Litmus (Re)Agent: A Benchmark and Agentic System for Predictive Evaluation of Multilingual Models

Avni Mittal, Shanu Kumar, Sandipan Dandapat, Monojit Choudhury


Abstract
Multilingual deployment often requires estimating how well a model will perform on a task in a target language when direct benchmark results are unavailable and published evidence is incomplete. We study whether structured agentic reasoning can support this predictive multilingual evaluation task. We introduce a controlled benchmark of 1,500 questions spanning six tasks and five evidence scenarios. The benchmark separates accessible evidence from ground truth, enabling evaluation of systems that must infer missing results from incomplete literature evidence. We also present Litmus (Re)Agent, a DAG-orchestrated agentic system that decomposes queries into hypotheses, retrieves evidence, and synthesises predictions through feature-aware aggregation. Across six systems, Litmus (Re)Agent achieves the best overall performance, with the largest gains in transfer-heavy scenarios where direct evidence is weak or absent. These results show that structured agentic reasoning is a promising approach to multilingual performance estimation under incomplete evidence.
Anthology ID:
2026.emnlp-main.1766
Volume:
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
EMNLP
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
40255–40282
Language:
URL:
https://aclanthology.org/2026.emnlp-main.1766/
DOI:
Bibkey:
Cite (ACL):
Avni Mittal, Shanu Kumar, Sandipan Dandapat, and Monojit Choudhury. 2026. Litmus (Re)Agent: A Benchmark and Agentic System for Predictive Evaluation of Multilingual Models. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 40255–40282, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Litmus (Re)Agent: A Benchmark and Agentic System for Predictive Evaluation of Multilingual Models (Mittal et al., EMNLP 2026)
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PDF:
https://aclanthology.org/2026.emnlp-main.1766.pdf