Evaluating the Long-Term Memory of Large Language Models

Zixi Jia, Qinghua Liu, Hexiao Li, Yuyan Chen, Jiqiang Liu


Abstract
In applications such as dialogue systems, personalized recommendations, and personal assistants, large language models (LLMs) need to retain and utilize historical information over the long term to provide more accurate and consistent responses. Although long-term memory capability is crucial, recent studies have not thoroughly investigated the memory performance of large language models in long-term tasks. To address this gap, we introduce the Long-term Chronological Conversations (LOCCO) dataset and conduct a quantitative evaluation of the long-term memory capabilities of large language models. Experimental results demonstrate that large language models can retain past interaction information to a certain extent, but their memory decays over time. While rehearsal strategies can enhance memory persistence, excessive rehearsal is not an effective memory strategy for large models, unlike in smaller models. Additionally, the models exhibit memory preferences across different categories of information. Our study not only provides a new framework and dataset for evaluating the long-term memory capabilities of large language models but also offers important references for future enhancements of their memory persistence.
Anthology ID:
2025.findings-acl.1014
Volume:
Findings of the Association for Computational Linguistics: ACL 2025
Month:
July
Year:
2025
Address:
Vienna, Austria
Editors:
Wanxiang Che, Joyce Nabende, Ekaterina Shutova, Mohammad Taher Pilehvar
Venues:
Findings | WS
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
19759–19777
Language:
URL:
https://preview.aclanthology.org/ingestion-acl-25/2025.findings-acl.1014/
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Bibkey:
Cite (ACL):
Zixi Jia, Qinghua Liu, Hexiao Li, Yuyan Chen, and Jiqiang Liu. 2025. Evaluating the Long-Term Memory of Large Language Models. In Findings of the Association for Computational Linguistics: ACL 2025, pages 19759–19777, Vienna, Austria. Association for Computational Linguistics.
Cite (Informal):
Evaluating the Long-Term Memory of Large Language Models (Jia et al., Findings 2025)
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https://preview.aclanthology.org/ingestion-acl-25/2025.findings-acl.1014.pdf