Memorization or Extraction? Auditing LLM-Based Recovery of Scientific Assumptions

Suan Lee, JaeSeong Kim


Abstract
We audit whether benchmarks for LLM-based recovery of scientific assumptions measure corpus-grounded extraction or pretraining memorization. Using author-defined targets for 10 historical AI breakthroughs (frozen 4-case protocol plus 6 post-hoc stress cases) and a "field-wide paradigmatic assumption" prompt, GPT-4o’s top-10 extractions cover the target in 6/10 cases under a generous any-of-top-K criterion—an upper bound that a 10-rater study corroborates for only ∼0.19 of sampled top-ranked pairs (human–rule 𝜅=0.70, 𝛼=0.634). Controlled stress tests structure the diagnosis: a no-corpus control (field name only) still scores 4/4 on the primary shifts (memorization dominates), while a wrong-corpus control collapses to 0/12 across all 4×3 cross-pairings (corpus can be causally read); a five-LLM canonical sweep (GPT-4o 4/4, Qwen 2/4, Claude 1/4, Llama-3.1 1/4, Mistral 0/4) shows the gap is model-specific rather than closed-vs-open, with format compliance a major but not fully isolable contributor; a Min-K% Prob cross-check actually mis-ranks synthetic non-members as more contaminated than real pre-shift papers, motivating the behavioral framing; and synthetic/niche controls are mixed (causal in 1 of 3 synthetic scenarios, one shows corpus harm). We release an audit kit — five factorable controls (no-corpus, wrong-corpus, pair-level precision, ≥2-LLM, multi-seed; ∼$15) — as a reusable benchmark-validity probe, with all artifacts released.
Anthology ID:
2026.aacl-long.141
Volume:
Proceedings of the 15th International Joint Conference on Natural Language Processing and the 5th Conference of the Asia-Pacific Chapter of the Association for Computational Linguistics (Volume 1: Long Papers)
Month:
November
Year:
2026
Address:
Hengqin, China
Editors:
Yue Zhang, Ruifeng Xu, Ayu Purwarianti, Tong Rong, Jun Suzuki
Venues:
AACL | IJCNLP
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
3081–3102
Language:
URL:
https://aclanthology.org/2026.aacl-long.141/
DOI:
Bibkey:
Cite (ACL):
Suan Lee and JaeSeong Kim. 2026. Memorization or Extraction? Auditing LLM-Based Recovery of Scientific Assumptions. In Proceedings of the 15th International Joint Conference on Natural Language Processing and the 5th Conference of the Asia-Pacific Chapter of the Association for Computational Linguistics (Volume 1: Long Papers), pages 3081–3102, Hengqin, China. Association for Computational Linguistics.
Cite (Informal):
Memorization or Extraction? Auditing LLM-Based Recovery of Scientific Assumptions (Lee & Kim, AACL-IJCNLP 2026)
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PDF:
https://aclanthology.org/2026.aacl-long.141.pdf