Personalization of Web Search Results Using Term, Category, and Link-Based User Profiles

Abstract

A system and method for creating a user profile and for using the user profile to order search results returned by a search engine. The user profile is based on search queries submitted by a user, the user's specific interaction with the documents identified by the search engine and personal information provided by the user. Terms for the user profile may be selected from the documents accessed by the user by performing paragraph sampling or context analysis. Generic scores associated with the search results are modulated by the user profile to measure their relevance to a user's preference and interest. The search results are re-ordered accordingly so that the most relevant results appear on the top of the list. User profiles can be created and/or stored on the client side or server side of a client-server network environment.

1 . A computer-implemented method of personalizing search results of a search engine, comprising:
 at a search engine system having a one or more processors and memory storing programs executed by the one or more processors:   accessing a user profile for a user, wherein content of the user profile is generated from user information that includes information derived from anchor text contained in documents that link to documents accessed by the user;   receiving a search query from the user;   identifying a set of search result documents that match the search query;   assigning a generic score to each document of at least a subset of the set of search result documents;   assigning a personalized score to each document of the subset of search result documents in accordance with the generic score assigned to the document and the user profile;   ranking the subset of search result documents according to their respective personalized scores;   providing the ranked subset of search result documents to a client system associated with the user; and   updating the user profile based on a document selected by the user from the ranked subset of search result documents.   
   
   
       2 . The method of  claim 1 , wherein the user information is derived from a first set of documents that includes: documents identified by search results from the search engine, documents accessed by the user, documents linked to the documents identified by search results from the search engine, and documents linked to the documents accessed by the user. 
   
   
       3 . The method of  claim 1 , including updating the user profile by:
 updating a term-based profile of the user profile by identifying a set of terms from a document in the first set of documents, and adding information about the identified set of terms to the term-based profile.   
   
   
       4 . The method of  claim 3 , wherein a term in the term-based profile is an expression comprising at least one word and a weight. 
   
   
       5 . The method of  claim 4 , wherein the weight is a weight associated with occurrences of the term in the first set of documents. 
   
   
       6 . The method of  claim 4 , wherein the weight of a term depends at least partially on the term's term frequency and inverse document frequency in said first set of documents. 
   
   
       7 . The method of  claim 1 , wherein the updating includes analyzing links within a document in the first set of documents and adding information derived from the analyzed links to the user profile. 
   
   
       8 . The method of  claim 7 , wherein the information derived from the analyzed links that is added to the user profile is added to a link-based profile and includes information about URLs or portions of URLs. 
   
   
       9 . The method of  claim 8 , wherein the link-based profile of the user profile comprises:
 a plurality of URLs and a weight associated with each URL, wherein the weight is based on one or more factors selected from the group consisting of frequency with which the user visits the URL, time the user has spent viewing a document associated with the URL and quantity of the user's scrolling activity at the document; and   a plurality of hosts and a weight associated with each host, wherein the weight is based on frequency of the user's visits to the host.   
   
   
       10 . The method of  claim 9 , wherein the URLs further include URLs that have not been visited by the user, but are related to the URLs that have been visited by the user and the weight of an unvisited URL depends on its distance to at least one related URLs that have been visited. 
   
   
       11 . The method of  claim 1 , wherein the updating includes updating a category-based profile of the user profile by classifying a document in the first set of documents into a plurality of categories, and adding information about the plurality of categories to the category-based profile. 
   
   
       12 . The method of  claim 11 , wherein a category in the category-based profile characterizes at least one aspect of documents in the category and the category is associated with a weight indicative of the category's importance relative to other categories. 
   
   
       13 . The method of  claim 12 , wherein the at least one aspect of the documents in the category is selected from the group consisting of: document format, document type, document topic and document origin. 
   
   
       14 . A computer-implemented method of personalizing search results of a search engine, comprising:
 creating a plurality of user profiles for a plurality of users, each user profile including at least a user's identification number and information derived from documents visited by the user, including information derived from anchor text contained in documents that link to the documents visited by the user;   receiving a search query from a user of the plurality of users, the search query including at least one query term and the user's identification number;   retrieving a user profile that matches the user's identification number;   generating a personalized query strategy from the search query and the user profile;   selecting a personalized set of documents from the Internet according to the personalized query strategy, each document having a generic ranking score based at least in part on the relevance of the document to the search query;   assigning to each document in the set a personalized ranking score based at least in part on the user profile and the document's generic ranking score;   ranking the set of documents according to their generic and personalized ranking scores;   providing the ranked set of search result documents to a client system associated with the user; and   updating the user profile of the user based on a document selected by the user from the set of search result documents.   
   
   
       15 . The method of  claim 14 , wherein creating a user's user profile further comprises:
 creating a term-based profile by extracting a set of terms from documents visited by the user and associating a weight with each extracted term; and   creating a category-based profile by determining a plurality of categories associated with documents visited by the user and associating a weight with each determined category.   
   
   
       16 . The method of  claim 14 , wherein creating a user's user profile further comprises:
 creating a link-based profile by analyzing links in documents visited by the user and associating weights with the link.   
   
   
       17 . The method of  claim 14 , wherein the user profile for a particular user includes demographic and geographic information provided by the user. 
   
   
       18 . The method of  claim 14 , wherein the ranked set of documents comprises two subsets of documents, one subset of documents ordered by their generic ranking scores and the other subset of documents ordered by personalized ranking scores. 
   
