MemUse: Moving Memory Evaluation from Direct QA to Natural Integration in Long-Term Human-AI Conversation

Ryuichi Sumida, Koji Inoue, Tatsuya Kawahara


Abstract
Memory systems for conversational LLMs are conventionally evaluated by direct, fact-seeking questions about prior dialogue (Direct QA): can the model recall fact X from a prior conversation? We tested whether higher Direct QA accuracy correlates with higher user satisfaction in a four-month deployment involving 40 users, 1,872 sessions, and seven memory conditions. Existing-benchmark Direct QA accuracy varies from 19.7% to 70.1% across the seven conditions, but satisfaction does not change. We hypothesize that existing benchmarks and user satisfaction measure different capabilities: benchmarks measure elicited retrieval—recall when explicitly asked—whereas natural conversation requires detecting relevance and appropriately integrating prior context into a response. To examine this distinction, we introduce MemUse, a benchmark of real user-cued memory moments drawn from the deployment and evaluated using integration-aware judgments of natural conversational responses. Holding the model and context fixed, the same system that scores 78.8% on Direct QA references only 7.9% of those facts in conversation, revealing a 71-point retrieval–integration gap. Within a small observational subset of naturally occurring memory moments, successful Natural Integration is positively associated with user satisfaction, whereas Direct QA performance is not. We release the deployment corpus and MemUse together with the associated judgments and scoring prompts.
Anthology ID:
2026.emnlp-main.804
Volume:
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
EMNLP
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
18719–18749
Language:
URL:
https://aclanthology.org/2026.emnlp-main.804/
DOI:
Bibkey:
Cite (ACL):
Ryuichi Sumida, Koji Inoue, and Tatsuya Kawahara. 2026. MemUse: Moving Memory Evaluation from Direct QA to Natural Integration in Long-Term Human-AI Conversation. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 18719–18749, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
MemUse: Moving Memory Evaluation from Direct QA to Natural Integration in Long-Term Human-AI Conversation (Sumida et al., EMNLP 2026)
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PDF:
https://aclanthology.org/2026.emnlp-main.804.pdf