We produce 4 features, two for each polarity: (1) the number of words such that 0 ≤p pos w < 0.4; (2) the number of words such that 0.4 ≤p pos w ≤ 1; similarity for the negative polarity.
we implemented a WordNet (Miller, 1995) based expansion that uses the 3 most frequent synonyms of the top sense of the seed word (WN-e).