Challenges for Sentence Level Opinion Detection in Blogs

The Opinion Detection from blogs has always been a challenge for researchers. However with the introduction of Blog track in TREC 2006, a considerable improvement has been seen in this field at document level. But now it is the time when researchers are thinking to shift their orientation from opinion finding at document level to opinion finding at sentence or passage level. In this paper, we investigate the challenges the researchers might face with sentence-level opinion detection and have tried to demonstrate them with few examples. Our work also includes annotation of a small set of opinionated sentences by two annotators. These Annotators annotate the sentences by labels Positive or Negative. The results of annotation prove that task of opinion detection on sentence-level is more challenging task than opinion detection on document level. In addition, we also discuss the importance of sentence-level opinion detection. Our work can give a new direction to researchers to think and work on.