Goal Alignment in LLM-Based User Simulators for Conversational AI
Authors: name: Shuhaib Mehri, name: Xiaocheng Yang, name: Takyoung Kim, name: Gokhan Tur, name: Shikib Mehri, name: Dilek Hakkani-Tür

User simulators are essential to conversational AI, enabling scalable agent
development and evaluation through simulated interactions. While current Large
Language Models (LLMs) have advanced user simulation capabilities, we reveal
that they struggle to consistently demonstrate goal-oriented behavior across
multi-turn conversations--a critical limitation that compromises their
reliability in downstream applications. We introduce User Goal State Tracking
(UGST), a novel framework that tracks user goal progression throughout
conversations. Leveraging UGST, we present a three-stage methodology for
developing user simulators that can autonomously track goal progression and
reason to generate goal-aligned responses. Moreover, we establish comprehensive
evaluation metrics for measuring goal alignment in user simulators, and
demonstrate that our approach yields substantial improvements across two
benchmarks (MultiWOZ 2.4 and {\tau}-Bench). Our contributions address a
critical gap in conversational AI and establish UGST as an essential framework
for developing goal-aligned user simulators.