12. The method of claim 1 , wherein: each data file comprises data about a plurality of n-grams; each n-gram comprises a current text element and a text element history, the text element history comprising text elements preceding the current text element of the n-gram; and the n-grams about which data is included in a given data file include those n-grams found in the corpus from which the given data file was derived that have one of the text elements associated with the given data file as a most recent text element in the histories of the respective n-grams.
12. The method of claim 1 , wherein: each data file comprises data about a plurality of n-grams; each n-gram comprises a current text element and a text element history, the text element history comprising text elements preceding the current text element of the n-gram; and the n-grams about which data is included in a given data file include those n-grams found in the corpus from which the given data file was derived that have one of the text elements associated with the given data file as a most recent text element in the histories of the respective n-grams. 13. The method of claim 12 , wherein a data file in the first set of data files is considered associated with a similar set of text elements as is associated with the data file in the second set of data files if the data files share a similar set of text elements as the most-recent text elements in the histories of the n-grams about which data is stored in the data files.