Representation Collapse in Machine Translation Through the Lens of Angular Dispersion

Evgeniia Tokarchuk, Maya K. Nachesa, Sergey Troshin, Vlad Niculae


Abstract
Modern neural translation models based on the Transformer architecture are known for their high performance, particularly when trained on high-resource datasets. A standard next-token prediction training strategy, while widely adopted in practice, may lead to overlooked artifacts such as representation collapse. Previous works have shown that this problem is especially pronounced in the representation of the deeper Transformer layers, where it often fails to efficiently utilize the geometric space. Representation collapse is even more evident in end-to-end training of continuous-output neural machine translation, where the trivial solution would be to set all vectors to the same value. In this work, we analyze the dynamics of representation collapse at different levels of discrete and continuous NMT transformers throughout training. We incorporate an existing regularization method based on angular dispersion and demonstrate empirically that it not only mitigates collapse but also improves translation quality. Furthermore, we show that quantized models exhibit similar collapse behavior and that the benefits of regularization are preserved even after quantization.
Anthology ID:
2026.findings-eacl.126
Volume:
Findings of the Association for Computational Linguistics: EACL 2026
Month:
March
Year:
2026
Address:
Rabat, Morocco
Editors:
Vera Demberg, Kentaro Inui, Lluís Marquez
Venue:
Findings
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
2420–2431
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URL:
https://preview.aclanthology.org/ingest-eacl/2026.findings-eacl.126/
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Bibkey:
Cite (ACL):
Evgeniia Tokarchuk, Maya K. Nachesa, Sergey Troshin, and Vlad Niculae. 2026. Representation Collapse in Machine Translation Through the Lens of Angular Dispersion. In Findings of the Association for Computational Linguistics: EACL 2026, pages 2420–2431, Rabat, Morocco. Association for Computational Linguistics.
Cite (Informal):
Representation Collapse in Machine Translation Through the Lens of Angular Dispersion (Tokarchuk et al., Findings 2026)
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