Abstract: Methods, systems, and apparatus, including computer programs encoded on computer storage media, for ranking search results. One of the methods includes identifying one or more sessions for a query and associating watch times of the respective resources watched in the sessions with the query. One or more watch time signals are calculated for a first resource and the query based on the watch times associated with the query. A first search result responsive to the query is obtained, wherein the first search result identifies the first resource and has an associated score S. A new score S? is calculated based on a least S and a watch time function, the watch time function being a function of the one or more watch time signals. The new score S? is provided to a process for ranking search results including the first search result.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for presenting related conversations. In one aspect, it is determined that a portion of a conversation thread includes an exchange of messages between fewer than a predetermined number of conversation participants. Based on determining that the portion of the conversation thread includes the exchange of messages between fewer than the predetermined number of conversation participants, a conversation view can be generated that that includes a flattened representation of the portion of the conversation thread.

Abstract: Methods, systems, and apparatus, including computer programs encoded on computer storage media, for ranking search results. One of the methods includes identifying one or more sessions for a query and associating watch times of the respective resources watched in the sessions with the query. One or more watch time signals are calculated for a first resource and the query based on the watch times associated with the query. A first search result responsive to the query is obtained, wherein the first search result identifies the first resource and has an associated score S. A new score S? is calculated based on a least S and a watch time function, the watch time function being a function of the one or more watch time signals. The new score S? is provided to a process for ranking search results including the first search result.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for presenting related conversations. In one aspect, it is determined that a portion of a conversation thread includes an exchange of messages between fewer than a predetermined number of conversation participants. Based on determining that the portion of the conversation thread includes the exchange of messages between fewer than the predetermined number of conversation participants, a conversation view can be generated that that includes a flattened representation of the portion of the conversation thread.