Semisupervised sentiment analysis method for online text reviews

• Published in: Journal of information science Vol. 47; no. 3; pp. 387 - 403
• Main Authors: Lee, Gyeong Taek, Kim, Chang Ouk, Song, Min
• Format: Journal Article
• Language: English
• Published: London, England SAGE Publications 01.06.2021; Bowker-Saur Ltd
• Subjects: Data mining; Datasets; Dictionaries; Machine learning; Product reviews; Sentiment analysis; Training; Websites; ensemble learning; Adaptive instance-based learning; lasso regression; semisupervised learning; sentiment analysis; word2vec
• ISSN: 0165-5515; 1741-6485
• DOI: 10.1177/0165551520910032

Sentiment analysis plays an important role in understanding individual opinions expressed in websites such as social media and product review sites. The common approaches to sentiment analysis use the sentiments carried by words that express opinions and are based on either supervised or unsupervised learning techniques. The unsupervised learning approach builds a word-sentiment dictionary, but it requires lengthy time periods and high costs to build a reliable dictionary. The supervised learning approach uses machine learning models to learn the sentiment scores of words; however, training a classifier model requires large amounts of labelled text data to achieve a good performance. In this article, we propose a semisupervised approach that performs well despite having only small amounts of labelled data available for training. The proposed method builds a base sentiment dictionary from a small training dataset using a lasso-based ensemble model with minimal human effort. The scores of words not in the training dataset are estimated using an adaptive instance-based learning model. In a pretrained word2vec model space, the sentiment values of the words in the dictionary are propagated to the words that did not exist in the training dataset. Through two experiments, we demonstrate that the performance of the proposed method is comparable to that of supervised learning models trained on large datasets.