9 
               
               
                 J2EE 
                 00 
                 00 
                 34 
                 01 
                 00 
                 23 
                 3 
                 58 
               
               
                 PHP 
                 00 
                 48 
                 00 
                 00 
                 00 
                 00 
                 1 
                 48 
               
               
                 Javascript 
                 01 
                 44 
                 00 
                 01 
                 00 
                 00 
                 3 
                 46 
               
               
                   
               
             
          
         
       
     
         [0028]    The number of resource instances corresponding to each tag is the number of nonzero items in the same row as the tag in Table 1. The times used corresponding to each tag is the total number of times the tag is used as a label for the resources in the same row as the tag. Organizer  122  sorts the tags based on the number of resource instances corresponding to each tag, and if two or more tags corresponding to the same number of resource instances, further sorts these tags according to the corresponding times used . If two or more tags corresponding to the same number of resource instances and the same times used, organizer  122  further sorts the tags based on the times the tags are entered to system  100  respectively. The sort result is shown in table 3: 
         [0000]      &lt; CWU −Call number=“24”/&gt; 
         [0000]    
       
         
               
               
               
               
               
               
               
               
               
               
             
           
               
                   
                 TABLE 3 
               
               
                   
                   
               
             
             
               
                   
                 JSP 
                 31 
                 00 
                 00 
                 07 
                 00 
                 00 
                 2 
                 38 
               
               
                   
                 J2ME 
                 00 
                 00 
                 06 
                 03 
                 00 
                 00 
                 2 
                  9 
               
               
                   
                 PHP 
                 00 
                 48 
                 00 
                 00 
                 00 
                 00 
                 1 
                 48 
               
               
                   
                   
               
             
          
         
       
     
         [0029]    The sorted tags are respectively “programming”, “Java”, “API”, “Sun”, “J2EE”, “C#”, “Javascript”, “JDK”, “J2SE”, “JSP”, “J2ME”, and “PHP”, which are added sequentially to hierarchical relationship network H. 
         [0030]    Organizer  122  may generate table 4 from table 3, in which the relationships between tags and resources are represented as binary numbers: 
         [0000]    
       
         
               
               
             
               
               
               
               
               
               
               
             
           
               
                   
                 TABLE 4 
               
             
             
               
                   
                   
               
               
                   
                 resource 
               
             
          
           
               
                   
                   
                   
                   
                   
                 C# 
                   
               
               
                   
                   
                   
                   
                   
                 step 
               
               
                   
                 First step to 
                 Encyclopedia 
                 J2ME 
                   
                 by 
                 Java &amp; 
               
               
                 tag 
                 Java 
                 of PHP 
                 intro 
                 Programming 
                 step 
                 J2ME 
               
               
                   
               
               
                 programming 
                 1 
                 1 
                 0 
                 1 
                 1 
                 1 
               
               
                 Java 
                 1 
                 0 
                 1 
                 1 
                 1 
                 1 
               
               
                 API 
                 1 
                 1 
                 1 
                 1 
                 1 
                 0 
               
               
                 Sun 
                 1 
                 0 
                 1 
                 1 
                 0 
                 1 
               
               
                 J2EE 
                 0 
                 0 
                 1 
                 1 
                 0 
                 1 
               
               
                 C# 
                 0 
                 1 
                 0 
                 0 
                 1 
                 1 
               
               
                 Javascript 
                 1 
                 1 
                 0 
                 1 
                 0 
                 0 
               
               
                 JDK 
                 1 
                 0 
                 0 
                 1 
                 0 
                 1 
               
               
                 J2SE 
                 0 
                 0 
                 0 
                 1 
                 1 
                 1 
               
               
                 JSP 
                 1 
                 0 
                 0 
                 1 
                 0 
                 0 
               
               
                 J2ME 
                 0 
                 0 
                 1 
                 1 
                 0 
                 0 
               
               
                 PHP 
                 0 
                 1 
                 0 
                 0 
                 0 
                 0 
               
               
                   
               
             
          
         
       
     
         [0031]    “1” stands for the existence of a corresponding tag and resource instance, and “0” stands for their absence. The following matrix M can be utilized to represent table 4 and the relationships between tags and resources: 
         [0000]    
       
         
           
             
               
                 
                   M 
                   = 
                   
                      
                     
