Beyond Sample-Level Feedback: Using Reference-Level Feedback to Guide Data Synthesis

Shuhaib Mehri, Xiusi Chen, Heng Ji, Dilek Hakkani-Tür


Abstract
High-quality instruction-tuning data is crucial for developing Large Language Models (LLMs) that can effectively navigate real-world tasks and follow human instructions. While synthetic data generation offers a scalable approach for creating such datasets, it imposes a quality ceiling where models trained on the data cannot outperform the LLM generating it. To overcome this limitation, we introduce Reference-Level Feedback, a paradigm that extracts desirable characteristics from carefully curated reference samples to guide the synthesis of higher-quality instruction-response pairs. Using this approach, we synthesize REFED, a dataset of 10K instruction-response pairs. Fine-tuning Llama-3.1-8B-Instruct and Mistral-7B-Instruct on REFED demonstrate state-of-the-art performance among similarly sized models, notably reaching a 43.96% length-controlled win-rate on AlpacaEval 2.0. Extensive experiments demonstrate that Reference-Level Feedback consistently outperforms traditional sample-level feedback methods, generalizes across model architectures, and produces high-quality and diverse data at low cost.
Anthology ID:
2026.eacl-long.7
Volume:
Proceedings of the 19th Conference of the European Chapter of the Association for Computational Linguistics (Volume 1: Long Papers)
Month:
March
Year:
2026
Address:
Rabat, Morocco
Editors:
Vera Demberg, Kentaro Inui, Lluís Marquez
Venue:
EACL
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
141–164
Language:
URL:
https://preview.aclanthology.org/ingest-eacl/2026.eacl-long.7/
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Bibkey:
Cite (ACL):
Shuhaib Mehri, Xiusi Chen, Heng Ji, and Dilek Hakkani-Tür. 2026. Beyond Sample-Level Feedback: Using Reference-Level Feedback to Guide Data Synthesis. In Proceedings of the 19th Conference of the European Chapter of the Association for Computational Linguistics (Volume 1: Long Papers), pages 141–164, Rabat, Morocco. Association for Computational Linguistics.
Cite (Informal):
Beyond Sample-Level Feedback: Using Reference-Level Feedback to Guide Data Synthesis (Mehri et al., EACL 2026)
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PDF:
https://preview.aclanthology.org/ingest-eacl/2026.eacl-long.7.pdf