The system uses two separate classifiers, one for phrase-level sentiment and one for tweet-level.
Both classifiers use the following features. For a text span (phrase or tweet)
The phrase-level classifier also uses the following additional features:
We used the features derived from the following lexicons: AFINN, Opinion Lexicon, Brown Clusters, Hashtag Emotion, Sentiment140, Hashtag Sentiment, Subjectivity, and General Inquirer.
We used the following features for lexicons that provided scores: