15. The computer-readable storage medium of claim 12 wherein each text unit comprises a plurality of words, and wherein the method further comprises bucketing the first and second sets of features into ranges, and utilizing the ranges in the classification model.
15. The computer-readable storage medium of claim 12 wherein each text unit comprises a plurality of words, and wherein the method further comprises bucketing the first and second sets of features into ranges, and utilizing the ranges in the classification model. 16. The computer-readable storage medium of claim 15 wherein each text unit comprises a line of text, and wherein the classification model uses a weighted linear combination of the ranges.