                       
                         
                           1 
                         
                         
                           1 
                         
                         
                           0 
                         
                         
                           1 
                         
                         
                           1 
                         
                         
                           1 
                         
                       
                       
                         
                           1 
                         
                         
                           0 
                         
                         
                           1 
                         
                         
                           1 
                         
                         
                           1 
                         
                         
                           1 
                         
                       
                       
                         
                           1 
                         
                         
                           1 
                         
                         
                           1 
                         
                         
                           1 
                         
                         
                           1 
                         
                         
                           0 
                         
                       
                       
                         
                           1 
                         
                         
                           0 
                         
                         
                           1 
                         
                         
                           1 
                         
                         
                           0 
                         
                         
                           1 
                         
                       
                       
                         
                           0 
                         
                         
                           0 
                         
                         
                           1 
                         
                         
                           1 
                         
                         
                           0 
                         
                         
                           1 
                         
                       
                       
                         
                           0 
                         
                         
                           1 
                         
                         
                           0 
                         
                         
                           0 
                         
                         
                           1 
                         
                         
                           1 
                         
                       
                       
                         
                           1 
                         
                         
                           1 
                         
                         
                           0 
                         
                         
                           1 
                         
                         
                           0 
                         
                         
                           0 
                         
                       
                       
                         
                           1 
                         
                         
                           0 
                         
                         
                           0 
                         
                         
                           1 
                         
                         
                           0 
                         
                         
                           1 
                         
                       
                       
                         
                           0 
                         
                         
                           0 
                         
                         
                           0 
                         
                         
                           1 
                         
                         
                           1 
                         
                         
                           1 
                         
                       
                       
                         
                           1 
                         
                         
                           0 
                         
                         
                           0 
                         
                         
                           1 
                         
                         
                           0 
                         
                         
                           0 
                         
                       
                       
                         
                           0 
                         
                         
                           0 
                         
                         
                           1 
                         
                         
                           1 
                         
                         
                           0 
                         
                         
                           0 
                         
                       
                       
                         
                           0 
                         
                         
                           1 
                         
                         
                           0 
                         
                         
                           0 
                         
                         
                           0 
                         
                         
                           0 
                         
                       
                     
                      
                   
                 
               
               
                 
                   ( 
                   2 
                   ) 
                 
               
             
           
         
       
     
         [0032]    A vector M i  represents the tag vector of the ith tag. For example, the 0 th  tag “programming” has a tag vector [1 1 0 1 1 1]. 
         [0033]    Organizer  122  may utilizes the following arrays to generate hierarchical relationship network H:
       Tag[ ]: storing sorted tags not added to hierarchical relationship network H;   hierarchy[ ]: storing a copy of tags added to hierarchical relationship network H;   Terminal[ ]: storing tags added to hierarchical relationship network H having no child node;   Tag_Relation[ ][ ]: A relationship matrix, also a (0, 1)-matrix, in which Tag_Relation[x][y]=1 indicates that the xth tag is the child node of the yth tag, and x and y are both positive integer.       
 
         [0038]    Hierarchical Relationship Network Constitution: 
         [0039]    With reference to  FIG. 5 , organizer  122  executes the following steps. After sorting tags in repository  121  (step S 500 ), organizer  122  initializes hierarchical relationship network H (step S 502 ). As shown in  FIG. 3   a , organizer  122  inserts a root node S and a terminal node T to hierarchical relationship network H. The root node is assigned the parent node of any tags when the parent node thereof cannot be found through parent-child check operations. 
         [0040]    Node T links to leaf nodes, i.e. nodes without any child node. The tag vector of the root node S may be set as [1 1 1 1 1 1]. Terminal[ ] and hierarchy[ ]currently comprise only the root node S. 
         [0041]    Organizer  122  retrieves a tag from the sort result (tag “programming”) for adding to hierarchical relationship network H as a node (step S 504 ). For example, as shown in  FIG. 3   b , when processing the tag “programming” as a current node, organizer  122  assigns root node S as the parent node of the current node. 
         [0042]    Organizer  122  determines if any tag remains in Tag[ ] (step S 506 ). If no, organizer  122  outputs hierarchical relationship network H to network buffer  123  (step S 508 ). If yes, organizer  122  retrieves a tag Tag[x] as the current node from the sorted result Tag[ ] (step S 510 ). The x is an integer. Organizer  122  copies all nodes from hierarchical relationship network H to hierarchy[ ] (step S 512 ). 
         [0043]    Organizer  122  retrieves a node as the target node hierarchy[y] under check from hierarchical relationship network H according to the breadth first search (BFS) algorithm beginning from terminal node T of the hierarchical relationship network H (step S 514 ). The node is retrieved as the target node only when the node has a copy hierarchy[y] in hierarchy[ ]. The target node hierarchy[y] is then removed from hierarchy[ ] (step S 515 ). Organizer  122  performs a parent-child check on the current node Tag[x] and the target node hierarchy[y] to determines if the current node Tag[x] and the target node hierarchy[y] satisfy the a condition (step S 516 ): 
         [0044]    The current node Tag[x] and the target node hierarchy[y] may be respectively referred to as a first tag and a second tag for simplicity. The network resources tagged by the first tag and the second tag respectively comprise a set O A  and a set O B . In a parent-child check operation, a parent-child relationship may be built between the current node Tag[x] and the target node hierarchy[y] when the following formula is satisfied thereby: 
         [0000]    
       
