Enabling Trait-based Personality Simulation in Conversational LLM Agents: Case Study of Customer Assistance in French

Ahmed Njifenjou, Virgile Sucal, Bassam Jabaian, Fabrice Lefèvre


Abstract
Among the numerous models developed to represent the multifaceted complexity of human personality, particularly in psychology, the Big Five (commonly referred to as ‘OCEAN’, an acronym of its five traits) stands out as a widely used framework. Although personalized chatbots have incorporated this model, existing approaches, such as focusing on individual traits or binary combinations, may not capture the full diversity of human personality. In this study, we propose a five-dimensional vector representation, where each axis corresponds to the degree of presence of an OCEAN trait on a continuous scale from 0 to 1. This representation is designed to enable greater versatility in modeling personality. Application to customer assistance scenarios in French demonstrates that, based on humans-bots as well as bots-bots conversations, assigned personality vectors are distinguishable by both humans and LLMs acting as judges. Both of their subjective evaluations also confirm the measurable impacts of the assigned personality on user experience, agent efficiency, and conversation quality.
Anthology ID:
2025.iwsds-1.32
Volume:
Proceedings of the 15th International Workshop on Spoken Dialogue Systems Technology
Month:
May
Year:
2025
Address:
Bilbao, Spain
Editors:
Maria Ines Torres, Yuki Matsuda, Zoraida Callejas, Arantza del Pozo, Luis Fernando D'Haro
Venues:
IWSDS | WS
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
299–308
Language:
URL:
https://preview.aclanthology.org/fix-sig-urls/2025.iwsds-1.32/
DOI:
Bibkey:
Cite (ACL):
Ahmed Njifenjou, Virgile Sucal, Bassam Jabaian, and Fabrice Lefèvre. 2025. Enabling Trait-based Personality Simulation in Conversational LLM Agents: Case Study of Customer Assistance in French. In Proceedings of the 15th International Workshop on Spoken Dialogue Systems Technology, pages 299–308, Bilbao, Spain. Association for Computational Linguistics.
Cite (Informal):
Enabling Trait-based Personality Simulation in Conversational LLM Agents: Case Study of Customer Assistance in French (Njifenjou et al., IWSDS 2025)
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PDF:
https://preview.aclanthology.org/fix-sig-urls/2025.iwsds-1.32.pdf