   
       19 . A search engine system, comprising:
 one or more central processing units for executing programs;   an interface for receiving information; and   a search engine module executable by the one or more central processing units, the module comprising:
 instructions for accessing a user profile for a user, wherein content of the user profile is generated from user information that includes information derived from anchor text contained in documents that link to documents accessed by the user; 
 instructions for receiving a search query from a user; 
 instructions for identifying a set of search result documents that match the search query; 
 instructions for assigning a generic score to each document of at least a plurality of the search result documents; 
 instructions for assigning personalized scores to each document of the plurality of search result documents in accordance with the generic score assigned to the document and the user's user profile; 
 instructions for ranking at least the plurality of the search result documents according to personalized scores; 
 instructions for providing the ranked set of search result documents to a client system associated with the user; and 
 instructions for updating the user profile based on a document selected by the user from the set of search result documents. 
   
   
   
       20 . The system of  claim 19 , wherein the user information is derived from a first set of documents that includes: documents identified by search results from the search engine, documents accessed by the user, documents linked to the documents identified by search results from the search engine, and documents linked to the documents accessed by the user. 
   
   
       21 . The system of  claim 19 , wherein the information derived from the analyzed links that is added to the user profile is added to a link-based profile and includes information about URLs or portions of URLs. 
   
   
       22 . The system of  claim 21 , wherein the link-based profile comprises:
 a plurality of URLs and a weight associated with each URL, wherein the weight is based on one or more factors selected from the group consisting of frequency with which the user visits the URL, time the user has spent viewing a document associated with the URL and quantity of the user's scrolling activity at the document; and   a plurality of hosts and a weight associated with each host, wherein the weight is based on frequency of the user's visits to the host.   
   
   
       23 . The system of  claim 22 , wherein the URLs further include URLs that have not been visited by the user, but are related to the URLs that have been visited by the user and the weight of an unvisited URL depends on its distance to at least one related URLs that have been visited. 
   
   
       24 . The system of  claim 19 , further including:
 instructions for updating a term-based profile by identifying a set of terms from a document in the set of documents, and adding information about the identified set of terms to the term-based profile; and   instructions for updating a category-based profile by classifying the document into a plurality of categories, and adding information about the plurality of categories to the category-based profile.   
   
   
       25 . The system of  claim 24 , wherein a term in the term-based profile is an expression comprising at least one word and a weight. 
   
   
       26 . The system of  claim 25 , wherein the weight is a weight associated with occurrences of the term in the set of documents. 
   
   
       27 . The system of  claim 25 , wherein the weight of a term depends at least partially on the term's term frequency and inverse document frequency in said set of documents. 
   
   
       28 . A computer readable storage medium storing one or more programs for execution by one or more processors, the one or more programs comprising:
 instructions for accessing a user profile for a user, wherein content of the user profile is generated from user information that includes information derived from anchor text contained in documents that link to documents accessed by the user;   instructions for receiving a search query from a user;   instructions for identifying a set of search result documents that match the search query;   instructions for assigning a generic score to each document of at least a plurality of the search result documents;   instructions for assigning personalized scores to each document of the plurality of search result documents in accordance with the generic score assigned to the document and the user's user profile;   instructions for ranking at least the plurality of the search result documents according to their personalized scores;   instructions for providing the ranked set of search result documents to a client system associated with the user; and   instructions for updating the user profile based on a document selected by the user from the set of search result documents.   
   
   
       29 . A computer-implemented method of personalizing search results of a search engine, comprising:
 at a search engine system having a one or more processors and memory storing programs executed by the one or more processors:   identifying a set of documents accessed by a user;   generating a user profile for the user that includes terms selected by sampling the identified set of documents, wherein sampling a document includes:
 excluding a set of predefined terms; 
 excluding paragraphs whose lengths are less than a predefined minimum length; and 
 limiting the number of terms selected from each paragraph to a predefined maximum number; 
   receiving a search query from the user;   identifying a set of search result documents that match the search query;   assigning a generic score to each document of at least a subset of the set of search result documents;   assigning a personalized score to each document of the subset of search result documents in accordance with the generic score assigned to the document and the user profile;   ranking the subset of search result documents according to their respective personalized scores;   providing the ranked subset of search result documents to a client system associated with the user; and   updating the user profile based on a document selected by the user from the ranked subset of search result documents.   
   
   
       30 . A computer-implemented method of personalizing search results of a search engine, comprising:
 at a search engine system having a one or more processors and memory storing programs executed by the one or more processors:   identifying a plurality of context patterns from a predefined set of documents, wherein each respective context pattern comprises a respective variable term and one or more respective fixed terms, and the respective variable term together with the respective fixed terms are in an identified ordered sequence;   generating a user profile for a user, wherein content of the user profile includes terms identified by applying the plurality of context patterns to documents accessed by the user;   receiving a search query from the user;   identifying a set of search result documents that match the search query;   assigning a generic score to each document of at least a subset of the set of search result documents;   assigning a personalized score to each document of the subset of search result documents in accordance with the generic score assigned to the document and the user profile;   ranking the subset of search result documents according to their respective personalized scores;   providing the ranked subset of search result documents to a client system associated with the user; and   updating the user profile based on a document selected by the user from the ranked subset of search result documents.