1. A method, performed by one or more server devices, of determining the freshness of a first document, comprising: identifying, by a processor of the one or more server devices, a set of second documents that each contains a link to the first document; determining, by a processor of the one or more server devices, a freshness attribute associated with each document of the set of second documents, where the freshness attribute indicates when each document was last modified; assigning, by a processor of the one or more server devices, a freshness score to the first document based on the freshness attribute associated with each document of the set of second documents; and ranking, by a processor of the one or more server devices, the first document with respect to at least one other document based on the freshness score assigned to the first document.
1. A method, performed by one or more server devices, of determining the freshness of a first document, comprising: identifying, by a processor of the one or more server devices, a set of second documents that each contains a link to the first document; determining, by a processor of the one or more server devices, a freshness attribute associated with each document of the set of second documents, where the freshness attribute indicates when each document was last modified; assigning, by a processor of the one or more server devices, a freshness score to the first document based on the freshness attribute associated with each document of the set of second documents; and ranking, by a processor of the one or more server devices, the first document with respect to at least one other document based on the freshness score assigned to the first document. 5. The method of claim 1 , assigning a freshness score to the first document further comprises: assigning a low freshness score to the first document if a majority of documents of the set of second documents have associated freshness attributes that indicate that the corresponding documents are not fresh.