16. The non-transitory computer-readable storage medium as recited in claim 15 , wherein the first word and the second word co-occur in one or more blocks of text in the plurality of documents, and wherein the count is based at least in part on a third quantity of blocks of text in the plurality of documents in which the first word and the second word co-occur.
16. The non-transitory computer-readable storage medium as recited in claim 15 , wherein the first word and the second word co-occur in one or more blocks of text in the plurality of documents, and wherein the count is based at least in part on a third quantity of blocks of text in the plurality of documents in which the first word and the second word co-occur. 17. The non-transitory computer-readable storage medium as recited in claim 16 , wherein the first quantity of occurrences of the first word for the plurality of documents comprises a quantity of blocks of text that contain the first word, and the second quantity of occurrences of the second word for the plurality of documents comprises a quantity of blocks of text that contain the second word; wherein the count accounts for an overcorrelation of the first word and the second word in same blocks of text in the plurality of documents.