Knowledge Transfer from Answer Ranking to Answer Generation

Matteo Gabburo, Rik Koncel-Kedziorski, Siddhant Garg, Luca Soldaini, Alessandro Moschitti


Abstract
Recent studies show that Question Answering (QA) based on Answer Sentence Selection (AS2) can be improved by generating an improved answer from the top-k ranked answer sentences (termed GenQA). This allows for synthesizing the information from multiple candidates into a concise, natural-sounding answer. However, creating large-scale supervised training data for GenQA models is very challenging. In this paper, we propose to train a GenQA model by transferring knowledge from a trained AS2 model, to overcome the aforementioned issue. First, we use an AS2 model to produce a ranking over answer candidates for a set of questions. Then, we use the top ranked candidate as the generation target, and the next k top ranked candidates as context for training a GenQA model. We also propose to use the AS2 model prediction scores for loss weighting and score-conditioned input/output shaping, to aid the knowledge transfer. Our evaluation on three public and one large industrial datasets demonstrates the superiority of our approach over the AS2 baseline, and GenQA trained using supervised data.
Anthology ID:
2022.emnlp-main.645
Volume:
Proceedings of the 2022 Conference on Empirical Methods in Natural Language Processing
Month:
December
Year:
2022
Address:
Abu Dhabi, United Arab Emirates
Editors:
Yoav Goldberg, Zornitsa Kozareva, Yue Zhang
Venue:
EMNLP
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
9481–9495
Language:
URL:
https://aclanthology.org/2022.emnlp-main.645
DOI:
10.18653/v1/2022.emnlp-main.645
Bibkey:
Cite (ACL):
Matteo Gabburo, Rik Koncel-Kedziorski, Siddhant Garg, Luca Soldaini, and Alessandro Moschitti. 2022. Knowledge Transfer from Answer Ranking to Answer Generation. In Proceedings of the 2022 Conference on Empirical Methods in Natural Language Processing, pages 9481–9495, Abu Dhabi, United Arab Emirates. Association for Computational Linguistics.
Cite (Informal):
Knowledge Transfer from Answer Ranking to Answer Generation (Gabburo et al., EMNLP 2022)
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PDF:
https://aclanthology.org/2022.emnlp-main.645.pdf