What Comes Next? Evaluating Uncertainty in Neural Text Generators Against Human Production Variability

Mario Giulianelli, Joris Baan, Wilker Aziz, Raquel Fernández, Barbara Plank


Abstract
In Natural Language Generation (NLG) tasks, for any input, multiple communicative goals are plausible, and any goal can be put into words, or produced, in multiple ways. We characterise the extent to which human production varies lexically, syntactically, and semantically across four NLG tasks, connecting human production variability to aleatoric or data uncertainty. We then inspect the space of output strings shaped by a generation system’s predicted probability distribution and decoding algorithm to probe its uncertainty. For each test input, we measure the generator’s calibration to human production variability. Following this instance-level approach, we analyse NLG models and decoding strategies, demonstrating that probing a generator with multiple samples and, when possible, multiple references, provides the level of detail necessary to gain understanding of a model’s representation of uncertainty.
Anthology ID:
2023.emnlp-main.887
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:
14349–14371
Language:
URL:
https://aclanthology.org/2023.emnlp-main.887
DOI:
10.18653/v1/2023.emnlp-main.887
Bibkey:
Cite (ACL):
Mario Giulianelli, Joris Baan, Wilker Aziz, Raquel Fernández, and Barbara Plank. 2023. What Comes Next? Evaluating Uncertainty in Neural Text Generators Against Human Production Variability. In Proceedings of the 2023 Conference on Empirical Methods in Natural Language Processing, pages 14349–14371, Singapore. Association for Computational Linguistics.
Cite (Informal):
What Comes Next? Evaluating Uncertainty in Neural Text Generators Against Human Production Variability (Giulianelli et al., EMNLP 2023)
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PDF:
https://aclanthology.org/2023.emnlp-main.887.pdf
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 https://aclanthology.org/2023.emnlp-main.887.mp4