Beyond Ranking: Role-Specific Signals for Token-Budgeted SFT Data Selection

Haocheng Zhu, Tianqi Wang, Jun Suzuki


Abstract
Supervised fine-tuning (SFT) is a core stage in post-training general-purpose language models, but modern SFT training corpora are often large, heterogeneous mixtures, making data selection important under fixed token budgets. Simple ranking approaches can be informative yet insufficient: ranking alone does not determine how to allocate a fixed token budget across examples. We study the role-specific use of likelihood-derived signals for token-budgeted subset construction. An external instruction-tuned reference model computes response-side negative log-likelihood scores to rank training examples. We then combine this ranking with base model likelihood filtering to restrict the candidate region and response-side cosine filtering to reduce redundancy in the selected subset. In the OLMo fine-tuning setting studied here, ranking examples only by reference-model likelihood underperforms the random baseline, whereas the same ranking becomes more effective when combined with base model likelihood filtering and cosine-based redundancy control. Our results support viewing token-budgeted SFT data selection as a budget-allocation problem rather than only as an example-ranking problem.
Anthology ID:
2026.findings-emnlp.1956
Volume:
Findings of the Association for Computational Linguistics: EMNLP 2026
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
Findings
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
41717–41729
Language:
URL:
https://aclanthology.org/2026.findings-emnlp.1956/
DOI:
10.18653/2026.findings-emnlp.1956
Bibkey:
Cite (ACL):
Haocheng Zhu, Tianqi Wang, and Jun Suzuki. 2026. Beyond Ranking: Role-Specific Signals for Token-Budgeted SFT Data Selection. In Findings of the Association for Computational Linguistics: EMNLP 2026, pages 41717–41729, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Beyond Ranking: Role-Specific Signals for Token-Budgeted SFT Data Selection (Zhu et al., Findings 2026)
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PDF:
https://aclanthology.org/2026.findings-emnlp.1956.pdf