         
           
             
               
                 
                   
                     
                        
                       
                         
                           O 
                           A 
                         
                         ⋂ 
                         
                           O 
                           B 
                         
                       
                        
                     
                     
                        
                       
                         O 
                         A 
                       
                        
                     
                   
                   ≥ 
                   λ 
                 
               
               
                 
                   ( 
                   3 
                   ) 
                 
               
             
           
         
       
     
         [0045]    wherein λ comprises a predetermined number, and is set to 0.8 in the following. |O A | is the number of network resource instances in the set O A , and |O A ∩ B | is the number of network resource instances in the intersection of sets O A  and O B . 
         [0046]    In step S 516 , organizer  122  performs a parent-child check on the current node Tag[x] and the target node hierarchy[y], in which when network resources commonly tagged by the first and second tags satisfy the formula (3), organizer  122  builds a parent-child relationship between the first and second tags (step S 518 ) and makes one of the first and second tags correspond to a greater range and the other correspond to a smaller range to be the parent node and the child node in the parent-child relationship respectively. A corresponding element in Tag_Relation[ ][ ] is set to “1”. If not, organizer  122  directly executes step S 522 . In step S 522 , organizer  122  determines if any tag exists in hierarchy[ ] (step S 522 ). If so, step S 514  is repeated. If not, step S 506  is repeated. The root node is assigned the parent node of a tag when the parent node thereof cannot be found through parent-child check operations. 
         [0047]    For example, when retrieving tag “java” as the current node, organizer  122  performs a parent-child check on tag “java” and tag “programming”. Then |O A |=5 and 
         [0000]    
       
         
           
             
               
                  
                 
                   
                     O 
                     A 
                   
                   ⋂ 
                   
                     O 
                     B 
                   
                 
                  
               
               
                  
                 
                   O 
                   A 
                 
                  
               
             
             = 
             
               0.8 
               ≥ 
               λ 
             
           
         
       
     
         [0000]    is obtained. Thus, as shown in  FIG. 3   c , organizer  122  builds a parent-child relationship (denoted as link L 1  in  FIG. 3   c ) between tag “java” and tag “programming” (step S 518 ) and making one of the two tags corresponding to a greater range and the other corresponding to a smaller range respectively the parent node and the child node in the parent-child relationship. Similarly, when retrieving tag “api” as the current node, organizer  122  obtains 
         [0000]    
       
         
           
             
               
                  
                 
                   
                     O 
                     A 
                   
                   ⋂ 
                   
                     O 
                     B 
                   
                 
                  
               
               
                  
                 
                   O 
                   A 
                 
                  
               
             
             = 
             
               0.8 
               ≥ 
               
                 λ 
                 . 
               
