Enhancing Task-oriented Dialogue Systems with Generative Post-processing Networks

Atsumoto Ohashi, Ryuichiro Higashinaka


Abstract
Recently, post-processing networks (PPNs), which modify the outputs of arbitrary modules including non-differentiable ones in task-oriented dialogue systems, have been proposed. PPNs have successfully improved the dialogue performance by post-processing natural language understanding (NLU), dialogue state tracking (DST), and dialogue policy (Policy) modules with a classification-based approach. However, they cannot be applied to natural language generation (NLG) modules because the post-processing of the utterance output by the NLG module requires a generative approach. In this study, we propose a new post-processing component for NLG, generative post-processing networks (GenPPNs). For optimizing GenPPNs via reinforcement learning, the reward function incorporates dialogue act contribution, a new measure to evaluate the contribution of GenPPN-generated utterances with regard to task completion in dialogue. Through simulation and human evaluation experiments based on the MultiWOZ dataset, we confirmed that GenPPNs improve the task completion performance of task-oriented dialogue systems.
Anthology ID:
2023.emnlp-main.231
Volume:
Proceedings of the 2023 Conference on Empirical Methods in Natural Language Processing
Month:
December
Year:
2023
Address:
Singapore
Editors:
Houda Bouamor, Juan Pino, Kalika Bali
Venue:
EMNLP
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
3815–3828
Language:
URL:
https://aclanthology.org/2023.emnlp-main.231
DOI:
10.18653/v1/2023.emnlp-main.231
Bibkey:
Cite (ACL):
Atsumoto Ohashi and Ryuichiro Higashinaka. 2023. Enhancing Task-oriented Dialogue Systems with Generative Post-processing Networks. In Proceedings of the 2023 Conference on Empirical Methods in Natural Language Processing, pages 3815–3828, Singapore. Association for Computational Linguistics.
Cite (Informal):
Enhancing Task-oriented Dialogue Systems with Generative Post-processing Networks (Ohashi & Higashinaka, EMNLP 2023)
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PDF:
https://aclanthology.org/2023.emnlp-main.231.pdf
Video:
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