Related entities

Abstract

Methods, systems, and apparatus, including computer programs encoded on computer storage media, for identifying entities that are related to an entity to which a search query is directed. One of the methods includes receiving a search query, wherein the search query has been determined to relate to a first entity of a first entity type, and wherein one or more entities of a second entity type have a relationship with the first entity; receiving search results for the search query; determining that a count of search results identifying a resource containing a reference to the first entity satisfies a first threshold value; determining that a count of search results identifying a resource having the second entity type as a relevant entity type satisfies a second threshold value; and transmitting information identifying the one or more entities of the second entity type as part of the response to the search query.

What is claimed is: 
     
         1 - 20 . (canceled) 
     
     
         21 . A method performed by one or more computers, the method comprising:
 obtaining data identifying a first entity of a first entity type;   identifying a plurality of second entities of the first entity type that are related to the first entity;   determining a respective ranking score for each of the second entities of the plurality of second entities of the first entity type;   ordering the second entities of the first entity type according the ranking scores; and   generating a mapping from the first entity to each of the second entities based on the ordering of the second entities.   
     
     
         22 . The method of  claim 21 , further comprising:
 receiving a search query from a user device, wherein the search query has been determined to relate to the first entity of the first entity type;   in response to the search query, transmitting, to the user device, i) search results responsive to the search query and ii) information identifying an order of the second entities of the first entity type that matches the ordering.   
     
     
         23 . The method of  claim 22 , wherein the mapping defines the order of the second entities of the first entity type in response to received search queries that match the ordering. 
     
     
         24 . The method of  claim 21 , wherein identifying the plurality of second entities further comprises:
 identifying the plurality of second entities based on each of the second entities having a frequency of co-occurrence with the first entity in resources of an index of resources greater than a threshold.   
     
     
         25 . The method of  claim 24 , further comprising:
 determining, for each second entity, a co-occurrence score for the second entity based on the frequency of co-occurrence with the first entity in resources of the index of resources,   wherein the ranking score for each of the second entities is based on the respective co-occurrence score for the respective second entity.   
     
     
         26 . The method of  claim 21 , further comprising:
 determining, for each second entity, a subsequent query score for the second entity based a frequency of queries for the second entity after a submission of a query directed to the first entity,   wherein the ranking score for each of the second entities is based on the respective subsequent query score for the respective second entity.   
     
     
         27 . The method of  claim 24 , further comprising:
 determining, for each second entity, a co-occurrence score for the second entity based on the frequency of co-occurrence with the first entity in resources of an index of resources,   determining, for each second entity, a subsequent query score for the second entity based a frequency of queries for the second entity after a submission of a query directed to the first entity,   wherein the ranking score for each of the second entities is based on the respective co-occurrence score and the respective subsequent query score for the respective second entity.   
     
     
         28 . A system comprising one or more computers and one or more storage devices storing instructions that when executed by the one or more computers cause the one or more computers to perform operations comprising:
 obtaining data identifying a first entity of a first entity type;   identifying a plurality of second entities of the first entity type that are related to the first entity;   determining a respective ranking score for each of the second entities of the plurality of second entities of the first entity type;   ordering the second entities of the first entity type according the ranking scores; and   generating a mapping from the first entity to each of the second entities based on the ordering of the second entities.   
     
     
         29 . The system of  claim 28 , the operations further comprising:
 receiving a search query from a user device, wherein the search query has been determined to relate to the first entity of the first entity type;   in response to the search query, transmitting, to the user device, i) search results responsive to the search query and ii) information identifying an order of the second entities of the first entity type that matches the ordering.   
     
     
         30 . The system of  claim 29 , wherein the mapping defines the order of the second entities of the first entity type in response to received search queries that match the ordering. 
     
     
         31 . The system of  claim 28 , wherein identifying the plurality of second entities further comprises:
 identifying the plurality of second entities based on each of the second entities having a frequency of co-occurrence with the first entity in resources of an index of resources greater than a threshold.   
     
     
         32 . The system of  claim 31 , the operations further comprising:
 determining, for each second entity, a co-occurrence score for the second entity based on the frequency of co-occurrence with the first entity in resources of the index of resources,   wherein the ranking score for each of the second entities is based on the respective co-occurrence score for the respective second entity.   
     
     
         33 . The system of  claim 28 , the operations further comprising:
 determining, for each second entity, a subsequent query score for the second entity based a frequency of queries for the second entity after a submission of a query directed to the first entity,   wherein the ranking score for each of the second entities is based on the respective subsequent query score for the respective second entity.   
     
     
         34 . The system of  claim 31 , the operations further comprising:
 determining, for each second entity, a co-occurrence score for the second entity based on the frequency of co-occurrence with the first entity in resources of an index of resources,   determining, for each second entity, a subsequent query score for the second entity based a frequency of queries for the second entity after a submission of a query directed to the first entity,   wherein the ranking score for each of the second entities is based on the respective co-occurrence score and the respective subsequent query score for the respective second entity.   
     
     
         35 . One or more non-transitory computer storage media storing instructions that when executed by one or more computers cause the one or more computers to perform operations comprising:
 obtaining data identifying a first entity of a first entity type;   identifying a plurality of second entities of the first entity type that are related to the first entity;   determining a respective ranking score for each of the second entities of the plurality of second entities of the first entity type;   ordering the second entities of the first entity type according the ranking scores; and   generating a mapping from the first entity to each of the second entities based on the ordering of the second entities.   
     
     
         36 . The computer storage media of  claim 35 , the operations further comprising:
 receiving a search query from a user device, wherein the search query has been determined to relate to the first entity of the first entity type;   in response to the search query, transmitting, to the user device, i) search results responsive to the search query and ii) information identifying an order of the second entities of the first entity type that matches the ordering.   
     
     
         37 . The computer storage media of  claim 36 , wherein the mapping defines the order of the second entities of the first entity type in response to received search queries that match the ordering. 
     
     
         38 . The computer storage media of  claim 35 , wherein identifying the plurality of second entities further comprises:
 identifying the plurality of second entities based on each of the second entities having a frequency of co-occurrence with the first entity in resources of an index of resources greater than a threshold.   
     
     
         39 . The computer storage media of  claim 38 , the operations further comprising:
 determining, for each second entity, a co-occurrence score for the second entity based on the frequency of co-occurrence with the first entity in resources of the index of resources,   wherein the ranking score for each of the second entities is based on the respective co-occurrence score for the respective second entity.   
     
     
         40 . The computer storage media of  claim 35 , the operations further comprising:
 determining, for each second entity, a subsequent query score for the second entity based a frequency of queries for the second entity after a submission of a query directed to the first entity,   wherein the ranking score for each of the second entities is based on the respective subsequent query score for the respective second entity.