Subjectivity Lexicon for Czech: Implementation and Improvements

The aim of this paper is to introduce the Czech subjectivity lexicon, a new lexical resource for sentiment analysis in Czech. We describe particular stages of the manual refinement of the lexicon and demonstrate its use in the state-of-the art polarity classifiers, namely the Maximum Entropy classifier. We test the success rate of the system enriched with the dictionary on different data sets, compare the results and suggest some further improvements of the lexicon-based classification system.