Jasy Liew Suet Yan
2024
GenABSA-Vec: Generative Aspect-Based Sentiment Feature Vectorization for Document-Level Sentiment Classification
Liu Minkang
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Jasy Liew Suet Yan
Proceedings of the 22nd Annual Workshop of the Australasian Language Technology Association
Currently, document-level sentiment classification focuses on extracting text features directly using a deep neural network and representing the document through a high-dimensional vector. Such sentiment classifiers that directly accept text as input may not be able to capture more fine-grained sentiment representations based on different aspects in a review, which could be informative for document-level sentiment classification. We propose a method to construct a GenABSA feature vector containing five aspect-sentiment scores to represent each review document. We first generate an aspect-based sentiment analysis (ABSA) quadruple by finetuning the T5 pre-trained language model. The aspect term from each quadruple is then scored for sentiment using our sentiment lexicon fusion approach, SentLex-Fusion. For each document, we then aggregate the sentiment score belonging to the same aspect to derive the aspect-sentiment feature vector, which is subsequently used as input to train a document-level sentiment classifier. Based on a Yelp restaurant review corpus labeled with sentiment polarity containing 2040 documents, the sentiment classifier trained with ABSA features aggregated using geometric mean achieved the best performance compared to the baselines.