Modelling Context and Syntactical Features for Aspect-based Sentiment Analysis

Minh Hieu Phan, Philip O. Ogunbona


Abstract
The aspect-based sentiment analysis (ABSA) consists of two conceptual tasks, namely an aspect extraction and an aspect sentiment classification. Rather than considering the tasks separately, we build an end-to-end ABSA solution. Previous works in ABSA tasks did not fully leverage the importance of syntactical information. Hence, the aspect extraction model often failed to detect the boundaries of multi-word aspect terms. On the other hand, the aspect sentiment classifier was unable to account for the syntactical correlation between aspect terms and the context words. This paper explores the grammatical aspect of the sentence and employs the self-attention mechanism for syntactical learning. We combine part-of-speech embeddings, dependency-based embeddings and contextualized embeddings (e.g. BERT, RoBERTa) to enhance the performance of the aspect extractor. We also propose the syntactic relative distance to de-emphasize the adverse effects of unrelated words, having weak syntactic connection with the aspect terms. This increases the accuracy of the aspect sentiment classifier. Our solutions outperform the state-of-the-art models on SemEval-2014 dataset in both two subtasks.
Anthology ID:
2020.acl-main.293
Volume:
Proceedings of the 58th Annual Meeting of the Association for Computational Linguistics
Month:
July
Year:
2020
Address:
Online
Editors:
Dan Jurafsky, Joyce Chai, Natalie Schluter, Joel Tetreault
Venue:
ACL
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
3211–3220
Language:
URL:
https://aclanthology.org/2020.acl-main.293
DOI:
10.18653/v1/2020.acl-main.293
Bibkey:
Cite (ACL):
Minh Hieu Phan and Philip O. Ogunbona. 2020. Modelling Context and Syntactical Features for Aspect-based Sentiment Analysis. In Proceedings of the 58th Annual Meeting of the Association for Computational Linguistics, pages 3211–3220, Online. Association for Computational Linguistics.
Cite (Informal):
Modelling Context and Syntactical Features for Aspect-based Sentiment Analysis (Phan & Ogunbona, ACL 2020)
Copy Citation:
PDF:
https://aclanthology.org/2020.acl-main.293.pdf
Video:
 http://slideslive.com/38928810
Data
SemEval-2014 Task-4