ChapsVision (CHV) at WMT 2026 CreoleMT: Shifting Creole MT from Train-Time to Test-Time Compute for Haitian Creole

Louis Jourdain, Aurélie Pradelles, Nasredine Semmar


Abstract
We describe a training-free system for the WMT26 Creole MT shared task, targeting Haitian Creole in four directions (eng↔hat, fra↔hat). Rather than fine-tune, we wrap a sin- gle fixed 8B instruction model (qwen3-8b) in a language-agnostic harness that retrieves lexi- cal, parallel-data and grammatical evidence and injects it directly into the translation prompt. On FLORES+ devtest the harness lifts the base model by up to +14 chrF++ and clears the shared task’s primary baseline in all four di- rections, though a purpose-fine-tuned system (kreyòl-MT) and frontier LLM still lead the mean. On the task’s blind test set that ordering reverses: we finish below both baselines, while the harness gain itself holds, staying large into Creole and small out of it. Two findings frame the paper. First, injected knowledge behaves as a reasoning equalizer: the same evidence that lifts a weak open model leaves a strong frontier model flat, so grounding substitutes for a capa- bility the model lacks rather than amplifying one it has. Second, how evidence is delivered dominates: forcing it into the prompt beats let- ting the model self-serve the same tools in an agentic (ReAct) loop, which costs about 6× the tokens.
Anthology ID:
2026.wmt-main.187
Volume:
Proceedings of the Eleventh Conference on Machine Translation
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Barry Haddow, Tom Kocmi, Philipp Koehn, Christof Monz
Venues:
WMT | WS
SIG:
SIGMT
Publisher:
Association for Computational Linguistics
Note:
Pages:
2421–2447
Language:
URL:
https://aclanthology.org/2026.wmt-main.187/
DOI:
Bibkey:
Cite (ACL):
Louis Jourdain, Aurélie Pradelles, and Nasredine Semmar. 2026. ChapsVision (CHV) at WMT 2026 CreoleMT: Shifting Creole MT from Train-Time to Test-Time Compute for Haitian Creole. In Proceedings of the Eleventh Conference on Machine Translation, pages 2421–2447, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
ChapsVision (CHV) at WMT 2026 CreoleMT: Shifting Creole MT from Train-Time to Test-Time Compute for Haitian Creole (Jourdain et al., WMT 2026)
Copy Citation:
PDF:
https://aclanthology.org/2026.wmt-main.187.pdf