DiffuSyn: A Diffusion-Driven Framework With Syntactic Dependency for Aspect Sentiment Triplet Extraction

Abstract

<p>Aspect Sentiment Triplet Extraction (ASTE) is a fine-grained sentiment analysis task that involves identifying aspect and opinion terms and conducting sentiment analysis for each aspect-opinion pair. We categorize existing methods into tagging-based, span-based, and generation methods. However, despite notable achievements, these methods still face certain challenges: span-based methods struggle to distinguish similar spans, and generation methods are prone to slower decoding speeds. To address these challenges, we propose a novel ASTE framework, called DiffuSyn, which leverages diffusion models and syntactic dependency parsing to improve the performance of sentiment analysis. Specifically, we first add Gaussian noise to the indices at the beginning and end of aspect words and opinion words in sentences based on a non-autoregressive diffusion model. We obtain accurate boundaries of aspect and opinion terms through boundary denoising, and thus identify precise spans. Secondly, we introduce a syntactic dependency parser to capture the syntactic dependencies within review sentences, thereby providing effective syntactic information for sentiment analysis. Finally, we complete the matching of aspects and opinions by leveraging the extracted boundaries and syntactic semantic information, facilitating the prediction of sentiment relationships. We conduct experiments on four public datasets (ASTE-Data-V2), and the results indicate the effectiveness of our approach in the ASTE task. Furthermore, our method achieves state-of-the-art performance in both Aspect Term Extraction (ATE) and Opinion Term Extraction (OTE) tasks.</p>