In particular, (Balahur and Steinberger, 2009) identified the main tasks for news opinion mining: (1) the definition of the target, (2) the separation of the good and bad news content from the good and bad sentiment expressed on the target and (3) the analysis of clearly marked opinion that is expressed explicitly, not needing interpretation or the use of world knowledge.
they show that it is important to distinguish three different possible views on newspaper articles: author, reader and text.