How to (Properly) Evaluate Cross-Lingual Word Embeddings: On Strong Baselines, Comparative Analyses, and Some Misconceptions

Goran Glavaš, Robert Litschko, Sebastian Ruder, Ivan Vulić


Abstract
Cross-lingual word embeddings (CLEs) facilitate cross-lingual transfer of NLP models. Despite their ubiquitous downstream usage, increasingly popular projection-based CLE models are almost exclusively evaluated on bilingual lexicon induction (BLI). Even the BLI evaluations vary greatly, hindering our ability to correctly interpret performance and properties of different CLE models. In this work, we take the first step towards a comprehensive evaluation of CLE models: we thoroughly evaluate both supervised and unsupervised CLE models, for a large number of language pairs, on BLI and three downstream tasks, providing new insights concerning the ability of cutting-edge CLE models to support cross-lingual NLP. We empirically demonstrate that the performance of CLE models largely depends on the task at hand and that optimizing CLE models for BLI may hurt downstream performance. We indicate the most robust supervised and unsupervised CLE models and emphasize the need to reassess simple baselines, which still display competitive performance across the board. We hope our work catalyzes further research on CLE evaluation and model analysis.
Anthology ID:
P19-1070
Volume:
Proceedings of the 57th Annual Meeting of the Association for Computational Linguistics
Month:
July
Year:
2019
Address:
Florence, Italy
Venue:
ACL
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
710–721
Language:
URL:
https://aclanthology.org/P19-1070
DOI:
10.18653/v1/P19-1070
Bibkey:
Cite (ACL):
Goran Glavaš, Robert Litschko, Sebastian Ruder, and Ivan Vulić. 2019. How to (Properly) Evaluate Cross-Lingual Word Embeddings: On Strong Baselines, Comparative Analyses, and Some Misconceptions. In Proceedings of the 57th Annual Meeting of the Association for Computational Linguistics, pages 710–721, Florence, Italy. Association for Computational Linguistics.
Cite (Informal):
How to (Properly) Evaluate Cross-Lingual Word Embeddings: On Strong Baselines, Comparative Analyses, and Some Misconceptions (Glavaš et al., ACL 2019)
Copy Citation:
PDF:
https://aclanthology.org/P19-1070.pdf
Supplementary:
 P19-1070.Supplementary.pdf
Code
 codogogo/xling-eval
Data
MultiNLIXNLI