publications

2026

1. ICLR 2026

   

   SPRIG: Improving Large Language Model Performance by System Prompt Optimization

   Lechen Zhang, Tolga Ergen, Lajanugen Logeswaran, Moontae Lee, and David Jurgens

   In The Fourteenth International Conference on Learning Representations, Apr 2026

   arXiv Code Slides Twitter

2025

1. Preprint

   Under Review

   

   Cross-Lingual Prompt Steerability: Towards Accurate and Robust LLM Behavior across Languages

   Lechen Zhang^*, Yusheng Zhou^*, Tolga Ergen, Lajanugen Logeswaran, Moontae Lee, and David Jurgens

   arXiv preprint arXiv:2512.02841, Dec 2025

   arXiv Code
2. MATH-AI @ NIPS 2025

   Under Review

   

   Skill-Aware Data Selection and Fine-Tuning for Data-Efficient Reasoning Distillation

   Lechen Zhang, