Abstract:
A system for displaying the results of a search provided by one of two different search systems enabling continuous searching. One search system includes a search takeover data production command used to output search takeover data articles from the search. The other search system includes a search takeover data reading command used to read search takeover data. A document identifier correspondence table associates the identifiers specified in the search takeover data. When a user clicks a search system transfer instruction button in one search system, the search takeover data producing command is executed to produce search takeover data which is passed to the other search system. The latter search system regards the list of identifiers of articles which was passed by the search takeover data reading command as the search results, and thus operates continuously.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a user interface for use in searching documents. 
   2. Description of the Related Art 
   Generally, a document search system includes a unique interface. Even when a general-purpose World Wide Web (WWW) browser can be used by utilizing a common gateway interface (CGI) technology, an operating procedure or a way of displaying the results of research differs from search system to search system. It can therefore be said that search systems (interfaces) are different from one another. Each search system is characterized by a value-added feature that may be a processing speed, a way of graphically displaying the results of search, or an ability to summarize the results of search. A user selects a search system, of which features are helpful for the user to most efficiently search intended information, according to the contents of search. 
   For example, assume that there are two different search systems for searching the same document database. Search system A can search for documents with reference to, in addition to a keyword, meta-information including an author of documents and a date of production. In contrast, search system B searches documents according to a keyword alone and has the ability to produce and display an overview of the results of search. 
   When search system A is used to search the document database, a user can effectively find a group of documents, which meets a search request, by designating the meta-information of a desired document. However, it is not easy for the user to summarize the documents. When a user uses the search system B to check the overview of the group of documents found by the search system A, the user can efficiently grasp the tendency of all the results of search and can thus acquire very valuable information. 
   As mentioned above, it is often very useful to display the results of search, which a user has acquired using the search system A, using the other search system B. 
   In such a case, conventionally, a user issues an appropriate query to the search system B. The results of search acquired by the search system A at that time are then reproduced. If a kind of search key is different between two different search systems, the reproduction is very hard to do. Supposing a kind of search key required by one search system matches a kind of search key required by the other search system, a feature for designating conditions for search or a search algorithm may be different. Thus, there is generally difficulty in reproducing the results of search, which have been acquired using a certain search system, using another search system. 
   SUMMARY OF THE INVENTION 
   Accordingly, an object of the present invention is to provide a method for displaying the results of search provided by one of two different search systems using the other search system so as to enable continuous searching. 
   According to the present invention, a transfer button for use in designating search system (interface) B, to which a user transfers and which the user allows to take over the results of search, is displayed by search system A. 
   The search system A includes a search takeover data producing means that is used to output a list of identifiers of articles on the results of search which is written in a format understandable by the search system B. The search takeover data producing means is used to produce search takeover data that specifies the results of search which the search system B takes over and which is reported to the search system B to which a user transfers. 
   The search takeover data specifies the list of articles on the results of search. In order to designate an article, an article identifier, a uniform resource locator (URL), or any other thing with which an article can be identified and which the transfer-destination search system B can receive is used. 
   When a user clicks the transfer button, search takeover data that describes the results of search displayed by the search system A is produced and passed to the transfer-destination search system B. At this time, if necessary, the transfer-destination search system (interface) is also activated. 
   The transfer-destination search system regards articles specified in the received search takeover data as the results of search. Thus, the search system takes over the results of search provided by the search system A. 
   According to the present invention, a means is needed for automatically activating a transfer-destination search system (interface) and for if the search system has already been activated, designating the search system. Moreover, a means is needed for passing search takeover data to the transfer-destination search system (interface). A practical method varies depending on a platform (OS) on which a search system interface is run. According to the present invention, a platform having the above means shall be employed. 
