22. The system of claim 19 , wherein the semantic processing module further comprises a substitute input text string generator in communication with the content score generator to generate candidate substitute input text strings.
22. The system of claim 19 , wherein the semantic processing module further comprises a substitute input text string generator in communication with the content score generator to generate candidate substitute input text strings. 23. The system of claim 22 , wherein the substitute input text string generator comprises: a sub-phrase identifier to identify sub-phrases in the input text string, each sub-phrase comprising a number of characters less than a plurality of characters forming the input text string; a substitute sub-phrase generator to generate a plurality of substitute sub-phrases, each substitute sub-phrase associated with one of the sub-phrases in the input text string; and a substitute sub-phrase assembly module to form a plurality of candidate substitute input data strings, each candidate substitute input data string comprising a unique combination of the input data string and at least one of the plurality of substitute sub-phrases.