OntologyBench: Can Dense Retrieval Satisfy Structured Biomedical Constraints?

Xiao Yu Cindy Zhang, Wyeth Wasserman, Jian Zhu


Abstract
We introduce OntologyBench, a tiered biomedical retrieval benchmark comprising 471,854 training and 125,744 evaluation query–document relevance pairs across concept grounding, relational retrieval, and compositional phenotype-based retrieval.

Although these tasks can be tractable using ontology-aware reference methods, across task tiers, embedding performance is generally lower on relational and compositional tasks than on concept-grounding tasks. Fine-tuning on ontology-derived supervision improves performance on several relational and compositional tasks, whereas the evaluated reranking and LLM-based candidate-scoring methods provide little or no end-to-end improvement. Errors frequently reflect diseases matching only subsets of the phenotype evidence.

These findings indicate that the evaluated embedding and reranking configurations do not reliably recover the compatibility encoded by the selected ontology relations and phenotype combinations and motivate retrieval systems that better integrate learned representations with structured biomedical knowledge.
Anthology ID:
2026.emnlp-main.595
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:
13707–13725
Language:
URL:
https://aclanthology.org/2026.emnlp-main.595/
DOI:
Bibkey:
Cite (ACL):
Xiao Yu Cindy Zhang, Wyeth Wasserman, and Jian Zhu. 2026. OntologyBench: Can Dense Retrieval Satisfy Structured Biomedical Constraints?. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 13707–13725, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
OntologyBench: Can Dense Retrieval Satisfy Structured Biomedical Constraints? (Zhang et al., EMNLP 2026)
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https://aclanthology.org/2026.emnlp-main.595.pdf