   Other and further objects, features and advantages of the invention will appear more fully from the following description. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  shows an example of a basic configuration in which the present invention is implemented; 
       FIG. 2  shows a server-vs.-database correspondence table; 
       FIG. 3  shows an example of a structure of a search system interface; 
       FIG. 4  shows an example of a structure of a search system interface having a summary displaying feature; 
       FIG. 5  shows a table that is created in order to take over the results of search; 
       FIG. 6  describes a search takeover data producing means; 
       FIG. 7  describes a search takeover data writing means; 
       FIG. 8  describes a search system transfer instructing means; 
       FIG. 9  shows a search takeover record table; 
       FIG. 10  shows search system interface A from which a user transfers; 
       FIG. 11  shows search system interface B to which the user transfers (immediately after the transfer); 
       FIG. 12  shows the search system interface B to which the user transfers (after operation); 
       FIG. 13  shows search system interface C to which the user transfers; 
       FIG. 14  shows an example of an operating environment in which a database is used in common; 
       FIG. 15  shows an example of a normal search system program; 
       FIG. 16  shows a case (part) where a search system can receive and display search takeover data when being activated; and 
       FIG. 17  shows a case (part) where a search system can receive and display search takeover data when running. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   An embodiment will be described with reference to the drawings below. 
     FIG. 1  schematically shows an example of a system configuration in which the present invention is implemented. The system consists mainly of search system interfaces  20  and  30 , search system servers  40  and  50 , and a network  10 . The search system interfaces  20  and  30  are interfaces through which a user enters a search request or displays the results of search. The search system servers  40  and  50  execute search programs installed therein. The network  10  mediates in communications among the interfaces and servers. 
   The search system server  40  from which a user transfers includes a searching means, a document database that is an object of search, and a document identifier correspondence table. The document identifier correspondence table is used to associate document identifiers recorded in the document database with document identifiers recorded in a document database stored in a search system server to which the user transfers. 
   The search system server  50  to which the user transfers includes a searching means, a summarizing means, and a document database that is an object of search. 
   The searching means  401  or  501  included in the search system  40  or  50  searches the document database for a group of documents that exhibits a high degree of relevance to a search request which a user enters using a search request inputting means  201  or  301  included in the search system interface. The search system  40  or  50  then passes the group of documents to a results-of-search displaying means  203  or  304  included in the search system interface. The searching means is realized with, for example, a known keyword searching method. That is to say, a search request that is an input is a weighted set of words. The words are therefore regarded as weighted input keywords. Search is then carried out with the words ORed. At this time, the weight (degree of relevance) of a document to be searched for is calculated as mentioned below. For each word contained in both a search request and a document to be searched for, a weight (for example, frequency) of each word in the search request and a weight thereof in the document to be searched for are used to calculate a comprehensive weight (for example, a product between both the weights). The weights of all such words are added up (for example, a sum total of the weights is calculated), whereby the degree of relevance is obtained. 
   A summarizing means  502  included in the search system  50  summarizes the results of search. The term “summarizing” means that the results of search are displayed in a well-understandable manner. In this example, since a document is searched for, a set of words accurately expressing the contents of the document is regarded as a summary. As the summarizing means, an existing method described in JP-A No. 62963/1997 entitled “Method of Classifying Documents using Probability Model” can be adopted. 
   For instance, each document included in a group of documents to be summarized is divided into words, and the frequencies of the words are added up. Generally, a word that often appears in a group of documents represents the group of documents to a high degree. In other words, a word that appears in a group of documents at a high frequency is likely to be contained in a summary. However, a word that often appears in any document, such as, “perform” is inappropriate as a word for a summary. Therefore, normally, a word for a summary is selected in consideration of the frequency of appearance in a document database in which a group of documents is recorded. Specifically, a word whose frequency of appearance in a designated group of documents is high and whose comprehensive frequency of appearance in a document database is low is a characteristic word because it appears only in the group of documents concerned. The word is an appropriate word for a summary that characterizes the group of documents. More particularly, a function to which the frequencies of appearance at which words contained in a group of documents appear in the group of documents, and the frequencies of appearance thereof in a document database are assigned is used to calculate the weights of the words. Words whose weights are equal to or larger than a certain threshold are adopted as words for a summary. 
   The search system interface  20  from which a user transfers includes a search request inputting means, a results-of-search displaying means, a search system transferring means, and a search takeover data producing means. 
     FIG. 3  shows an example of a search system interface from which a user transfers. A user uses a document database selector  2013  to designate a document database to be searched, enters a search request in a keyword input box  2011 , and clicks a keyword search instruction button  2012 . Search is then carried out. The results of search are displayed using the results-of-search displaying means  203 . The contents of documents that are the results of search can be browsed by clicking a browse button  2021 . In this example, “DB 1 ” is designated as a document database that is an object of search, and “keyword  1 ” is entered as a search request. The results of search performed under these conditions are displayed. 
   The search system interface  30  to which the user transfers includes a search request inputting means, a results-of-search displaying means, a summary displaying means, and a search takeover data reading means. 
     FIG. 4  shows an example of a search system interface to which the user transfers. A user uses a document database selector  3013  to designate a document database to be searched, enters a search request in a keyword input box  3011 , and clicks a keyword search instruction button  3012 . Search is then started. The results of search are displayed using a results-of-search displaying means  302 . The results of search are displayed by a summary displaying means  303 . The contents of documents that are the results of search can be browsed by clicking a browse button  3021 . In this example, DB 1  is designated as a document database that is an object of search, and keyword  1  is entered as a search request. The results of search performed under these conditions are displayed. 
   Through the search system interface  20  from which the user transfers, the user selects and clicks a search system transfer button  2031  associated with a transfer-destination search system interface. Consequently, the user transfers from one search system to another search system. At this time, the results of search displayed through the search system interface  20  are taken over to the transfer-destination search system interface, and displayed in a screen image representing the search system interface. Furthermore, when the transfer-destination search system interface has a summary displaying feature or the like, a summary is created and displayed as if the search system interface searched documents. 
   For example, assume that the search system transfer button  2031  shown in  FIG. 3  is a transfer button allowing a user to transfer to the search system including the interface represented by the screen image shown in  FIG. 4 . When the button is clicked, the results of search corresponding to the results of search displayed by the search system as shown in  FIG. 3  are displayed by the transfer-destination search system as shown in  FIG. 4 . In this example, the search system including the interface represented by the screen image shown in  FIG. 4  has a summary displaying means. Therefore, the results of search are summarized and displayed by a summarizing means. 
   Next, how a user transfers one search system to another will be described by taking the above example. When a user clicks the search system transfer button  2031 , transfer is started. First, a document identifier reading means  2041  ( FIG. 6 ) included in a search takeover data producing means  204  is used to read a database name that is an object of search, and a list of identifiers of documents, which are the results of search, from the results-of-search displaying means. The read database name and identifiers of documents that are the results of search are converted into an associated database name employed in the transfer-destination search system, and associated document identifiers employed therein. In order to convert the read database name and document identifiers into the associated database name and document identifiers, a document identifier correspondence querying means  2042  passes the database name employed in the transfer-destination search system and the document identifiers employed therein to a document identifier associating means  402  included in the search system server. When the document identifier associating means  402  receives the associated name and identifiers, an interface is attained. Thus, search takeover data is produced to specify the associated database name and document identifiers that are employed in the transfer-destination search system. 
   A document identifier correspondence table  404  lists identifiers of articles recorded in document database  2  in association with identifiers of articles recorded in document database  1 . The document identifier associating means  402  included in the search system server references the document identifier correspondence table  404  using the received transfer-destination system name, database name, and document identifier. Consequently, the document identifier associating means  402  retrieves the associated name of document database  2  and the associated identifiers of the articles on documents recorded in the document database  2 . 
   The identifiers of documents that are the results of search can be readily collected from data held in the results-of-search displaying means  202 . 
   Incidentally, the document identifier correspondence table may be included in the transfer destination. In this case, identifiers employed in the document database  1  are specified in search takeover data. A search takeover data reading means included in the search system interface B is used to convert the document identifiers. Intermediate identifiers independent of a document database may be adopted as the document identifiers. Using the intermediate identifiers, the search takeover data can be readily produced. In this case, the correspondence table must be included in a system having a document database in which identifiers different from the intermediate identifiers are employed. In a special case where document identifiers are used in common among all systems or the document identifier correspondence table is not needed for association, the document identifier correspondence table may be excluded. 
   Incidentally, when a database can be identified from document identifiers, a database name may be excluded from search takeover data. 
   When a user can transfer from one interface, like the interface shown in  FIG. 3 , to any of a plurality of different interfaces, the format of a search takeover table or a procedure of calling a transfer-destination interface is different from transfer destination to transfer destination. An action to be performed according to the search takeover data producing means must therefore be changed based on a transfer destination. Specifically, actions to be performed according to a document identifier correspondence querying means  2042  and a search takeover data writing means  2043  must be changed. 
   The server of each transfer destination and a procedure of activating the server must be able to be identified using the search system transfer instructing means  203 . Moreover, data produced according to the search takeover data producing means must be passed to a transfer-destination system according to an appropriate procedure designated using the search system transfer instructing means  203 . The information required is described while being directly associated with the transfer instruction buttons  2031  and  2032 . A user selects either of the buttons so as to designate appropriate information and a processing means for performing successive processing. 
   Another procedure for installing a transfer-destination interface is such that transferring procedures are described separately and a correspondence table listing the descriptions of transferring procedures in association with transfer destinations is created. When a transfer instruction button is clicked, an associated description of a transferring procedure and an associated transfer destination are retrieved from the correspondence table, and interpreted. Thus, this procedure using a common means independently of a transfer destination may be adopted. 
   Using the document identifier correspondence querying means  2042 , associated identifiers must be varied depending on a transfer destination. Therefore, first, a server-vs.-database correspondence table  205  is referenced ( FIG. 2 ). Consequently, if a transfer destination is server B, an associated database is document database  2 . If a transfer destination is server C, an associated database is document database  3 . Thus, a database included in a transfer destination can be identified. A transfer-destination server name and a database name are designated in order to call a document identifier associating means included in server A. Thus, document identifiers are correctly converted into document identifiers employed in a database included in a transfer-destination server. 
   Likewise, using the search takeover data writing means  2043 , a format in which appropriate data is written must be selected according to a transfer destination. In this example, writing means  20432  and  20433  are dedicated in advanced to transfer destinations B and C respectively. A writing means  20431  is used to select either of the writing means  20432  and  20433  according to a transfer destination. Thus, writing actions are changed. 
   Incidentally, a common means may be used to define writing actions, interpret them, and execute any of them. Thus, action definitions may be changed in order to perform a different action. Eventually, a transfer destination may be installed. Furthermore, if the structure of takeover data is used in common, it is unnecessary to vary a writing format depending on a transfer destination. A single writing means should merely be adopted. 
   When the search system interface B is activated, if search takeover data is received through the search system interface ( FIG. 5 ), the search takeover data is passed to the search takeover data reading means  304 . Article identifiers are then retrieved from the search takeover data passed to the search takeover data reading means  304 , and converted into identifiers of the same format as the results of search provided by the searching means. The resultant identifiers are passed to the search system server B  50 . The search system server B does not use a searching means but regards the received list of article identifiers as the results of search and performs succeeding actions normally. In other words, the results of search are passed to the summarizing means  502 . A summary is then created. Finally, the results of search and summary are passed to the search system interface B  30 . The results-of-search displaying means  302  and summary displaying means  303  are used to display the results of search and summary respectively. Thus, transferring from one search system to another is completed. 
     FIG. 9  shows a search takeover record table  405  that is managed by the search system server A. In this example, the number of times by which the document database  1  is searched, and the number of times by which the results of search performed on the document database  1  are taken over in order to transfer from the search system interface A to the search system interface B that includes the document database  2  are counted and recorded in the table  405 . The former number of times is recorded in association with a row DB 1  and a column DB 1 , and the latter number of times is recorded in association with the row DB 1  and a column DB 2 . 
   In the present embodiment, the document identifier correspondence table included in the search system server A is used to convert identifiers specified in search takeover data. Therefore, the search system server A monitors a request issued through the search system interface A so as to learn what action is performed through the search system interface A performs. Specifically, if normal search is performed through the search system interface A, a search request is issued to the searching means  401 . If the search system transfer button  2031  included in the search system interface A is clicked in order to transfer the search system to another, since document identifiers are converted, a query about a database name and correspondence of document identifiers is issued. If the search request is issued, the value representing the number of times by which the document database  1  is searched is incremented by one. If the query is issued, the value representing the number of times by which the search system interface is transferred from the interface A to the interface B is incremented by one. 
