A Simple but Effective Method to Incorporate Multi-turn Context with BERT for Conversational Machine Comprehension

Yasuhito Ohsugi, Itsumi Saito, Kyosuke Nishida, Hisako Asano, Junji Tomita


Abstract
Conversational machine comprehension (CMC) requires understanding the context of multi-turn dialogue. Using BERT, a pretraining language model, has been successful for single-turn machine comprehension, while modeling multiple turns of question answering with BERT has not been established because BERT has a limit on the number and the length of input sequences. In this paper, we propose a simple but effective method with BERT for CMC. Our method uses BERT to encode a paragraph independently conditioned with each question and each answer in a multi-turn context. Then, the method predicts an answer on the basis of the paragraph representations encoded with BERT. The experiments with representative CMC datasets, QuAC and CoQA, show that our method outperformed recently published methods (+0.8 F1 on QuAC and +2.1 F1 on CoQA). In addition, we conducted a detailed analysis of the effects of the number and types of dialogue history on the accuracy of CMC, and we found that the gold answer history, which may not be given in an actual conversation, contributed to the model performance most on both datasets.
Anthology ID:
W19-4102
Volume:
Proceedings of the First Workshop on NLP for Conversational AI
Month:
August
Year:
2019
Address:
Florence, Italy
Editors:
Yun-Nung Chen, Tania Bedrax-Weiss, Dilek Hakkani-Tur, Anuj Kumar, Mike Lewis, Thang-Minh Luong, Pei-Hao Su, Tsung-Hsien Wen
Venue:
ACL
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
11–17
Language:
URL:
https://aclanthology.org/W19-4102
DOI:
10.18653/v1/W19-4102
Bibkey:
Cite (ACL):
Yasuhito Ohsugi, Itsumi Saito, Kyosuke Nishida, Hisako Asano, and Junji Tomita. 2019. A Simple but Effective Method to Incorporate Multi-turn Context with BERT for Conversational Machine Comprehension. In Proceedings of the First Workshop on NLP for Conversational AI, pages 11–17, Florence, Italy. Association for Computational Linguistics.
Cite (Informal):
A Simple but Effective Method to Incorporate Multi-turn Context with BERT for Conversational Machine Comprehension (Ohsugi et al., ACL 2019)
Copy Citation:
PDF:
https://aclanthology.org/W19-4102.pdf
Data
CoQAQuACSQuAD