Distinguishing between facts and opinions for sentiment analysis: Survey and challenges

Sentiment analysis requires a lot of information coming from different sources and about different topics to be retrieved and fused. For this reason, one of the most important subtasks of sentiment analysis is subjectivity detection, i.e., the removal of ‘factual’ or ‘neutral’ comments that lack sentiment. It is possibly the most essential subtask of sentiment analysis as sentiment classifiers are often optimized to categorize text as either...