Probing-RAG: Self-Probing to Guide Language Models in Selective Document Retrieval
Ingeol Baek, Hwan Chang, ByeongJeong Kim, Jimin Lee, Hwanhee Lee
Abstract
Retrieval-Augmented Generation (RAG) enhances language models by retrieving and incorporating relevant external knowledge. However, traditional retrieve-and-generate processes may not be optimized for real-world scenarios, where queries might require multiple retrieval steps or none at all. In this paper, we propose a Probing-RAG, which utilizes the hidden state representations from the intermediate layers of language models to adaptively determine the necessity of additional retrievals for a given query. By employing a pre-trained prober, Probing-RAG effectively captures the model’s internal cognition, enabling reliable decision-making about retrieving external documents. Experimental results across five open-domain QA datasets demonstrate that Probing-RAG outperforms previous methods while reducing the number of redundant retrieval steps.- Anthology ID:
- 2025.findings-naacl.181
- Volume:
- Findings of the Association for Computational Linguistics: NAACL 2025
- Month:
- April
- Year:
- 2025
- Address:
- Albuquerque, New Mexico
- Editors:
- Luis Chiruzzo, Alan Ritter, Lu Wang
- Venue:
- Findings
- SIG:
- Publisher:
- Association for Computational Linguistics
- Note:
- Pages:
- 3287–3304
- Language:
- URL:
- https://preview.aclanthology.org/Ingest-2025-COMPUTEL/2025.findings-naacl.181/
- DOI:
- Cite (ACL):
- Ingeol Baek, Hwan Chang, ByeongJeong Kim, Jimin Lee, and Hwanhee Lee. 2025. Probing-RAG: Self-Probing to Guide Language Models in Selective Document Retrieval. In Findings of the Association for Computational Linguistics: NAACL 2025, pages 3287–3304, Albuquerque, New Mexico. Association for Computational Linguistics.
- Cite (Informal):
- Probing-RAG: Self-Probing to Guide Language Models in Selective Document Retrieval (Baek et al., Findings 2025)
- PDF:
- https://preview.aclanthology.org/Ingest-2025-COMPUTEL/2025.findings-naacl.181.pdf