Unsupervised Learning of Semantic Orientation from a Hundred-Billion-Word Corpus
<|reference_start|>Unsupervised Learning of Semantic Orientation from a Hundred-Billion-Word Corpus: The evaluative character of a word is called its semantic orientation. A positive semantic orientation implies desirability (e.g., "honest", "intrepid") and a negative semantic orientation implies undesirability (e.g., "disturbing", "superfluous"). This paper introduces a simple algorithm for unsupervised learning of semantic orientation from extremely large corpora. The method involves issuing queries to a Web search engine and using pointwise mutual information to analyse the results. The algorithm is empirically evaluated using a training corpus of approximately one hundred billion words -- the subset of the Web that is indexed by the chosen search engine. Tested with 3,596 words (1,614 positive and 1,982 negative), the algorithm attains an accuracy of 80%. The 3,596 test words include adjectives, adverbs, nouns, and verbs. The accuracy is comparable with the results achieved by Hatzivassiloglou and McKeown (1997), using a complex four-stage supervised learning algorithm that is restricted to determining the semantic orientation of adjectives.<|reference_end|>
@article{turney2002unsupervised,
    title={Unsupervised Learning of Semantic Orientation from a
  Hundred-Billion-Word Corpus},
    author={Peter D. Turney (National Research Council of Canada), Michael L.
  Littman (Stowe Research)},
    journal={arXiv preprint arXiv:cs/0212012},
    year={2002},
    number={NRC-44929},
    archivePrefix={arXiv},
    eprint={cs/0212012},
    primaryClass={cs.LG cs.IR}
}