User Memory Reasoning for Conversational Recommendation

Hu Xu, Seungwhan Moon, Honglei Liu, Bing Liu, Pararth Shah, Bing Liu, Philip Yu


Abstract
We study an end-to-end approach for conversational recommendation that dynamically manages and reasons over users’ past (offline) preferences and current (online) requests through a structured and cumulative user memory knowledge graph. This formulation extends existing state tracking beyond the boundary of a single dialog to user state tracking (UST). For this study, we create a new Memory Graph (MG) <-> Conversational Recommendation parallel corpus called MGConvRex with 7K+ human-to-human role-playing dialogs, grounded on a large-scale user memory bootstrapped from real-world user scenarios. MGConvRex captures human-level reasoning over user memory and has disjoint training/testing sets of users for zero-shot (cold-start) reasoning for recommendation. We propose a simple yet expandable formulation for constructing and updating the MG, and an end-to-end graph-based reasoning model that updates MG from unstructured utterances and predicts optimal dialog policies (eg recommendation) based on updated MG. The prediction of our proposed model inherits the graph structure, providing a natural way to explain policies. Experiments are conducted for both offline metrics and online simulation, showing competitive results.
Anthology ID:
2020.coling-main.463
Volume:
Proceedings of the 28th International Conference on Computational Linguistics
Month:
December
Year:
2020
Address:
Barcelona, Spain (Online)
Editors:
Donia Scott, Nuria Bel, Chengqing Zong
Venue:
COLING
SIG:
Publisher:
International Committee on Computational Linguistics
Note:
Pages:
5288–5308
Language:
URL:
https://aclanthology.org/2020.coling-main.463
DOI:
10.18653/v1/2020.coling-main.463
Bibkey:
Cite (ACL):
Hu Xu, Seungwhan Moon, Honglei Liu, Bing Liu, Pararth Shah, Bing Liu, and Philip Yu. 2020. User Memory Reasoning for Conversational Recommendation. In Proceedings of the 28th International Conference on Computational Linguistics, pages 5288–5308, Barcelona, Spain (Online). International Committee on Computational Linguistics.
Cite (Informal):
User Memory Reasoning for Conversational Recommendation (Xu et al., COLING 2020)
Copy Citation:
PDF:
https://aclanthology.org/2020.coling-main.463.pdf