Semi-supervised Sentiment Classification using Ranked Opinion Words

This work proposes a semi-supervised sentiment classification method which is based on the co-training framework. The proposed method needs to construct three sentiment classifiers. We use common text features to construct the first classifier. We extract opinion words from consumer reviews, and then we ranked these opinion words according to their importance. We also employ extracted opinion words and the ranked co-occurrence opinion words of the extracted opinion words of each review to get the second sentiment classifier. A third sentiment classifier comes into being using non-opinion text features from each review. Based on co-training semi-supervised learning framework, we use the three sentiment classifiers to iteratively get the final sentiment classifier. Experimental results show that our proposed method has better performance than the Self-learning SVM method and the Naive co-training SVM method.