11. A machine-readable medium comprising instructions related to classifying input text to a target classification system having two or more target classes, the instructions comprising: a first set of instructions for determining first and second scores based on the input text and one of the target classes, wherein the first score is based on: similarity of at least one or more portions of the input text to text associated with the one target class; or similarity of a set of one or more non-target classes associated with the input text and a set of one or more non-target classes associated with the one target class; and wherein the second score is based on: probability of the one target class given a set of one or more non-target classes associated with the input text; or probability of the one target class given at least a portion of the input text; a second set of instructions for determining a composite score based on the first and second scores; and a third set of instructions for comparing the composite score to a decision threshold.
11. A machine-readable medium comprising instructions related to classifying input text to a target classification system having two or more target classes, the instructions comprising: a first set of instructions for determining first and second scores based on the input text and one of the target classes, wherein the first score is based on: similarity of at least one or more portions of the input text to text associated with the one target class; or similarity of a set of one or more non-target classes associated with the input text and a set of one or more non-target classes associated with the one target class; and wherein the second score is based on: probability of the one target class given a set of one or more non-target classes associated with the input text; or probability of the one target class given at least a portion of the input text; a second set of instructions for determining a composite score based on the first and second scores; and a third set of instructions for comparing the composite score to a decision threshold. 14. The medium of claim 11 , further comprising instructions for classifying or recommending classification of, for one or more of the target classes, the input text to the target class based on the composite score and the decision threshold.