@inproceedings{papacek-schmidtova-2026-cuni,
title = "{CUNI}-{UFAL} at {WMT}26 Multilingual Instruction Shared Task",
author = "Pap{\'a}{\v{c}}ek, Ale{\v{s}} Manuel and
Schmidtova, Patricia",
editor = "Haddow, Barry and
Kocmi, Tom and
Koehn, Philipp and
Monz, Christof",
booktitle = "Proceedings of the Eleventh Conference on Machine Translation",
month = oct,
year = "2026",
address = "Budapest, Hungary",
publisher = "Association for Computational Linguistics",
url = "https://aclanthology.org/2026.wmt-main.130/",
pages = "1949--1958",
ISBN = "979-8-89176-474-3",
abstract = "We describe our submission to the WMT26 Multilingual Instruction Shared Task, which evaluates sub-10B-parameter models on multilingual question answering, open-ended generation, and cross-lingual summarization. We compare four open-weight models and vary the system prompt, reasoning mode, and decoding parameters. On our development set, the tested prompt and reasoning changes have a larger effect on LLM-judge scores than the difference between the two finalist models in their best settings. Gemma 4 E4B obtains the highest overall judge score, whereas Qwen 3.5 9B follows hard constraints more reliably on our internal benchmark. We therefore submit Qwen as our primary system and Gemma as a secondary system. We also introduce a 1,283-example diagnostic benchmark for grounded QA, constrained generation, and abstract writing from ACL papers in 24 languages. Using it for QLoRA fine-tuning does not work in our setup, it lowers validation loss but does not improve quality under our LLM judge. In the official automatic evaluation, our Gemma system ranks first overall and our Qwen system second; Qwen wins QA-context, while Gemma wins QA-OEG and places second in summarization."
}<?xml version="1.0" encoding="UTF-8"?>
<modsCollection xmlns="http://www.loc.gov/mods/v3">
<mods ID="papacek-schmidtova-2026-cuni">
<titleInfo>
<title>CUNI-UFAL at WMT26 Multilingual Instruction Shared Task</title>
</titleInfo>
<name type="personal">
<namePart type="given">Aleš</namePart>
<namePart type="given">Manuel</namePart>
<namePart type="family">Papáček</namePart>
<role>
<roleTerm authority="marcrelator" type="text">author</roleTerm>
</role>
</name>
<name type="personal">
<namePart type="given">Patricia</namePart>
<namePart type="family">Schmidtova</namePart>
<role>
<roleTerm authority="marcrelator" type="text">author</roleTerm>
</role>
</name>
<originInfo>
<dateIssued>2026-10</dateIssued>
</originInfo>
<typeOfResource>text</typeOfResource>
<relatedItem type="host">
<titleInfo>
<title>Proceedings of the Eleventh Conference on Machine Translation</title>
</titleInfo>
<name type="personal">
<namePart type="given">Barry</namePart>
<namePart type="family">Haddow</namePart>
<role>
<roleTerm authority="marcrelator" type="text">editor</roleTerm>
</role>
</name>
<name type="personal">
<namePart type="given">Tom</namePart>
<namePart type="family">Kocmi</namePart>
<role>
<roleTerm authority="marcrelator" type="text">editor</roleTerm>
</role>
</name>
<name type="personal">
<namePart type="given">Philipp</namePart>
<namePart type="family">Koehn</namePart>
<role>
<roleTerm authority="marcrelator" type="text">editor</roleTerm>
</role>
</name>
<name type="personal">
<namePart type="given">Christof</namePart>
<namePart type="family">Monz</namePart>
<role>
<roleTerm authority="marcrelator" type="text">editor</roleTerm>
</role>
</name>
<originInfo>
<publisher>Association for Computational Linguistics</publisher>
<place>
<placeTerm type="text">Budapest, Hungary</placeTerm>
</place>
</originInfo>
<genre authority="marcgt">conference publication</genre>
<identifier type="isbn">979-8-89176-474-3</identifier>
</relatedItem>
<abstract>We describe our submission to the WMT26 Multilingual Instruction Shared Task, which evaluates sub-10B-parameter models on multilingual question answering, open-ended generation, and cross-lingual summarization. We compare four open-weight models and vary the system prompt, reasoning mode, and decoding parameters. On our development set, the tested prompt and reasoning changes have a larger effect on LLM-judge scores than the difference between the two finalist models in their best settings. Gemma 4 E4B obtains the highest overall judge score, whereas Qwen 3.5 9B follows hard constraints more reliably on our internal benchmark. We therefore submit Qwen as our primary system and Gemma as a secondary system. We also introduce a 1,283-example diagnostic benchmark for grounded QA, constrained generation, and abstract writing from ACL papers in 24 languages. Using it for QLoRA fine-tuning does not work in our setup, it lowers validation loss but does not improve quality under our LLM judge. In the official automatic evaluation, our Gemma system ranks first overall and our Qwen system second; Qwen wins QA-context, while Gemma wins QA-OEG and places second in summarization.</abstract>
<identifier type="citekey">papacek-schmidtova-2026-cuni</identifier>
<location>
<url>https://aclanthology.org/2026.wmt-main.130/</url>
</location>
<part>
<date>2026-10</date>
<extent unit="page">
<start>1949</start>
<end>1958</end>
</extent>
</part>
</mods>
</modsCollection>
%0 Conference Proceedings
%T CUNI-UFAL at WMT26 Multilingual Instruction Shared Task
%A Papáček, Aleš Manuel
%A Schmidtova, Patricia
%Y Haddow, Barry
%Y Kocmi, Tom
%Y Koehn, Philipp
%Y Monz, Christof
%S Proceedings of the Eleventh Conference on Machine Translation
%D 2026
%8 October
%I Association for Computational Linguistics
%C Budapest, Hungary
%@ 979-8-89176-474-3
%F papacek-schmidtova-2026-cuni
%X We describe our submission to the WMT26 Multilingual Instruction Shared Task, which evaluates sub-10B-parameter models on multilingual question answering, open-ended generation, and cross-lingual summarization. We compare four open-weight models and vary the system prompt, reasoning mode, and decoding parameters. On our development set, the tested prompt and reasoning changes have a larger effect on LLM-judge scores than the difference between the two finalist models in their best settings. Gemma 4 E4B obtains the highest overall judge score, whereas Qwen 3.5 9B follows hard constraints more reliably on our internal benchmark. We therefore submit Qwen as our primary system and Gemma as a secondary system. We also introduce a 1,283-example diagnostic benchmark for grounded QA, constrained generation, and abstract writing from ACL papers in 24 languages. Using it for QLoRA fine-tuning does not work in our setup, it lowers validation loss but does not improve quality under our LLM judge. In the official automatic evaluation, our Gemma system ranks first overall and our Qwen system second; Qwen wins QA-context, while Gemma wins QA-OEG and places second in summarization.
%U https://aclanthology.org/2026.wmt-main.130/
%P 1949-1958
Markdown (Informal)
[CUNI-UFAL at WMT26 Multilingual Instruction Shared Task](https://aclanthology.org/2026.wmt-main.130/) (Papáček & Schmidtova, WMT 2026)
ACL