BioCoref: Benchmarking Biomedical Coreference Resolution with LLMs
Nourah M Salem, Elizabeth White, Michael Bada, Lawrence Hunter
TL;DR
This work tackles coreference resolution in biomedical texts by benchmarking generative LLM prompting strategies against a SpanBERT baseline on the CRAFT corpus. It defines four prompting configurations—local-only, local with reference context, abbreviation-aware, and entity-aware—and evaluates their ability to resolve pronouns, definite/indefinite noun phrases, and abbreviations. Results show that domain-grounded prompts can markedly improve recall and F1, with smaller LLaMA models (8B and 17B) frequently outperforming the 70B variant, highlighting the importance of prompt design over sheer model size. The study also demonstrates that structured inputs like abbreviation and entity dictionaries provide meaningful gains, while long-range context remains challenging, pointing to avenues for hybrid systems and external knowledge integration.
Abstract
Coreference resolution in biomedical texts presents unique challenges due to complex domain-specific terminology, high ambiguity in mention forms, and long-distance dependencies between coreferring expressions. In this work, we present a comprehensive evaluation of generative large language models (LLMs) for coreference resolution in the biomedical domain. Using the CRAFT corpus as our benchmark, we assess the LLMs' performance with four prompting experiments that vary in their use of local, contextual enrichment, and domain-specific cues such as abbreviations and entity dictionaries. We benchmark these approaches against a discriminative span-based encoder, SpanBERT, to compare the efficacy of generative versus discriminative methods. Our results demonstrate that while LLMs exhibit strong surface-level coreference capabilities, especially when supplemented with domain-grounding prompts, their performance remains sensitive to long-range context and mentions ambiguity. Notably, the LLaMA 8B and 17B models show superior precision and F1 scores under entity-augmented prompting, highlighting the potential of lightweight prompt engineering for enhancing LLM utility in biomedical NLP tasks.
