Diagnosable ColBERT: Debugging Late-Interaction Retrieval Models Using a Learned Latent Space as Reference

François Remy


Abstract
Reliable biomedical and clinical retrieval requires more than strong ranking performance: it requires a practical way to find systematic model failures and curate the training evidence needed to correct them. Late-interaction models such as ColBERT provide a first solution thanks to the interpretable token-level interaction scores they expose between document and query tokens. Yet this interpretability is shallow: it explains a particular document–query pairwise score, but does not reveal whether the model has learned a clinical concept in a stable, reusable, and context-sensitive way across diverse expressions. As a result, these scores provide limited support for diagnosing misunderstandings, identifying irreasonably distant biomedical concepts, or deciding what additional data or feedback is needed to address this. In this short position paper, we propose Diagnosable ColBERT, a framework that aligns ColBERT token embeddings to a reference latent space grounded in clinical knowledge and expert-provided conceptual similarity constraints. This alignment turns document encodings into inspectable evidence of what the model appears to understand, enabling more direct error diagnosis and more principled data curation without relying on large batteries of diagnostic queries.
Anthology ID:
2026.bionlp-1.58
Volume:
BioNLP 2026
Month:
July
Year:
2026
Address:
San Diego, California
Editors:
Dina Demner-Fushman, Sophia Ananiadou, Kirk Roberts, Junichi Tsujii
Venues:
BioNLP | WS
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
713–717
Language:
URL:
https://preview.aclanthology.org/ingest-acl-workshops/2026.bionlp-1.58/
DOI:
Bibkey:
Cite (ACL):
François Remy. 2026. Diagnosable ColBERT: Debugging Late-Interaction Retrieval Models Using a Learned Latent Space as Reference. In BioNLP 2026, pages 713–717, San Diego, California. Association for Computational Linguistics.
Cite (Informal):
Diagnosable ColBERT: Debugging Late-Interaction Retrieval Models Using a Learned Latent Space as Reference (Remy, BioNLP 2026)
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PDF:
https://preview.aclanthology.org/ingest-acl-workshops/2026.bionlp-1.58.pdf