@inproceedings{wang-etal-2026-memories,
title = "When Do Memories Break? Chain-of-Stage Diagnosis for {LLM} Memory Systems",
author = "Wang, Chenchen and
Fu, Yujie and
Zheng, Zhiyu and
Qin, Shiyu and
Cao, Zhao and
Liu, Zheng",
editor = "Lee, Hung-Yi and
Dev, Sunipa and
Li, Jessy and
Elliott, Desmond",
booktitle = "Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing",
month = oct,
year = "2026",
address = "Budapest, Hungary",
publisher = "Association for Computational Linguistics",
url = "https://aclanthology.org/2026.emnlp-main.1042/",
pages = "23931--23951",
ISBN = "979-8-89176-459-0",
abstract = "Memory-augmented Large Language Models frequently fail to maintain long-term context due to opaque evaluation mechanisms that obscure the root causes of failure. To address this, we introduce MemEval, a stage-wise attribution framework that approximates where failures arise across extraction, update, retrieval, and utilization. On LoCoMo, our automated meta-evaluator achieves 81.62{\%} stage-level consistency with human judgment. Our analysis reveals three critical findings: (1) Extraction is the universal bottleneck, causing information loss at the entry point; (2) Retrieval and utilization failures become prominent in complex reasoning and temporal tasks, even when relevant memories are stored or retrieved; and (3) Scaling base model capacity does not guarantee more reliable memory behavior, as higher-capacity backbones may introduce early-stage misalignment that propagates downstream. MemEval provides a practical diagnostic aid for trend-level, stage-aware analysis of memory systems. Code is available at: https://anonymous.4open.science/r/MemEval-8D41."
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<abstract>Memory-augmented Large Language Models frequently fail to maintain long-term context due to opaque evaluation mechanisms that obscure the root causes of failure. To address this, we introduce MemEval, a stage-wise attribution framework that approximates where failures arise across extraction, update, retrieval, and utilization. On LoCoMo, our automated meta-evaluator achieves 81.62% stage-level consistency with human judgment. Our analysis reveals three critical findings: (1) Extraction is the universal bottleneck, causing information loss at the entry point; (2) Retrieval and utilization failures become prominent in complex reasoning and temporal tasks, even when relevant memories are stored or retrieved; and (3) Scaling base model capacity does not guarantee more reliable memory behavior, as higher-capacity backbones may introduce early-stage misalignment that propagates downstream. MemEval provides a practical diagnostic aid for trend-level, stage-aware analysis of memory systems. Code is available at: https://anonymous.4open.science/r/MemEval-8D41.</abstract>
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%0 Conference Proceedings
%T When Do Memories Break? Chain-of-Stage Diagnosis for LLM Memory Systems
%A Wang, Chenchen
%A Fu, Yujie
%A Zheng, Zhiyu
%A Qin, Shiyu
%A Cao, Zhao
%A Liu, Zheng
%Y Lee, Hung-Yi
%Y Dev, Sunipa
%Y Li, Jessy
%Y Elliott, Desmond
%S Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
%D 2026
%8 October
%I Association for Computational Linguistics
%C Budapest, Hungary
%@ 979-8-89176-459-0
%F wang-etal-2026-memories
%X Memory-augmented Large Language Models frequently fail to maintain long-term context due to opaque evaluation mechanisms that obscure the root causes of failure. To address this, we introduce MemEval, a stage-wise attribution framework that approximates where failures arise across extraction, update, retrieval, and utilization. On LoCoMo, our automated meta-evaluator achieves 81.62% stage-level consistency with human judgment. Our analysis reveals three critical findings: (1) Extraction is the universal bottleneck, causing information loss at the entry point; (2) Retrieval and utilization failures become prominent in complex reasoning and temporal tasks, even when relevant memories are stored or retrieved; and (3) Scaling base model capacity does not guarantee more reliable memory behavior, as higher-capacity backbones may introduce early-stage misalignment that propagates downstream. MemEval provides a practical diagnostic aid for trend-level, stage-aware analysis of memory systems. Code is available at: https://anonymous.4open.science/r/MemEval-8D41.
%U https://aclanthology.org/2026.emnlp-main.1042/
%P 23931-23951
Markdown (Informal)
[When Do Memories Break? Chain-of-Stage Diagnosis for LLM Memory Systems](https://aclanthology.org/2026.emnlp-main.1042/) (Wang et al., EMNLP 2026)
ACL