Sentiment-aligned Topic Models for Product Aspect Rating Prediction

Aspect-based opinion mining has attracted lots of attention today. In this thesis, we address the problem of product aspect rating prediction, where we would like to extract the product aspects, and predict aspect ratings simultaneously. Topic models have been widely adapted to jointly model aspects and sentiments, but existing models may not do the prediction task well due to their weakness in sentiment extraction. The sentiment topics usually do not have clear correspondence to commonly used ratings, and the model may fail to extract certain kinds of sentiments due to skewed data. To tackle this problem, we propose a sentiment-aligned topic model(SATM), where we incorporate two types of external knowledge: product-level overall rating distribution and word-level sentiment lexicon. Experiments on real dataset demonstrate that SATM is effective on product aspect rating prediction, and it achieves better performance compared to the existing approaches.