15. The system of claim 13 , further comprising: an analysis module configured to identify a set of high-sentiment documents based on scoring sentiments expressed by one or more domain-specific documents; wherein the lexicon module is configured to create the domain-specific sentiment lexicon based at least in part on the set of high-sentiment documents.
15. The system of claim 13 , further comprising: an analysis module configured to identify a set of high-sentiment documents based on scoring sentiments expressed by one or more domain-specific documents; wherein the lexicon module is configured to create the domain-specific sentiment lexicon based at least in part on the set of high-sentiment documents. 16. The system of claim 15 , wherein the lexicon module is further configured to: identify n-grams occurring within the documents in the set of high-sentiment documents; filter the identified n-grams to remove n-grams unlikely to express sentiment in the specified domain; and store the filtered n-grams as the domain-specific sentiment lexicon.