Abstract: Content object tags at a content hosting service are used to classify stored content objects. Tags and clusters of tags (groups of one or more associated tags) can be recommended to a user of the content hosting service based on a user context, such as the browsing, viewing, uploading, or searching of content objects. Tags are scored based on content objects tagged with the tags in a targeted subset of content objects and a baseline subset of content objects, and based on the relevance of the content objects tagged with the tags. These tag scores can be weighted, and one or more tags can be selected for recommendation based on the weighted tag scores. Tag clusters can be selected for recommendation using a cluster hierarchy and determining whether a targeted subset of tags occur within a maximum number of tag clusters at a particular hierarchy level.

Abstract: Collections identifying associated content objects, such as user-defined collections, are stored. A request to display or play a seed content object is received. A plurality of seed collections are identified based on the seed object. A plurality of candidate content objects are identified based on the identified seed collections, for instance by identifying the content objects that are identified by the seed collections. Properties of the seed object are identified, such as the categorization of the seed object, or the tags associated with the seed object. The candidate objects are ranked based on the identified seed collections and the identified properties of the seed object, and a candidate object is selected for recommendation to the user based on the ranking. The ranking of candidate objects can also be determined based on the coherence of the seed collections and the centrality of the seed object to the seed collections.

Abstract: Collections identifying associated content objects, such as user-defined collections, are stored. A request to display or play a seed content object is received. A plurality of seed collections are identified based on the seed object. A plurality of candidate content objects are identified based on the identified seed collections, for instance by identifying the content objects that are identified by the seed collections. Properties of the seed object are identified, such as the categorization of the seed object, or the tags associated with the seed object. The candidate objects are ranked based on the identified seed collections and the identified properties of the seed object, and a candidate object is selected for recommendation to the user based on the ranking. The ranking of candidate objects can also be determined based on the coherence of the seed collections and the centrality of the seed object to the seed collections.

Abstract: Content object tags at a content hosting service are used to classify stored content objects. Tags and clusters of tags (groups of one or more associated tags) can be recommended to a user of the content hosting service based on a user context, such as the browsing, viewing, uploading, or searching of content objects. Tags are scored based on content objects tagged with the tags in a targeted subset of content objects and a baseline subset of content objects, and based on the relevance of the content objects tagged with the tags. These tag scores can be weighted, and one or more tags can be selected for recommendation based on the weighted tag scores. Tag clusters can be selected for recommendation using a cluster hierarchy and determining whether a targeted subset of tags occur within a maximum number of tag clusters at a particular hierarchy level.

Abstract: Content object tags at a content hosting service are used to classify stored content objects. Tags and clusters of tags (groups of one or more associated tags) can be recommended to a user of the content hosting service based on a user context, such as the browsing, viewing, uploading, or searching of content objects. Tags are scored based on content objects tagged with the tags in a targeted subset of content objects and a baseline subset of content objects, and based on the relevance of the content objects tagged with the tags. These tag scores can be weighted, and one or more tags can be selected for recommendation based on the weighted tag scores. Tag clusters can be selected for recommendation using a cluster hierarchy and determining whether a targeted subset of tags occur within a maximum number of tag clusters at a particular hierarchy level.