             
           
         
       
     
       Thus, tag “java” becomes the parent node of tag “api”. 
       [0048]    Note that when a checked target node (such as tag “java”) has been made the parent node of the current node (such as tag “api”), ancestor nodes (such as tag “programming”) of the target node is prevented from any further parent-child check with the same current node(such as tag “api”). Thus, organizer  122  removes the target node hierarchy[y] and all ancestor nodes thereof from hierarchy[ ] (step S 520 ). Conversely, when a checked target node is not the parent node of the current node, ancestor nodes of the target node are still required to receive parent-child checks with the same current node (such as tag “api”). 
         [0049]    For example, as shown in  FIG. 3   e , when organizer  122  retrieves tag “sun” as the current node and tag “api” as the target node, 
         [0000]    
       
         
           
             
               
                  
                 
                   
                     O 
                     A 
                   
                   ⋂ 
                   
                     O 
                     B 
                   
                 
                  
               
               
                  
                 
                   O 
                   A 
                 
                  
               
             
             = 
             
               
                 3 
                 4 
               
               = 
               
                 0.75 
                 &lt; 
                 λ 
               
             
           
         
       
     
         [0000]    is obtained, so tag “api” is not the parent node of tag “sun”. Further parent-child checks on tag “java” and tag “sun” are required. When organizer  122  retrieves tag “sun” as the current node and tag “java” as the target node, 
         [0000]    
       
         
           
             
               
                  
                 
                   
                     O 
                     A 
                   
                   ⋂ 
                   
                     O 
                     B 
                   
                 
                  
               
               
                  
                 
                   O 
                   A 
                 
                  
               
             
             = 
             
               1 
               &gt; 
               λ 
             
           
         
       
     
         [0000]    is obtained, so tag “java” is set as the parent node of tag “sun”. The ancestor nodes (such as tag “programming”) of the tag “java” is prevented from any further parent-child check with the same current node(tag “sun”). 
         [0050]    Similarly, with reference to  FIGS. 3   f ,  3   g ,  3   h , and  3   i , organizer  122  adds tag “j2ee”, “C#”, “javascript”, and “jdk” to hierarchical relationship network H and obtains  FIG. 3   j.    
         [0051]    Accordingly, constitution of hierarchical relationship network H comprises tag classification. Provided with tags A and B respectively corresponding to resource sets O A  and O B , when the following conditions is satisfied: 
         [0052]    (1). the corresponding range of tag A is greater than that of tag B, (i.e. |O A |&gt;|O B |), 
         [0053]    (2) tags A          B commonly correspond to common resources (i.e. O A ∩O B ≠Φ, where Φ is a null set), 
         [0054]    (3) the common resources contribute a greater proportion in set O B  than a predetermined proportion (such as λ), i.e. 
         [0000]    
       
         
           
             
               
                 
                    
                   
                     
                       O 
                       A 
                     
                     ⋂ 
                     
                       O 
                       B 
                     
                   
                    
                 
                 
                    
                   
                     O 
                     A 
                   
                    
                 
               
               ≥ 
               λ 
             
             , 
           
         
       
     
         [0055]    it is determined that tag B belongs to tag A. 
         [0056]    Assistance in Resource Search:Keyword Suggestion 
         [0057]    Search module  142  receives a keyword for resource search. When the keyword matches a specific tag (such as “java”) in the hierarchical relationship network H, guide module  112  retrieves nodes adjacent to the specific tag. Search module  142  provides optional keywords for the resource search by displaying tags represented by the adjacent nodes. When a displayed tag is selected, search module  142  searches for network resources utilizing the selected tag as a search key. 
         [0058]    Additionally, a parameter D may be utilized to configure the scope of nodes adjacent to the specific tag. For example, the parameter D is utilized to configure the distance between the specific tag and the nodes adjacent thereto, wherein each link is treated as one distance unit. When D=1, search module  131  displays tags one link away from the specific tag (including parent and child nodes thereof) through output module  150 . For example, tags one link away from the tag “java” comprise “Sun”, “Programming”, “api”, and “jsp”. When D=2, search module  131  displays tags two links away from the specific tag (including parent, child, grandfather, and grandson nodes thereof) through output module  150 . Tags two links away from the tag “java” further comprise “Javascript”, “l2ee”, “jdk”, “C#”, and “php”. The parameter D may be user adjustable. 
         [0059]    Search module  131  may directly display hierarchical relationship network H or the nodes therein alphabetically sorted in form of TagCloud. Search module  131  may determine the sizes of tags according to the times used thereof. 
         [0060]    Assistance in Resource Search:Search Result Ranking 
         [0061]    Search module  131  receives strings or keywords through interface  142 , utilizes the same for resource searches, locate and store search results to buffer  132 . Arrangement module  133  utilizes the hierarchical relationship network H to calculate information density index for each instance of the resources. Organizer  122  may assign weight to relationships (i.e. links in network H) between tags according to the following formula. Tag vectors A and B of two tags are taken as an example to calculate cosine similarity therebetween as the weight of the two tags: 
         [0000]    
       
