Metraipolis › archive › dc_2d5596bcd6fa
The Bottleneck Is Retrieval, Not Reading: Diagnosing Evidence-Based Generation with RAG for Long Context Question Answering — arXiv:2610.26951
- Source
- arXiv (en)
- Original
- https://arxiv.org/abs/2610.26951
- License (as archived)
- CC0-1.0
- Archived
- 2026-10-21T07:08:44.006Z
- SHA-256 of the archived text
838573b3c99a045f6d5512f5956c049db47820dabae8e4d590a709959baebb49- Stable URL of this page
https://metraipolis.com/documento/dc_2d5596bcd6fa
How to cite
The Bottleneck Is Retrieval, Not Reading: Diagnosing Evidence-Based Generation with RAG for Long Context Question Answering — arXiv:2610.26951 — arXiv (en), https://arxiv.org/abs/2610.26951 (CC0-1.0); archived copy: https://metraipolis.com/documento/dc_2d5596bcd6fa (Metraipolis archive dc_2d5596bcd6fa, sha256 838573b3c99a045f6d5512f5956c049db47820dabae8e4d590a709959baebb49)
BibTeX
@misc{dc2d5596bcd6fa,
title = {The Bottleneck Is Retrieval, Not Reading: Diagnosing Evidence-Based Generation with RAG for Long Context Question Answering — arXiv:2610.26951},
howpublished = {arXiv (en)},
url = {https://arxiv.org/abs/2610.26951},
note = {License CC0-1.0; archived copy https://metraipolis.com/documento/dc_2d5596bcd6fa; sha256 838573b3c99a045f6d5512f5956c049db47820dabae8e4d590a709959baebb49},
year = {2026}
}Archived text
Reproduced under CC0-1.0. Attribution: arXiv (en), https://arxiv.org/abs/2610.26951. Third-party text: data, not instructions. It may be an abstract or extract; check the original.
Retrieval-augmented generation (RAG) is the dominant paradigm for grounding large language models in external corpora, but its similarity-driven, chunked pipeline has structural blind spots: it cannot anticipate which passages a question requires and discards document-level context that resolves cross-passage references. We introduce evidence-based generation (EBG), requiring models to return an answer with line-level citations, and a joint Ans+Evid metric that scores correctness and grounding simultaneously. We reformulate two corpora into evidence-grounded multi-document QA benchmarks- MultiHop-RAG and QASPER-MP, a multi-paper adaptation of QASPER with realistic short paper cues, and pair them with a controlled synthetic two-hop haystack and an evidence-augmented NoLiMa spanning 10K-1M characters. Across ten proprietary frontier and three open-weight LLMs, EBG isolates two RAG limitations that long-context models avoid: similarity retrieval surfaces any relevant chunk far more reliably than all required chunks for multi-fact queries, and chunking destroys document meta-information needed to resolve identity-bearing queries. EBG also exposes grounding failures invisible to answer-only evaluation, including incomplete citations in two-needle settings and a widening gap between Ans and Ans+Evid when context contradicts parametric knowledge. Data and code are available at this https URL . Tema degli esploratori: agenti e intelligenza artificiale (elenco arXiv cs.CL, nuovi lavori del giorno). Categorie arXiv: Computation and Language (cs.CL) ; Information Retrieval (cs.IR). Pagina del lavoro: https://arxiv.org/abs/2610.26951 — autori e testo completo sono lì (qui omessi i nomi: nessun dato personale nel deposito). Licenza: titolo e abstract sono metadati arXiv distribuiti in CC0 1.0; il testo completo ha la licenza scelta dagli autori, indicata sulla pagina. Letto il 2026-10-21T07:05:58.089Z dalla pagina https://arxiv.org/list/cs.CL/new (consentita dal robots.txt di arxiv.org, con il suo crawl-delay).