Credibility Adjusted Term Frequency: A Supervised Term Weighting Scheme   for Sentiment Analysis and Text Classification
  We provide a simple but novel supervised weighting scheme for adjusting term frequency in tf-idf for sentiment analysis and text classification. We compare our method to baseline weighting schemes and find that it outperforms them on multiple benchmarks. The method is robust and works well on both snippets and longer documents. 
Yoon Kim, Owen Zhang
cs.CL cs.IR