An Empirical Study on Zero-Data Bootstrapping for Conversational Recommender Systems

Rohan Surana, Junda Wu, Zhouhang Xie, Yu Xia, Nathan Kallus, Julian McAuley


Abstract
Conversational Recommender Systems (CRS) typically require domain-specific dialogue data, which is costly, scarce, and often unavailable in new domains. We conduct a systematic empirical study of zero-data CRS bootstrapping: generating synthetic conversational supervision from non-conversational signals—item reviews, metadata, and user-item interactions—without any in-domain dialogue corpus. We compare two information-theoretic selection strategies, Jensen-Shannon diversity and Fisher information, across domain signals, model architectures, datasets, and fine-tuning paradigms. Our results show that domain-grounded synthetic data consistently outperforms zero-shot prompting and naive synthetic baselines; active selection improves data efficiency over random sampling; metadata and collaborative filtering signals each improve selection quality; and, in low-resource settings, synthetic data can outperform scarce real dialogues while further complementing them. These findings establish non-conversational domain signals as a viable path toward building CRS without conversational training data. The code is available at https://anonymous.4open.science/r/zero_data_crs/ .
Anthology ID:
2026.findings-emnlp.736
Volume:
Findings of the Association for Computational Linguistics: EMNLP 2026
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
Findings
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
15455–15472
Language:
URL:
https://aclanthology.org/2026.findings-emnlp.736/
DOI:
Bibkey:
Cite (ACL):
Rohan Surana, Junda Wu, Zhouhang Xie, Yu Xia, Nathan Kallus, and Julian McAuley. 2026. An Empirical Study on Zero-Data Bootstrapping for Conversational Recommender Systems. In Findings of the Association for Computational Linguistics: EMNLP 2026, pages 15455–15472, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
An Empirical Study on Zero-Data Bootstrapping for Conversational Recommender Systems (Surana et al., Findings 2026)
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PDF:
https://aclanthology.org/2026.findings-emnlp.736.pdf