         
           
             
               
                 
                   
                     A 
                     · 
                     B 
                   
                   
                     
                        
                       A 
                        
                     
                      
                     
                        
                       B 
                        
                     
                   
                 
               
               
                 
                   ( 
                   4 
                   ) 
                 
               
             
           
         
       
     
         [0062]    For example, the tag vector of tag “programming” is [ 1 1 0 1 1 1], the tag vector of tag “java” is [ 1 0 1 1 1 1], the tag vector of tag “API” is [ 1 1 1 1 1 0], the tag vector of tag “Sun” is [1 0 1 1 0 1], the tag vector of tag “J2EE” is [ 0 0 1 1 0 1], the tag vector of tag “C#” is [0 1 0 0 1 1], the tag vector of tag “JDK” is [1 0 0 1 0 1], and the tag vector of tag “JSP” is [1 0 0 1 0 0]. The weights of relationships between tags are shown in  FIG. 6 . 
         [0063]    The following is a formula for calculating information density index for each instance of resources: 
         [0000]    
       
         
           
             
               
                 
                   
                     ( 
                     
                       
                         ∑ 
                         
                           t 
                           = 
                           1 
                         
                         k 
                       
                        
                       S 
                     
                     ) 
                   
                   + 
                   
                     ( 
                     
                       
                         ∑ 
                         
                           i 
                           = 
                           1 
                         
                         n 
                       
                        
                       
                         ( 
                         
                           S 
                           * 
                           
                             W 
                             i 
                           
                         
                         ) 
                       
                     
                     ) 
                   
                   + 
                   
                     ( 
                     
                       
                         ∑ 
                         
                           j 
                           = 
                           1 
                         
                         m 
                       
                        
                       
                         ( 
                         
                           S 
                           * 
                           
                             W 
                             j 
                           
                         
                         ) 
                       
                     
                     ) 
                   
                 
               
               
                 
                   ( 
                   5 
                   ) 
                 
               
             
           
         
       
     
         [0064]    S: the grade obtained when a located resource instance matches a tag utilized as a search key; 
         [0065]    W i : the weight between the search key tag and a parent node and/or child nodes thereof; 
         [0066]    W j : the weight between the search key tag and a grandfather node and/or grandson nodes thereof; 
         [0067]    k, n, m: the located resource instance matches k tags, n parent/child nodes, and m grandfather/grandson nodes. 
         [0068]    Thus, according to formula (5), when S=1, and a resource instance matches keyword “java”, the grade of information density index obtained is: 
         [0000]      (1)+(0.75+0.43+0.51.0.72)+(0.38+0.87). 
         [0069]    Arrangement module  133  may calculate information density index for resource instances in the search result according to formula (5), sort the resources based on the calculated information density index thereof, and store the sorted resources to buffer  132 . Output module  150  displays the sorted network resources. 
         [0070]    The tag organization method may be implemented by a computer program stored in a computer-readable storage medium. With reference to  FIG. 7 , system  100  may comprise a computer program executed by server  700 . Memory  2  stores system  100  which, when loaded to server  700 , directs processor  1  to execute the tag organization method. System  100  may be loaded to memory  2  of server  700  though cables or wireless communication channels from a disc, a hard disk, a portable disk drive, or other storage media. 
         [0071]    Server  700  may be coupled to client computers C through a network. Client computers C input tags to system  100  through web browsers, and displays suggested optional tags, hierarchical relationship network H, and search results. 
         [0072]    In conclusion, the tag organization system builds and provides a hierarchical relationship network of tags as the interface for resource searches, by which search scope can be adjusted by selecting tags at different levels of the hierarchical relationship network. 
         [0073]    While the invention has been described by way of example and in terms of preferred embodiment, it is to be understood that the invention is not limited thereto. To the contrary, it is intended to cover various modifications and similar arrangements (as would be apparent to those skilled in the art). Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements.