8. A non-transitory computer-readable memory device storing programming instructions, the instructions comprising: one or more instructions executable by a processor to cause the processor to determine a measure of how anchor text, that is associated with a link pointing to a document and that includes character text referring to a content of the document, changes over time; one or more instructions executable by the processor to cause the processor to generate a score for the document based on the measure of how the anchor text, associated with the link pointing to the document, changes over time; and one or more instructions executable by the processor to cause the processor to rank the document with regard to at least one other document based on the score.
8. A non-transitory computer-readable memory device storing programming instructions, the instructions comprising: one or more instructions executable by a processor to cause the processor to determine a measure of how anchor text, that is associated with a link pointing to a document and that includes character text referring to a content of the document, changes over time; one or more instructions executable by the processor to cause the processor to generate a score for the document based on the measure of how the anchor text, associated with the link pointing to the document, changes over time; and one or more instructions executable by the processor to cause the processor to rank the document with regard to at least one other document based on the score. 9. The computer-readable memory device of claim 8 , where the anchor text is one of a plurality of anchor text associated with a plurality of links pointing to the document; where the one or more instructions to determine the measure of how the anchor text changes over time include: one or more instructions to analyze, over time, a respective appearance of the plurality of anchor text, and one or more instructions to identify a rate of increase in the respective appearance of the analyzed plurality of anchor text.