User feedback regarding sentiments of social posts is used to improve sentiment assignment for social analysis. The user feedback is used to generate sentiment tuning data, which may include assignments between reference sentiments and reference social posts. Sentiments of new social posts may be determined by applying the sentiment tuning data to an analysis of the new social posts. Sentiments of new social posts may also be determined by applying entries from one or more lexical dictionaries to the new social posts using natural language processing. At least some of the entries can be automatically generated from the user feedback or can be supplied by a user separate from the user feedback.