A computer program and system for navigating through electronic documents

FIELD OF THE INVENTION

The invention relates to the field of navigating through a set of electronic documents. More specifically, the invention relates to the field of navigating through a set of electronic documents using links.

BACKGROUND OF THE INVENTION

Many existing systems have been developed to enable a user to navigate through a set of documents, in order to find one or more of those documents which are particularly relevant to that user's needs. For example, HyperText Markup Language (HTML) permits web page designers to construct a web page that includes one or more "hyperlinks" (also sometimes referred to as "hot links" or simply "links"), which allow a user to "click- through" from a first web page to other, different web pages or other sections of the same web page. Each hyperlink is associated with a portion of the web page, which is typically displayed in some predetermined fashion.

While hyperlinks do provide users with a limited number of links to other web pages, their associations to the other web pages are fixed and designated according to the preferences of the webmaster. Moreover, because the number of hyperlinks within a given web page is generally limited, when a user desires to obtain information regarding a term, phrase or paragraph that is not associated with a hyperlink, the user must employ another technique. One such existing technique is by copying the term and submitting it to a search engine.

Search engines, such as the search engine of Google™, enable a user to search the World Wide Web ("Web") for documents related to a search query provided by the user. Typical search engines operate through a web browser interface. Search engines generally require the user to enter a search query, which is then compared with entries in an "index" describing the occurrence of terms in a set of documents that have been previously

analysed, for example by a program referred to sometimes as a "web spider" .

Google also provides a tool bar for a web browser having an AutoLink button. If a web page is loaded, clicking on the AutoLink button traces certain terms on the webpage having a predefined format, such as addresses, ISBN numbers and vehicle identification numbers. The terms are subsequently converted to hyperlinks to further information.

US 6,862,710 discloses a system for internet navigation using soft hyperlinks, in connection with an information retrieval system with which it may be used. The navigation tool provides freedom to move through a collection of electronic documents independent of any hyperlink which has been inserted within an HTML page. A user can click on any term in a document page, not only those that are hyperlinked. When a user clicks on an initial word within the document, a search engine is employed in the background to retrieve a list of related terms. These returned terms have the highest degree of correlation with the initial search term in a lexical knowledge base that the search engine constructs automatically.

SUMMARY OF THE INVENTION

It is an object of the invention to provide an improved computer program and system for navigating through a set of electronic documents.

To this end, the invention provides a computer program for navigating through a set of electronic documents capable of running at a client communication unit. The program comprises computer-readable instructions for performing the tasks of: - retrieving an electronic document containing one or more terms from a document source;

- retrieving a link status for said electronic document from a link database, said link status being indicative of whether one or more of said terms has been marked as a link to fur- ther information before said retrieval of said electronic document ;

- displaying said electronic document, wherein terms of said document are marked in accordance with said link status, and

- selecting said marked terms.

The invention also provides a link server for use in a system for navigating through a set of electronic documents comprising a link database with a link status for one or more electronic documents indicative of the presence of one or more terms in said documents that are linked to further information. The link server is capable of communicating with at least one client communication unit and arranged to:

- receive a request from said client communication unit for the link status of an electronic document,

- determine said link status associated with said electronic document from said link database, and

- send said link status to said client communication unit.

By keeping a database with a link status for each elec- tronic document, hyperlinks to further information created at a first client communication unit can be transferred to further client communication units retrieving this electronic document as the link status is retrieved independent of the electronic document. Accordingly, client-side created hyperlinks to further information are available to others without requiring authorisation or participation of webmasters or other people responsible for the electronic document. Consequently, the flexibility of navigation through electronic documents is enhanced.

It should be appreciated that the computer program ac- cording to the invention may be a browser with the specified functionality, a standard browser with a plug-in or extension adding this functionality to the standard browser as well as any other computer program suitable to perform the tasks. Further, it should be noted that execution of the various tasks may be distributed over several programs or hardware units that may e.g. be connected by a communication network.

It should also be appreciated that the further information may e.g. either be a further electronic document or a list of further electronic documents from which a preferred further electronic document may be selected. This list may e.g. have been generated by one or more search engines retrieving relevant further electronic documents associated with the marked term.

Consequently, navigation through a set of electronic documents is enabled.

