Valid Survey Simulations with Limited Human Data: The Roles of Prompting, Fine-Tuning, and Rectification
Stefan Krsteski, Giuseppe Russo, Serina Chang, Robert West, Kristina Gligori\'c
Abstract
Surveys provide valuable insights into public opinion and behavior, but their execution is costly and slow. Large language models (LLMs) have been proposed as a scalable, low-cost substitute for human respondents, but their outputs are often biased and yield invalid estimates. We study the interplay between synthesis methods that use LLMs to generate survey responses and rectification methods that debias population estimates, and explore how human responses are best allocated between them. Using two panel surveys with questions on nutrition, politics, and economics, we find that synthesis alone introduces substantial bias (24–86%), whereas combining it with rectification reduces bias below 5% and increases effective sample size by up to 14%. Overall, we challenge the common practice of using all human responses for fine-tuning, showing that under a fixed budget, allocating most to rectification results in far more effective estimation.- Anthology ID:
- 2026.acl-long.498
- Volume:
- Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
- Month:
- July
- Year:
- 2026
- Address:
- San Diego, California, United States
- Editors:
- Maria Liakata, Viviane P. Moreira, Jiajun Zhang, David Jurgens
- Venue:
- ACL
- SIG:
- Publisher:
- Association for Computational Linguistics
- Note:
- Pages:
- 10887–10906
- Language:
- URL:
- https://preview.aclanthology.org/ingest-acl/2026.acl-long.498/
- DOI:
- Cite (ACL):
- Stefan Krsteski, Giuseppe Russo, Serina Chang, Robert West, and Kristina Gligori\'c. 2026. Valid Survey Simulations with Limited Human Data: The Roles of Prompting, Fine-Tuning, and Rectification. In Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers), pages 10887–10906, San Diego, California, United States. Association for Computational Linguistics.
- Cite (Informal):
- Valid Survey Simulations with Limited Human Data: The Roles of Prompting, Fine-Tuning, and Rectification (Krsteski et al., ACL 2026)
- PDF:
- https://preview.aclanthology.org/ingest-acl/2026.acl-long.498.pdf