Do Generalisation Results Generalise?

Matteo Boglioni, Andrea Sgobbi, Gabriel Tavernini, Francesco Rita, Marius Mosbach, Tiago Pimentel


Abstract
A large language model’s (LLM’s) out-of-distribution (OOD) generalisation is crucial to its deployment. Previous work assessing LLMs’ generalisation performance, however, typically focuses on a single out-of-distribution dataset. This approach may fail to precisely evaluate the capabilities of the model, as the data shifts encountered during deployment are much more diverse. In this work, we investigate whether OOD generalisation results generalise. More specifically, we evaluate a model’s performance across multiple OOD testsets throughout a finetuning run; we then evaluate the partial correlation of performances across these testsets, regressing out in-domain performance. This allows us to assess how correlated are generalisation performances once in-domain performance is controlled for. Analysing OLMo, OPT and SmolLM, we observe no overarching trend in generalisation results: the existence of a positive or negative correlation between any two OOD testsets depends strongly on the specific choice of model analysed.
Anthology ID:
2026.findings-acl.1284
Volume:
Findings of the Association for Computational Linguistics: ACL 2026
Month:
July
Year:
2026
Address:
San Diego, California, United States
Editors:
Maria Liakata, Viviane P. Moreira, Jiajun Zhang, David Jurgens
Venue:
Findings
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
25763–25783
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URL:
https://preview.aclanthology.org/ingest-acl/2026.findings-acl.1284/
DOI:
Bibkey:
Cite (ACL):
Matteo Boglioni, Andrea Sgobbi, Gabriel Tavernini, Francesco Rita, Marius Mosbach, and Tiago Pimentel. 2026. Do Generalisation Results Generalise?. In Findings of the Association for Computational Linguistics: ACL 2026, pages 25763–25783, San Diego, California, United States. Association for Computational Linguistics.
Cite (Informal):
Do Generalisation Results Generalise? (Boglioni et al., Findings 2026)
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https://preview.aclanthology.org/ingest-acl/2026.findings-acl.1284.pdf
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