The embodiments of the invention as defined in claims 2 and 16 provides for the advantage that transferable links to further information can be created at the client communication unit. Consequently, substantially any term of the electronic document can be marked as a link to further information associated with that term and the user is no longer bound to the preferences made by the master of the electronic document, i.e. the links generated for this document by the webmaster. Further, copying and pasting of the term to a search engine with subsequent activation of the search engine is avoided and replaced by simply marking the term and selecting (e.g. by clicking with a mouse cursor on the marked term) the term to retrieve the fur- ther information.

The embodiments of the invention as defined in claims 3 and 19 provide the advantage that a user is informed on the relevance of the further information by previous users having e.g. rated and/or commented on the further information. Further, by using the rating information field, the relevance of the further information can be determined and the further information can be presented to the user on the basis of its relevance.

The embodiment of the invention as defined in claim 5 allows displaying the marked terms without modifying the source code, e.g. the HTML code of a webpage, of the electronic document .

The embodiment of the invention as defined in claim 6 is advantageous as XML code is a user definable code and is particularly suitable for transferring short messages. The embodiment of the invention as defined in claim 8 provides the advantage that a client communication unit and/or a user of a client communication unit can be identified and services rendered to the client communication unit and/or user can be individualized. Accordingly, transferability of marked terms as links to further information can be blocked, whereas for the individual client communication unit and/or user the terms may remain marked as links to further information.

For the embodiment allowing users to create transferable client-side created links, those owning or being responsible for electronic documents (e.g. webmasters) may have concerns on how their documents are displayed at communication units running the computer program of the invention. In the embodiment of the invention as defined in claim 9, these proprietors are presented with the opportunity to influence the transferability of terms marked as links in their electronic document to further client communication units. In the embodi- ment of the invention as defined in claim 10, the number of terms permitted to be transferred as marked terms to further client communication units may be influenced and even set to zero, if desired. Accordingly, abuse of the means to add links to an electronic document may be prevented or reduced. In the embodiment of the invention as defined in claim 11, people mastering electronic documents with e.g. a high refresh rate (e.g. news websites) may set a time interval wherein terms may be marked as a link to further information. Afterwards, terms can no longer be transferred as links, e.g. because the marking of terms is no longer registered at the link server after the expiry time. The embodiment of the invention as defined in claim 12 prohibits transferring of certain terms as a link by e.g. defining a blacklist. The embodiment of the invention as defined in claim 13 allows proprietors to define from which communica- tion units terms may be marked. In this latter embodiment, proprietors may in fact decide not to cooperate in transferring of client-side created links to other client communication units .

The embodiment of the invention as provided in claims 17 and 18 provides for a suitable way to obtain further information related to a marked and selected term in an electronic document .

The invention also provides a system for navigating through a set of electronic documents comprising a link server as described above.

Furthermore, the invention provides a computer program comprising software code portions for running at such a link server.

Still further, the invention provides a document server capable of providing access to one or more electronic documents by a client communication unit. The document server is for use in a system comprising a link server having a link database with a link status for one or more of said electronic documents indicative of the presence of one or more terms in said documents linked to further information. The link server is arranged for communicating said link status to said client communication unit. At least one of the electronic documents in the document server comprises one or more instructions for displaying said electronic document and said terms on said client communication unit in accordance with said link status.

Proprietors of electronic documents are accordingly presented with the opportunity to influence the transferability of the client-side created links in the electronic document.

Finally, the invention provides an electronic document comprising one or more instructions for displaying said electronic document and the terms on said client communication unit in accordance with the link status of the document. Further embodiments and advantages thereof will be described in the detailed description of the drawings.

The invention will be further illustrated with reference to the attached drawings, which schematically show a preferred embodiment according to the invention. It will be un- derstood that the invention is not in any way restricted to this specific and preferred embodiment.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings : FIG. 1 shows a schematic illustration of a system for navigating through a set of electronic documents according to an embodiment of the invention;

FIG. 2 schematically illustrates communication flows within the system of FIG. 1, and FIGS. 3A and 3B respectively show a schematic capture of a portion of a web page having a term marked as a link and an overlay with further information displayed to a user after selection of said link

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a schematic illustration of a system 1 for navigating through a set of electronic documents according to an embodiment of the invention. The system 1 comprises a client communication unit 2, a document server 3, a link server 4 and a search engine 5.

The client communication unit 2 may e.g. be a personal computer capable of establishing a connection over a network 6, such as the internet. However, it should be appreciated that the network may also be an internal network within e.g. a company, often referred to as intranet. Further it is noted that the network 6 may be a (partly) wireless network.

The client communication unit 2 may also be a portable computer or any other device capable of establishing a network connection with the document server 3 and link server 4. The client communication unit 2 has a display 7 for displaying electronic documents employing a browser 11, schematically illustrated in FIG. 2. The client communication unit 2 further has a memory

(not shown) for storing the computer program 10 according to the invention and a processor (not shown) for executing the computer program 10. Further, the client communication unit 2 or a user of the client communication unit 4 may identify himself, e.g. be an e-mail address or a unique code for client communication unit 2, at the link server 4. Validation of a user and/or client communication unit 2 may occur at the link server 4.

The document server 3 contains electronic documents D comprising one or more terms T, as illustrated in FIGS. 3A and 3B. The electronic documents D may e.g. be in HTML code or XML code or any other suitable code enabling the browser 11 of the client communication unit 2 to suitably display the electronic document D on the display 7.

The link server 4 has access to a link database 8 and is capable of communicating over the network 6 with at least one client communication unit 2. The link database 8 has a link status for one or more electronic documents D indicative of the presence of one or more terms T in said documents linked to fur-

ther information. The link server 4 runs a computer program to perform one or more of the tasks described below in further detail.

The search engine (s) 5 may perform a search for further information in response to an instruction of e.g. the link server 4 as will be described below in further detail. Preferably, more than one search engine is employed to retrieve the further information. Examples of search engines 5 include Google.com, Answers.com and WikiPedia.org. It should however be appreciated that other internet information sources may be used as well for retrieving the further information. An example of an other information source includes but is not limited to a dedicated database with links for particular terms. Furthermore, the user of the client communication unit 2 may indicate his pre- ferred source or sources of information, such as one or more preferred search engines.

The operation of the computer program 10 will next be described with reference to FIG. 2 and FIGS. 3A and 3B.

It should be appreciated that the computer program 10 may be a browser 11 with the specified functionality. Alternatively, a standard browser 11 with a plug-in or extension 12 adding this functionality to the standard browser may be used, such as FireFox, Internet Explorer or Netscape Navigator. However, any other computer program or application suitable to perform one or more of the tasks described next may be employed.

Furthermore, it should be noted that execution of one or more of the various tasks may be distributed over several programs or hardware units that may e.g. be connected by a communication network or internally in the client communication unit 2. Moreover, the computer program 10 may be run from a website for users that do not want to download and install the computer program on the client communication unit 2. The invention may also be embodied in an operating system, such as Windows or Linux. For clarification purposes only, FIG. 2 displays the situation of a computer program 10 having a standard web browser 11 for browsing HTML documents available over the internet 6 and a plug-in or extension 12 for performing the task according to

an embodiment of the invention. Although the electronic documents preferably are web pages, the electronic documents may include alternative documents such as Word documents etc or any other document containing text . Suppose a user of the client communication unit 2 is about to start browsing electronic documents available over the internet 6. He fills in the uniform resource locator (URL) of the electronic document D at the appropriate location in the web browser 11 and a http-request (step I) is sent over the internet 6. Simultaneously or subsequently, the web browser 11 informs the plug-in or extension 12 (step II) to retrieve the link status for the electronic document D from the link database 8 (steps III and IV) . The link status may e.g. be communicated to the client communication unit 2 as an XML message. Said XML mes- sage is generally a small message and available at the client communication unit 2 before the electronic document D is retrieved. On retrieval of the electronic document D from the document server 3 (step V) , the plug-in or extension 12 informs the browser 11 (step VI) which terms T of the document D have been previously marked as a link to further information. Preferably, the plug-in or extension only informs the terms T to be marked as a link in the electronic document D without modifying the HTML code of the electronic document D neither at the document server 3 nor at the client communication unit 2. The electronic document D is subsequently displayed on the display 7 of the client communication unit 2 such that terms T of said document are marked (e.g. highlighted or in some other predetermined fashion) in accordance with said link status retrieved from the link database 8. It should be noted that the sequence of the steps I -VI may vary as will be appreciated by the man skilled in the art. It is further noted that communication between the client communication unit 2 and the document server 3 may occur via a first network, whereas communication between the client communication unit 2 and the link server 4 occurs via a second network

(partly) different from the first network. This may be an advantage as the bandwidth requirements for transfer of the link status of an electronic document may be rather limited.

The user may subsequently select the marked items (if any) and navigate to the further information, as will be described next .

When the link status for the document D retrieved from the link database 8 indicates that one or more terms T have been marked previously as a link to further information, the electronic document displayed on the client communication unit 2 contains these marked terms. A marked term should be understood to include any kind of appearance of the term indicating the term as a link to further information, such as highlighted terms, bold terms, italic terms, underlined terms, terms in different colours, combinations of these measures or some other visual indication that the term is marked as a link to further information. In FIG. 3A, the previously marked term T (in this case "Vannevar Bush") is displayed at the client communication unit 2 as a bold, underlined term.

The marked term "Vannevar Bush" may then be selected, e.g. by clicking on said term with a mouse cursor, which generates a navigation request for further information from the client communication unit 2 to the link server 4. The link server 4 triggers the search engine (s) 5 to search for further information related to the term "Vannevar Bush" . The further information may subsequently be displayed in an overlay 0 at the client communication unit 2 as a list of further selectable electronic documents resulting from three search engines

5A,5B,5C, as shown in FIG. 3B. Furthermore, advertising messages ADl, AD2 , AD3 may appear in the overlay 0.

It should be appreciated that, preferably, each selection of a term generates a new request to the link server 4 and initiates a new search request to guarantee that the user of the client communication unit 2 is presented with up-to-date further information. The search request may involve a search for further information conducted by one or more search engines 5A, 5B, 5C or in an alternative information source, such as a dedicated link database with link(s) to further information, e.g. suggested by users, for a particular term.

When the link status retrieved from the link server 4 indicates that the retrieved electronic document does not con-

tain previously marked terms (or when a user of a client communication unit desires to mark further terms in an electronic document already containing other marked terms) , the computer program 10 preferably enables the user to mark one or more terms T of the electronic document D at the client communication unit 2 as a link to the further information. In principle, any term T of the document may be marked as a link. A term may comprise one or more words, symbols, numbers etc. Marking of a term T as a link to further information may be accomplished by a simple op- eration of e.g. the mouse. If such a term T is marked as a link to further information, the client communication unit 2 informs the link database by a link creation request to update the link status for the electronic document D accordingly. Further information relating to this marked term T is subsequently displayed on display 7 of the client communication unit 2 by selecting the marked term T (e.g. by clicking on this marked term by the mouse cursor) and e.g. the search engine (s) 5 deliver the further information, as described above. The further information comprises further selectable electronic documents available over the internet 6 constituting the set of electronic documents through which the user navigates .

By keeping the link database 8 with a link status for each electronic document D, links to further information created at a first client communication unit 2 may thus be transferred to further client communication units 2 retrieving this electronic document D. The terms marked at the first client communication unit 2 as a link to further information remain visible to a user of a further client communication unit if the computer program 10 of the invention also operates on this fur- ther client communication unit. Accordingly, client-side created links to further information created by one user are available to other users without requiring participation of webmasters or other people responsible for the electronic document D. The system and computer program of the invention may therefore also be described as a system for transferring client-side created links. Consequently, the flexibility of navigation through electronic documents is enhanced.

It should be appreciated that the electronic documents selected from the further information may be retrieved from a server other than the document server 3.

Preferably, the computer program 10 further allows us- ers to add information, such as rating information and/or comments, to the further information which user information is stored in the link database 8 with the URL of the electronic document and the terms marked as links to further information in this document. Accordingly, further users may profit from the user information (e.g. comments and rates) of previous users. In a particularly advantageous embodiment of the invention, the link server 4 is arranged to present the further information in accordance with a rating obtained from previous users. For example, if Vannevar Bush has a personal website, users previously having found this website may highly recommend this site and, consequently, the link server 4 provides as the further information the personal website of Vannevar Bush as the top most link to further users. Alternatively or in addition, the link to the personal website may be suggested by a user independent from the search engines in e.g. a dedicated link database. This suggestion may appear in the further information in a section of the overlay 0 separate from the further information generated by the search engines 5A,5B,5C.

Furthermore, the link server may count how many times a certain term T, marked as a link to a further electronic document, is selected and present the link to the document with the highest count on the top of the list of the further information. Accordingly, preferred links for each marked term may be established automatically. Preferably, the link server 4 allows identification of the client communication unit 2 or a user by e.g. a unique code of the computer program 10 or an e-mail address.

From the description above, it should be clear that the invention allows the creation of transferable links in elec- tronic documents without previous authorisation or participation of the proprietor of the electronic document. In fact, the proprietor of an electronic document may not even notice the creation of links in his document, since the electronic document

itself is not modified at the document server 3. Only users of the computer program 10 according to the invention will be able to display the marked terms T identified in the link status of the electronic document . Obviously, some proprietors may not appreciate the loss of control on the appearance of their documents at the client communication unit 2. Therefore, the invention allows for the inclusion of instructions for displaying the marked terms in the electronic document and the computer program 10 is arranged for processing these instructions and displaying the electronic document in accordance with these instructions.

The possibility of inserting instructions in the electronic document provides the proprietors of these documents with control on the use, in particular the transferability, of cli- ent-side creation of links in their documents. The instructions can be used to enhance or limit the possibility of marking terms as links and their transferability. The instruction (s) may e.g. be implemented in the electronic document as meta-tags in a HTML document . More specifically, the instructions for displaying the marked term(s) T in the electronic document D may comprise instructions for limiting the number of terms that may be marked in that document. As an example, the webmaster may prescribe that a maximum of three terms may be marked as a link to further information to balance the desire of users to create links in the document and the desire to maintain the carefully designed appearance of the document. If a further term T is marked in excess of the maximum number of markable terms T set in the electronic document, these marked terms are not transferable to other communication units 2. It should be noted that this does not necessarily imply that the link database does not register marking of the term. The terms T marked as links in excess of the set maximum number of markable terms may still be available for the user having marked these terms. The user may be warned that no further terms may be marked. Also, the marking of a previous term may be cancelled and the latest marking may create a link to the further information. The amount of markable terms T may be set to zero, infinite or any number in between.

Alternatively or in addition, the instructions in the electronic document D for displaying marked terms T may comprise an expiration time after which terms may no longer be marked as links to further information. Afterwards, terms T can no longer be transferred as links, e.g. because the marking of terms T is no longer registered at the link server after the expiry time. This option may e.g. be advantageous for dynamic electronic documents with a high refresh rate, such as news websites.

Alternatively or in addition, the instructions in the electronic document D for displaying marked terms T may comprise instructions for prohibiting one or more terms T to be transferred. These instructions prohibit transfering of certain marked terms as a link by e.g. defining a blacklist. Besides very common words as "and", "a", "by", "they" etc., proprietors of documents may also prohibit marking of other terms as they desire, such as e.g. a company name, a competitor's name or a trademark. It should be noted that the link server 4 may also employ one or more blacklists of terms that cannot be transferred as a link to further information. It should further be noted that, again, the user of a client communication unit 2 may still mark any term T as a link to further information; only the transferability of the marked term is prohibited.

Alternatively or in addition, the instructions in the electronic document D for displaying marked terms T may comprise instructions for which client communication units 2 which marked terms T may be displayed. This embodiment of the invention allows proprietors to define from which communication units 2 terms may be marked. In this latter embodiment, proprietors may in fact decide not to cooperate in transferring of client-side created links to other client communication units 2. The proprietor may e.g. decide that the terms marked from a certain client communication unit 2 are only visible for that communication unit 2.

The electronic documents may also comprise a webmaster tag to add electronic documents to the link database 8 or the document server 3. When signing up as a webmaster, a code is issued by the link server 4 that may be added to the electronic document. This code may be used as a tracker. The link server 4

may generate statistics for this document and track usage. Webmasters will be able to track electronic documents based on this code, add blacklisted words, track which terms T are marked most as a link to further information etc. Although the invention is described in a network environment, more specifically an internet environment employing servers adapted to communicate with a client communication unit over the internet, the invention may also be applied on smaller networks and even on a stand-alone computing device. In the lat- ter case, the computer has an internal document source, such as a memory for documents, and an internal database that traces the creation of links in the documents in the documents and stores these for subsequent use of the document .