The Cost of Decomposition: Trade-Offs in Long-Context Aspect-Based Scientific Summarization

Pierre Achkar, Elena Senger, Tim Gollub, Martin Potthast, Yuri Campbell


Abstract
Aspect-based scientific summarization produces a focused summary of a long document for a given aspect (e.g., Approach, Methods). Prior work decomposes the task, assuming a model can neither attend over the full document nor resolve aspect complexity in one pass. We revisit both assumptions now that compact yet capable language models handle long contexts natively. Across three datasets and two primary open long-context models, decomposition provides no reliable quality advantage over direct full-document prompting. With the main 9B model, zero-shot is strongest on aggregate lexical, semantic, and claim-recall/F1 metrics; under the 7B robustness model, simple decomposed variants occasionally edge zero-shot, but gains are small and inconsistent. On these primary models, the multi-role agentic pipeline is never best in aggregate and incurs substantially higher token cost, whereas RAG uses roughly one seventh of zero-shot’s tokens but delivers lower, less consistent quality. We characterize where added complexity loses, quantify the cost–quality trade-off, and distill practical deployment guidance. Code is available on GitHub.
Anthology ID:
2026.emnlp-industry.95
Volume:
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing: Industry Track
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Pepa Atanasova, Gholamreza Haffari, Minghan Wang
Venue:
EMNLP
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
1613–1636
Language:
URL:
https://aclanthology.org/2026.emnlp-industry.95/
DOI:
Bibkey:
Cite (ACL):
Pierre Achkar, Elena Senger, Tim Gollub, Martin Potthast, and Yuri Campbell. 2026. The Cost of Decomposition: Trade-Offs in Long-Context Aspect-Based Scientific Summarization. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing: Industry Track, pages 1613–1636, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
The Cost of Decomposition: Trade-Offs in Long-Context Aspect-Based Scientific Summarization (Achkar et al., EMNLP 2026)
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PDF:
https://aclanthology.org/2026.emnlp-industry.95.pdf