title: Why is stemming important for sentimental analysis
body: <p>I am using seven lexicons to calculate sentimental scores on a data set containing forum posts. Apart from removing all noise such as whitespace, special char, digits and stopwords, why is it also important to stem the words?</p>
  
  <p>I am using Harvard.IV, Qdap, Henry's Financial dictionary and Loughran-McDonald Financial dictionary from SentimentAnalysis package, as well as AFINN, NRC and BING dictionaries.</p>