CASA-NLU: Context-Aware Self-Attentive Natural Language Understanding for Task-Oriented Chatbots

Arshit Gupta, Peng Zhang, Garima Lalwani, Mona Diab

Abstract
Natural Language Understanding (NLU) is a core component of dialog systems. It typically involves two tasks - Intent Classification (IC) and Slot Labeling (SL), which are then followed by a dialogue management (DM) component. Such NLU systems cater to utterances in isolation, thus pushing the problem of context management to DM. However, contextual information is critical to the correct prediction of intents in a conversation. Prior work on contextual NLU has been limited in terms of the types of contextual signals used and the understanding of their impact on the model. In this work, we propose a context-aware self-attentive NLU (CASA-NLU) model that uses multiple signals over a variable context window, such as previous intents, slots, dialog acts and utterances, in addition to the current user utterance. CASA-NLU outperforms a recurrent contextual NLU baseline on two conversational datasets, yielding a gain of up to 7% on the IC task. Moreover, a non-contextual variant of CASA-NLU achieves state-of-the-art performance on standard public datasets - SNIPS and ATIS.
Anthology ID:
D19-1127
Volume:
Proceedings of the 2019 Conference on Empirical Methods in Natural Language Processing and the 9th International Joint Conference on Natural Language Processing (EMNLP-IJCNLP)
Month:
November
Year:
2019
Address:
Hong Kong, China
Venues:
EMNLP | IJCNLP
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
1285–1290
Language:
URL:
https://aclanthology.org/D19-1127
DOI:
10.18653/v1/D19-1127
Bibkey:
Cite (ACL):
Arshit Gupta, Peng Zhang, Garima Lalwani, and Mona Diab. 2019. CASA-NLU: Context-Aware Self-Attentive Natural Language Understanding for Task-Oriented Chatbots. In Proceedings of the 2019 Conference on Empirical Methods in Natural Language Processing and the 9th International Joint Conference on Natural Language Processing (EMNLP-IJCNLP), pages 1285–1290, Hong Kong, China. Association for Computational Linguistics.
Cite (Informal):
CASA-NLU: Context-Aware Self-Attentive Natural Language Understanding for Task-Oriented Chatbots (Gupta et al., EMNLP-IJCNLP 2019)
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