TripScore: Aligning LLMs for Real-World Travel Planning via Expert-Calibrated Reward

Yincen Qu, Huan Xiao, Feng Li, Gregory Li, Hui Zhou, Xiangying Dai, Huang Xuan


Abstract
In our deployed travel-planning service, most users give minimal inputs or free-form requests rather than the structured constraint checklists assumed by existing benchmarks. We therefore present TripScore, a behavior-grounded benchmark and evaluation framework built from real user logs and calibrated against 1,468 pairwise judgments by 203 travel experts. TripScore couples a hierarchical feasibility gate (format and commonsense) with a unified, point-wise reward that aggregates soft quality and preference fulfillment. Using TripScore as both evaluator and reward signal, we benchmark direct prompting, test-time compute, neuro-symbolic solvers, code agents, and fine-tuning. We find that reinforcement learning fine-tuning (e.g., GRPO) provides consistent gains over other approaches under the same base model and practical latency.
Anthology ID:
2026.emnlp-industry.62
Volume:
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing: Industry Track
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Pepa Atanasova, Gholamreza Haffari, Minghan Wang
Venue:
EMNLP
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
1028–1054
Language:
URL:
https://aclanthology.org/2026.emnlp-industry.62/
DOI:
Bibkey:
Cite (ACL):
Yincen Qu, Huan Xiao, Feng Li, Gregory Li, Hui Zhou, Xiangying Dai, and Huang Xuan. 2026. TripScore: Aligning LLMs for Real-World Travel Planning via Expert-Calibrated Reward. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing: Industry Track, pages 1028–1054, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
TripScore: Aligning LLMs for Real-World Travel Planning via Expert-Calibrated Reward (Qu et al., EMNLP 2026)
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PDF:
https://aclanthology.org/2026.emnlp-industry.62.pdf