From Instance Selection to Fixed-Pool Data Recipe Search for Supervised Fine-Tuning

Haodong Wu, Jiahao Zhang, Lijie Hu, Yongqi Zhang


Abstract
Supervised fine-tuning (SFT) data selection is commonly formulated as instance ranking: score each example and retain a top-k subset. However, effective SFT training subsets are often produced through ordered curation recipes, where filtering, mixing, and deduplication operators jointly shape the final data distribution. We formulate this problem as fixed-pool data recipe search: given a raw instruction pool and a library of grounded operators, the goal is to discover an executable recipe that constructs a high-quality selected subset under a limited budget of full SFT evaluations, without generating, rewriting, or augmenting training samples. We introduce AutoSelection, a two-layer solver that decouples fixed-pool materialization based on cached task-, data-, and model-side signals from expensive full evaluation, using warmup probes, realized subset states, local recipe edits, Gaussian-process-assisted ranking, and stagnation-triggered reseeding. Experiments on a 90K instruction pool show that AutoSelection achieves the strongest in-distribution reasoning average across three base models, outperforming full-data training, random recipe search, random top-k, and single-operator selectors. Additional held-out reasoning, instruction-following, graph-reasoning, search-stability, structural-ablation, and 1.5B-to-7B transfer results further show that recipe structure matters beyond individual selection operators. Code is available at https://github.com/w253/AutoSelection.
Anthology ID:
2026.emnlp-main.1877
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:
42785–42818
Language:
URL:
https://aclanthology.org/2026.emnlp-main.1877/
DOI:
Bibkey:
Cite (ACL):
Haodong Wu, Jiahao Zhang, Lijie Hu, and Yongqi Zhang. 2026. From Instance Selection to Fixed-Pool Data Recipe Search for Supervised Fine-Tuning. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 42785–42818, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
From Instance Selection to Fixed-Pool Data Recipe Search for Supervised Fine-Tuning (Wu et al., EMNLP 2026)
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PDF:
https://aclanthology.org/2026.emnlp-main.1877.pdf