On the Stability of System Rankings at WMT

Rebecca Knowles


Abstract
The current approach to collecting human judgments of machine translation quality for the news translation task at WMT – segment rating with document context – is the most recent in a sequence of changes to WMT human annotation protocol. As these annotation protocols have changed over time, they have drifted away from some of the initial statistical assumptions underpinning them, with consequences that call the validity of WMT news task system rankings into question. In simulations based on real data, we show that the rankings can be influenced by the presence of outliers (high- or low-quality systems), resulting in different system rankings and clusterings. We also examine questions of annotation task composition and how ease or difficulty of translating different documents may influence system rankings. We provide discussion of ways to analyze these issues when considering future changes to annotation protocols.
Anthology ID:
2021.wmt-1.56
Volume:
Proceedings of the Sixth Conference on Machine Translation
Month:
November
Year:
2021
Address:
Online
Editors:
Loic Barrault, Ondrej Bojar, Fethi Bougares, Rajen Chatterjee, Marta R. Costa-jussa, Christian Federmann, Mark Fishel, Alexander Fraser, Markus Freitag, Yvette Graham, Roman Grundkiewicz, Paco Guzman, Barry Haddow, Matthias Huck, Antonio Jimeno Yepes, Philipp Koehn, Tom Kocmi, Andre Martins, Makoto Morishita, Christof Monz
Venue:
WMT
SIG:
SIGMT
Publisher:
Association for Computational Linguistics
Note:
Pages:
464–477
Language:
URL:
https://aclanthology.org/2021.wmt-1.56
DOI:
Bibkey:
Cite (ACL):
Rebecca Knowles. 2021. On the Stability of System Rankings at WMT. In Proceedings of the Sixth Conference on Machine Translation, pages 464–477, Online. Association for Computational Linguistics.
Cite (Informal):
On the Stability of System Rankings at WMT (Knowles, WMT 2021)
Copy Citation:
PDF:
https://preview.aclanthology.org/nschneid-patch-3/2021.wmt-1.56.pdf
Video:
 https://preview.aclanthology.org/nschneid-patch-3/2021.wmt-1.56.mp4
Code
 nrc-cnrc/wmt-stability