   In the above example, the takeover identifier correspondence table is stored in the server A, the number of times by which transfer is made can be counted according to the foregoing method. If the identifier correspondence table is stored in a search system server of a transfer destination or if the identifier correspondence table is unnecessary, a query about conversion of identifiers is not issued. The foregoing method cannot therefore be adopted. In this case, through the search system interfaces, the search system servers are notified of the fact that one search system has been transferred to the other search system. 
   The search system server B may also count the aforesaid numbers of times according to the same method. When the numbers of times counted by the search system server A and the numbers of times counted by the search system server B are integrated with each other, more detailed information can be obtained. 
   By utilizing information concerning transferring from one search system to another which is acquired as mentioned above, user&#39;s likes concerning a search system can be learned. This may contribute to improvement of services. 
     FIG. 10 ,  FIG. 11 , and  FIG. 12  are concerned with a case where the present invention is implemented in a search service that is rendered using a system in which a summary of the results of search can be displayed through a search system interface included in a transfer destination. In this case where a search service is rendered, a search system interface A  70  shown in  FIG. 10  is included in a transfer source. The search system interface A is so simple that titles of documents that are the results of search are displayed and a user is prompted to select any of the titles so as to browse the text of the selected document. 
   When a button  701  Interface B included in the search system interface A  70  shown in  FIG. 10  is clicked, a search system interface B  80  shown in  FIG. 11  is activated. 
   Referring to  FIG. 11 , ten articles searched through the search system interface A  70  shown in  FIG. 10  are taken over to the search system interface B and displayed in the left half  801  of a screen image representing the interface B. Through the search system interface B, a summary of the ten articles is created and displayed in the right half  802  of the screen image representing the search system interface B. In this search service, the search system interface B shown in  FIG. 11  is activated while taking over the results of search from the transfer-source search system interface A  70 . In this state, the original features of the search system interface B  80  can be used. For example, three words “cloning,” “sapiens,” and “homo”( 901 ) may be selected from the summary, and a check mark ( 902 ) may be, as shown in FIG.  12 , assigned to the titles of documents containing the words. 
     FIG. 10  and  FIG. 13  are concerned with a case where the present invention is implemented in a search service that is rendered using a system in which through a search system interface included in a transfer source, the results of search are clustered and displayed hierarchically. 
   The search system interface A  70  shown in  FIG. 10  is included in a transfer source. The search system interface A is so simple that titles of documents that are the results of search are displayed through the search system interface A, and a user is prompted to select any of the titles so as to browse the text of the selected document. 
   When a button  702  Interface C included in the search system interface A  70  shown in  FIG. 10  is clicked, a search system interface C  100  shown in  FIG. 13  is activated. 
   Referring to  FIG. 13 , ten articles searched through the search interface A  70  shown in  FIG. 10  are clustered, and the hierarchical structure of the clustered articles is displayed in the left half  101  of a screen image representing the search system interface C. In this example, a cluster labeled “Gene” is selected ( 103 ). Accordingly, four out of the ten articles taken over, which belong to the cluster, are displayed in the right half  102  of the screen image representing the search system interface C. 
   As mentioned above, the present invention can be adapted to a case where all articles are not always displayed by a transfer destination or a successor. 
     FIG. 14  shows an example of an operation environment in which a search system server A and a search system server B share the same document database. In this case, the search system server A and search system server B share a document database  1043  accommodated by a network  10 . Since the document database is the same between the servers A and B, document identifiers are used in common. Therefore, a document identifier associating means N 1402  merely instructs the document identifier correspondence querying means ( 2042  in  FIG. 6 ) to convert nothing. Furthermore, the document identifier associating means N 1402  may be excluded. In this case, correction must be performed in order to correctly count the number of times by which search is taken over. The correction can be readily achieved supposing every time a user transfers one search system to another, the document identifier correspondence querying means  2042  notifies the search system server A of the fact. 
   A user displays the results of search performed by a certain search system using another search system whose features are different from those of the search system. Consequently, the user can review the same results of search from a different viewpoint. Eventually, the user can acquire valuable information that cannot be provided by a single search system, and have an in-depth understanding of the results of search. 
   The foregoing invention has been described in terms of preferred embodiments. However, those skilled, in the art will recognize that many variations of such embodiments exist. Such variations are intended to be within the scope of the present invention and the appended claims.