Weakly-supervised Text Classification Based on Keyword Graph

Lu Zhang, Jiandong Ding, Yi Xu, Yingyao Liu, Shuigeng Zhou


Abstract
Weakly-supervised text classification has received much attention in recent years for it can alleviate the heavy burden of annotating massive data. Among them, keyword-driven methods are the mainstream where user-provided keywords are exploited to generate pseudo-labels for unlabeled texts. However, existing methods treat keywords independently, thus ignore the correlation among them, which should be useful if properly exploited. In this paper, we propose a novel framework called ClassKG to explore keyword-keyword correlation on keyword graph by GNN. Our framework is an iterative process. In each iteration, we first construct a keyword graph, so the task of assigning pseudo labels is transformed to annotating keyword subgraphs. To improve the annotation quality, we introduce a self-supervised task to pretrain a subgraph annotator, and then finetune it. With the pseudo labels generated by the subgraph annotator, we then train a text classifier to classify the unlabeled texts. Finally, we re-extract keywords from the classified texts. Extensive experiments on both long-text and short-text datasets show that our method substantially outperforms the existing ones.
Anthology ID:
2021.emnlp-main.222
Volume:
Proceedings of the 2021 Conference on Empirical Methods in Natural Language Processing
Month:
November
Year:
2021
Address:
Online and Punta Cana, Dominican Republic
Venue:
EMNLP
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
2803–2813
Language:
URL:
https://aclanthology.org/2021.emnlp-main.222
DOI:
10.18653/v1/2021.emnlp-main.222
Bibkey:
Cite (ACL):
Lu Zhang, Jiandong Ding, Yi Xu, Yingyao Liu, and Shuigeng Zhou. 2021. Weakly-supervised Text Classification Based on Keyword Graph. In Proceedings of the 2021 Conference on Empirical Methods in Natural Language Processing, pages 2803–2813, Online and Punta Cana, Dominican Republic. Association for Computational Linguistics.
Cite (Informal):
Weakly-supervised Text Classification Based on Keyword Graph (Zhang et al., EMNLP 2021)
Copy Citation:
PDF:
https://preview.aclanthology.org/update-css-js/2021.emnlp-main.222.pdf
Code
 zhanglu-cst/classkg
Data
AG NewsIMDb Movie Reviews