IdentifyMe: A Challenging Long-Context Mention Resolution Benchmark for LLMs
Kawshik Manikantan, Makarand Tapaswi, Vineet Gandhi, Shubham Toshniwal
Abstract
Recent evaluations of LLMs on coreference resolution have revealed that traditional output formats and evaluation metrics do not fully capture the models’ referential understanding. To address this, we introduce IdentifyMe, a new benchmark for mention resolution presented in a multiple-choice question (MCQ) format, commonly used for evaluating LLMs. IdentifyMe features long narratives and employs heuristics to exclude easily identifiable mentions, creating a more challenging task. The benchmark also consists of a curated mixture of different mention types and corresponding entities, allowing for a fine-grained model performance analysis. We evaluate both closed- and open-source LLMs on IdentifyMe and observe a significant performance gap (20-30%) between the state-of-the-art sub-10B open models vs. closed ones. We observe that pronominal mentions, which have limited surface information, are typically harder for models to resolve than nominal mentions. Additionally, we find that LLMs often confuse entities when their mentions overlap in nested structures. The highest scoring model, GPT-4o, achieves 81.9% accuracy, highlighting the strong referential capabilities of state-of-the-art LLMs while also indicating room for further improvement.- Anthology ID:
- 2025.naacl-short.64
- Volume:
- Proceedings of the 2025 Conference of the Nations of the Americas Chapter of the Association for Computational Linguistics: Human Language Technologies (Volume 2: Short Papers)
- Month:
- April
- Year:
- 2025
- Address:
- Albuquerque, New Mexico
- Editors:
- Luis Chiruzzo, Alan Ritter, Lu Wang
- Venue:
- NAACL
- SIG:
- Publisher:
- Association for Computational Linguistics
- Note:
- Pages:
- 768–777
- Language:
- URL:
- https://preview.aclanthology.org/moar-dois/2025.naacl-short.64/
- DOI:
- 10.18653/v1/2025.naacl-short.64
- Cite (ACL):
- Kawshik Manikantan, Makarand Tapaswi, Vineet Gandhi, and Shubham Toshniwal. 2025. IdentifyMe: A Challenging Long-Context Mention Resolution Benchmark for LLMs. In Proceedings of the 2025 Conference of the Nations of the Americas Chapter of the Association for Computational Linguistics: Human Language Technologies (Volume 2: Short Papers), pages 768–777, Albuquerque, New Mexico. Association for Computational Linguistics.
- Cite (Informal):
- IdentifyMe: A Challenging Long-Context Mention Resolution Benchmark for LLMs (Manikantan et al., NAACL 2025)
- PDF:
- https://preview.aclanthology.org/moar-dois/2025.naacl-short.64.pdf