1. A computer-implemented method, comprising: receiving, by one or more server devices, history data for a document, the history data comprising an appearance date for each of a plurality of links to the document; determining, by one or more processors of the one or more server devices and from the history data, that there has been a decrease in a rate or quantity of appearances of new links that point to the document over time, and then classifying the document as stale, the determining that there has been a decrease in the rate or quantity of appearances of new links that point to the document over time comprising: comparing an oldest appearance date of the appearance dates, of the links to the document, to an oldest appearance date of the appearance dates of a group of newest links to the document, each link in the group of newest links to the document having an appearance date that is within a percentage of most recent appearance dates of the links to the document; based on classifying the document as stale, decreasing, by the one or more processors of the one or more server devices, an initial score for the document, resulting in an altered score; and ranking, by the one or more processors of the one or more server devices, the document with regard to at least one other document based on the altered score.
1. A computer-implemented method, comprising: receiving, by one or more server devices, history data for a document, the history data comprising an appearance date for each of a plurality of links to the document; determining, by one or more processors of the one or more server devices and from the history data, that there has been a decrease in a rate or quantity of appearances of new links that point to the document over time, and then classifying the document as stale, the determining that there has been a decrease in the rate or quantity of appearances of new links that point to the document over time comprising: comparing an oldest appearance date of the appearance dates, of the links to the document, to an oldest appearance date of the appearance dates of a group of newest links to the document, each link in the group of newest links to the document having an appearance date that is within a percentage of most recent appearance dates of the links to the document; based on classifying the document as stale, decreasing, by the one or more processors of the one or more server devices, an initial score for the document, resulting in an altered score; and ranking, by the one or more processors of the one or more server devices, the document with regard to at least one other document based on the altered score. 7. The method of claim 1 , where the history data is first history data, and where the document is a first document, the method further comprising: receiving second history data for a second document, the second history data comprising a disappearance date for each of a plurality of links to the second document; determining, based on the second history data, that there has been a decrease in a rate or quantity of disappearances of links that point to the second document over time; classifying the second document as stale based on determining that there has been a decrease in the rate or quantity of disappearances of links that point to the second document over time; and decreasing an initial score for the second document based on classifying the second document as stale.