Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for providing knowledge panels with search results. In one aspect, a method includes receiving a query. Search results that are responsive to the query are obtained. A first set of factual entities referenced by the query are identified. A particular factual entity is selected from the first set. It is determined that a knowledge panel for the particular factual entity is to be provided with the search results based, at least in part, on content of the knowledge panel and characteristics of the search results. The knowledge panel can include at least one content item, for the selected factual entity, received from a first resource and at least one content item, for the selected factual entity, received from a second resource different than the first resource. The knowledge panel is provided.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for providing knowledge panels with search results. In one aspect, a method includes receiving a query. Search results that are responsive to the received query are obtained. A first set of factual entities referenced by the received query are identified. A particular factual entity is selected from the first set. It is determined that a knowledge panel for the particular factual entity is to be provided with the search results based, at least in part, on content of the knowledge panel and characteristics of the search results. The knowledge panel can include at least one content item, for the selected factual entity, received from a first resource and at least one content item, for the selected factual entity, received from a second resource different than the first resource. The knowledge panel is provided.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for query analysis. Queries are identified in query data, and an entity-descriptive portion and a suffix are determined in each query. Query counts are determined for a number of times that the respective queries occur in the query data. Based on the query counts, an entity-level count is estimated, which represents a number of query submissions that include the particular suffix and are considered to refer to a first entity. The entity is determined to be a particular type of entity. A type-level count is determined, which represents a number of query submissions that include the first suffix and are estimated to refer to entities of the particular type of entity. A score is assigned to the particular suffix based on the entity-level count and the type-level count.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for providing knowledge panels. In one aspect, a method includes determining an entity that is referenced by a received search query. Content items relevant to the entity are identified. A set of knowledge modules is selected for presentation in a knowledge panel for the entity. The knowledge panel can be a portion of a search results page in which knowledge modules are presented. Data that causes the knowledge modules to be presented in the knowledge panel is provided to a user device.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for providing knowledge panels. In one aspect, a method includes determining an entity that is referenced by a received search query. Content items relevant to the entity are identified. A set of knowledge modules is selected for presentation in a knowledge panel for the entity. The knowledge panel can be a portion of a search results page in which knowledge modules are presented. Data that causes the knowledge modules to be presented in the knowledge panel is provided to a user device.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for providing knowledge panels. In one aspect, a method includes determining an entity that is referenced by a received search query. Content items relevant to the entity are identified. A set of knowledge modules is selected for presentation in a knowledge panel for the entity. The knowledge panel can be a portion of a search results page in which knowledge modules are presented. Data that causes the knowledge modules to be presented in the knowledge panel is provided to a user device.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for associating each of a plurality of different terms to documents that contain the term to create first associations; associating each of the associated documents to one or more queries to create second associations, wherein search results for each of the queries include a reference to the associated document; determining a particular query and a particular term are associated with a same document based on the first and second associations; in response to the determination, creating a mapping between the particular query and the particular term when both are associated with the same document; and selecting a respective answer from a plurality of mapped terms for each the mapped queries, wherein the respective answer is selected based on a count the respective answer occurs in documents contained in search results for the mapped queries.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for providing knowledge panels with search results. In one aspect, a method includes receiving a query. Search results that are responsive to the received query are obtained. A first set of factual entities referenced by the received query are identified. A particular factual entity is selected from the first set. It is determined that a knowledge panel for the particular factual entity is to be provided with the search results based, at least in part, on content of the knowledge panel and characteristics of the search results. The knowledge panel can include at least one content item, for the selected factual entity, received from a first resource and at least one content item, for the selected factual entity, received from a second resource different than the first resource. The knowledge panel is provided.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for query analysis. Queries are identified in query data, and an entity-descriptive portion and a suffix are determined in each query. Query counts are determined for a number of times that the respective queries occur in the query data. Based on the query counts, an entity-level count is estimated, which represents a number of query submissions that include the particular suffix and are considered to refer to a first entity. The entity is determined to be a particular type of entity. A type-level count is determined, which represents a number of query submissions that include the first suffix and are estimated to refer to entities of the particular type of entity. A score is assigned to the particular suffix based on the entity-level count and the type-level count.

Abstract: Methods, systems, and apparatus, including computer program products, for ranking search results of a search query using corpus search statistics. In one aspect, a method includes determining a first relevance of a first corpus to a search query, determining a second relevance of a second corpus to the search query, determining a measure of relative relevance of the first corpus and the second corpus to the search query, and providing the measure of relative relevance to a ranking engine for ranking of search results for a new search corresponding to the search query.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for information retrieval. In one aspect, a method includes receiving a fact query; determining an expected type of answer to the fact query; identifying search results responsive to the fact query; identifying phrases from the resources corresponding to the search results that correspond to a form of the expected type; determining a score for each of the identified phrases; and presenting an answer to the fact query using the scores.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for providing knowledge panels. In one aspect, a method includes determining an entity that is referenced by a received search query. Content items relevant to the entity are identified. A set of knowledge modules is selected for presentation in a knowledge panel for the entity. The knowledge panel can be a portion of a search results page in which knowledge modules are presented. Data that causes the knowledge modules to be presented in the knowledge panel is provided to a user device.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for machine learning. In one aspect, a method includes receiving a collection of facts, each fact represented as an entity-attribute-value tuple; identifying expected values for one or more individual attributes, where the identifying expected values includes, for each particular attribute: identifying facts having the attribute, calculating a value score for facts of the collection of facts having the particular attribute for each particular value, calculating a global score for all facts of the collection having the attribute, and comparing the value score to the global score such that a value is identified as an expected value if the comparison satisfies a specified threshold.

Abstract: Methods, systems, and apparatus, including computer program products, for ranking search results of a search query using corpus search statistics. In one aspect, a method includes determining a first relevance of a first corpus to a search query, determining a second relevance of a second corpus to the search query, determining a measure of relative relevance of the first corpus and the second corpus to the search query, and providing the measure of relative relevance to a ranking engine for ranking of search results for a new search corresponding to the search query.