Leveraging multiple features for document sentiment classification

Abstract

Sentiment classification is an important research task in Natural Language Processing. To fulfill this type of classification, previous works have focused on leveraging task-specific features. However, they only notice part of the related features. Also, state-of-the-art methods based on neural networks often ignore traditional features. This paper proposes a novel text sentiment classification method that learns the representation of texts by hierarchically incorporating multiple features. More specifically, we design different representations for sentiment words according to the polarity of labeled texts and whether negation exists; we distinguish words with different part-of-speech tags; emoticons, if there are, are to optimize the word vectors obtained in the previous step; apart from word embeddings, character embeddings are also trained. We use a deep neural network to get a sentence-level representation from both word and character sequence. For documents with at least two sentences, we use a hierarchical structure and design a rule to give more weight to import sentences empirically to get a document-level representation. Experimental results on open datasets demonstrate that our method could effectively improve the sentiment classification performance compared with the basic models and state-of-the-art methods.