An Empirical Study on Leveraging Position Embeddings for Target-oriented Opinion Words Extraction

Samuel Mensah, Kai Sun, Nikolaos Aletras


Abstract
Target-oriented opinion words extraction (TOWE) (Fan et al., 2019b) is a new subtask of target-oriented sentiment analysis that aims to extract opinion words for a given aspect in text. Current state-of-the-art methods leverage position embeddings to capture the relative position of a word to the target. However, the performance of these methods depends on the ability to incorporate this information into word representations. In this paper, we explore a variety of text encoders based on pretrained word embeddings or language models that leverage part-of-speech and position embeddings, aiming to examine the actual contribution of each component in TOWE. We also adapt a graph convolutional network (GCN) to enhance word representations by incorporating syntactic information. Our experimental results demonstrate that BiLSTM-based models can effectively encode position information into word representations while using a GCN only achieves marginal gains. Interestingly, our simple methods outperform several state-of-the-art complex neural structures.
Anthology ID:
2021.emnlp-main.722
Volume:
Proceedings of the 2021 Conference on Empirical Methods in Natural Language Processing
Month:
November
Year:
2021
Address:
Online and Punta Cana, Dominican Republic
Editors:
Marie-Francine Moens, Xuanjing Huang, Lucia Specia, Scott Wen-tau Yih
Venue:
EMNLP
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
9174–9179
Language:
URL:
https://aclanthology.org/2021.emnlp-main.722
DOI:
10.18653/v1/2021.emnlp-main.722
Bibkey:
Cite (ACL):
Samuel Mensah, Kai Sun, and Nikolaos Aletras. 2021. An Empirical Study on Leveraging Position Embeddings for Target-oriented Opinion Words Extraction. In Proceedings of the 2021 Conference on Empirical Methods in Natural Language Processing, pages 9174–9179, Online and Punta Cana, Dominican Republic. Association for Computational Linguistics.
Cite (Informal):
An Empirical Study on Leveraging Position Embeddings for Target-oriented Opinion Words Extraction (Mensah et al., EMNLP 2021)
Copy Citation:
PDF:
https://aclanthology.org/2021.emnlp-main.722.pdf
Video:
 https://aclanthology.org/2021.emnlp-main.722.mp4
Code
 samensah/encoders_towe_emnlp2021