Back to Reality: Leveraging Pattern-driven Modeling to Enable Affordable Sentiment Dependency Learning

Aspect-based Sentiment Classification (ABSC) is a challenging sub-task of traditional sentiment analysis. Due to the difficulty of handling potential correlations among sentiment polarities of multiple aspects, i.e., sentiment dependency, recent popular works tend to exploit syntactic information guiding sentiment dependency parsing. However, syntax information (e.g., syntactic dependency trees) usually occupies expensive computational resources in terms of the operation of the adjacent matrix. Instead, we define the consecutive aspects with the same sentiment as the sentiment cluster in the case that we find that most sentiment dependency occurs between adjacent aspects. Motivated by this finding, we propose the sentiment patterns (SP) to guide the model dependency learning. Thereafter, we introduce the local sentiment aggregating (LSA) mechanism to focus on learning the sentiment dependency in the sentiment cluster. The LSA is more efficient than existing dependency tree-based models due to the absence of additional dependency matrix constructing and modeling. Furthermore, we propose differential weighting for aggregation window building to measure the importance of sentiment dependency. Experiments on four public datasets show that our models achieve state-of-the-art performance with especially improvement on learning sentiment cluster.