Ensemble Distillation for Structured Prediction: Calibrated, Accurate, Fast—Choose Three

Steven Reich, David Mueller, Nicholas Andrews


Abstract
Modern neural networks do not always produce well-calibrated predictions, even when trained with a proper scoring function such as cross-entropy. In classification settings, simple methods such as isotonic regression or temperature scaling may be used in conjunction with a held-out dataset to calibrate model outputs. However, extending these methods to structured prediction is not always straightforward or effective; furthermore, a held-out calibration set may not always be available. In this paper, we study ensemble distillation as a general framework for producing well-calibrated structured prediction models while avoiding the prohibitive inference-time cost of ensembles. We validate this framework on two tasks: named-entity recognition and machine translation. We find that, across both tasks, ensemble distillation produces models which retain much of, and occasionally improve upon, the performance and calibration benefits of ensembles, while only requiring a single model during test-time.
Anthology ID:
2020.emnlp-main.450
Volume:
Proceedings of the 2020 Conference on Empirical Methods in Natural Language Processing (EMNLP)
Month:
November
Year:
2020
Address:
Online
Editors:
Bonnie Webber, Trevor Cohn, Yulan He, Yang Liu
Venue:
EMNLP
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
5583–5595
Language:
URL:
https://aclanthology.org/2020.emnlp-main.450
DOI:
10.18653/v1/2020.emnlp-main.450
Bibkey:
Cite (ACL):
Steven Reich, David Mueller, and Nicholas Andrews. 2020. Ensemble Distillation for Structured Prediction: Calibrated, Accurate, Fast—Choose Three. In Proceedings of the 2020 Conference on Empirical Methods in Natural Language Processing (EMNLP), pages 5583–5595, Online. Association for Computational Linguistics.
Cite (Informal):
Ensemble Distillation for Structured Prediction: Calibrated, Accurate, Fast—Choose Three (Reich et al., EMNLP 2020)
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PDF:
https://preview.aclanthology.org/nschneid-patch-4/2020.emnlp-main.450.pdf
Video:
 https://slideslive.com/38939205