Investigating and Enhancing Concept Induction in LLMs: A Prototype-based Property-augmented Approach

Mingyang Lyu, Bin Zhang, Chenlong Bao, Jin-Tao Tang, Shasha Li, Ting Wang


Abstract
Concept induction, which infers appropriate abstract categories from concrete instances, is both a core ontology engineering task and a testbed for LLM semantic abstraction. Although LLMs offer broad knowledge and reasoning that may ease expert-driven ontology construction, prior work shows that knowledge deficiencies still limit them in specialized domains, while systematic evaluation of their induction failures remains lacking. To address this gap, we propose a familiarity-controlled evaluation framework that uses knowledge probing to separate item familiarity from concept induction ability. The evaluation reveals a systematic tendency to induce overly general concepts: LLMs often produce semantically correct but overly broad labels, and direct property augmentation improves performance without resolving this granularity mismatch. We further propose PPACI, an ontology-prior-guided approach that builds concept prototypes by integrating concept definitions with member item properties. For each query group, PPACI uses item properties to retrieve local item-level and global group-level candidate concepts as induction anchors. Experiments across multiple LLMs show that PPACI reduces overly general predictions by 17–28 percentage points while maintaining competitive induction quality. Our code and data are publicly available at https://github.com/Orchideous77/PPACI.
Anthology ID:
2026.emnlp-main.225
Volume:
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
EMNLP
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
5203–5219
Language:
URL:
https://aclanthology.org/2026.emnlp-main.225/
DOI:
Bibkey:
Cite (ACL):
Mingyang Lyu, Bin Zhang, Chenlong Bao, Jin-Tao Tang, Shasha Li, and Ting Wang. 2026. Investigating and Enhancing Concept Induction in LLMs: A Prototype-based Property-augmented Approach. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 5203–5219, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Investigating and Enhancing Concept Induction in LLMs: A Prototype-based Property-augmented Approach (Lyu et al., EMNLP 2026)
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PDF:
https://aclanthology.org/2026.emnlp-main.225.pdf