Data Augmentation via Relation-Variant Discourse Recasting for Implicit Discourse Relation Recognition

Yikang Yang, Weihao Sun, Yu Hong, Zhipang Wang, Guodong Zhou


Abstract
Implicit discourse relation recognition (abbr., IDRR) is a task of automatically classifying semantic relations between pairwise arguments in the absence of explicit connectives. IDRR suffers from imbalanced data distribution of different relations. The current data augmentation approaches have relieved this problem to some extent. However, the incorporated discourse samples during augmentation lack customized contrastive effects. To address this issue, we propose to construct topic-relevant relation-inconsistent arguments for augmentation. Specifically, we implement a Relation-Variant Discourse Recasting (RVDR) approach. RVDR utilizes Qwen3-4B to paraphrase discourses under the forcible constraints of preserving inherent topics and transforming relation senses toward infrequent target relations. To avoid excessive divergent thinking of RVDR, we optimize the Qwen3-4B via reinforcement learning, where Group Relative Policy Optimization (GRPO) is used along with multiple task-specific rewards. Furthermore, rule-based filtering and confidence estimation are used to ensure data quality, which additionally enable two application modes, i.e., Confidence-based and Progressive Data Augmentation (i.e., CDA and PDA). Experiments on PDTB 2.0 and 3.0 show that RVDR-based CDA consistently improves IDRR performance across multiple backbones, including both encoder-only and decoder-only cases. It also allows the strong IDRR frameworks CP-KD and SCDN to be enhanced further. The code is publicly available.
Anthology ID:
2026.findings-emnlp.966
Volume:
Findings of the Association for Computational Linguistics: EMNLP 2026
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
Findings
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
20430–20444
Language:
URL:
https://aclanthology.org/2026.findings-emnlp.966/
DOI:
10.18653/2026.findings-emnlp.966
Bibkey:
Cite (ACL):
Yikang Yang, Weihao Sun, Yu Hong, Zhipang Wang, and Guodong Zhou. 2026. Data Augmentation via Relation-Variant Discourse Recasting for Implicit Discourse Relation Recognition. In Findings of the Association for Computational Linguistics: EMNLP 2026, pages 20430–20444, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Data Augmentation via Relation-Variant Discourse Recasting for Implicit Discourse Relation Recognition (Yang et al., Findings 2026)
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PDF:
https://aclanthology.org/2026.findings-emnlp.966.pdf