19. A system, comprising: a memory device to store computer-executable instructions; and one or more processors, to execute the computer-executable instructions, to: determine an amount or rate that a document moves positions in search result rankings over time; generate a score for the document based on the amount or rate that the document moves in the search result rankings over time; and rank the document with regard to at least one other document based on the score.
19. A system, comprising: a memory device to store computer-executable instructions; and one or more processors, to execute the computer-executable instructions, to: determine an amount or rate that a document moves positions in search result rankings over time; generate a score for the document based on the amount or rate that the document moves in the search result rankings over time; and rank the document with regard to at least one other document based on the score. 20. The system of claim 19 , where when determining the amount or rate that the document moves in search result rankings, the one or more processors are to: determine a number of positions that the document moves in the search result rankings.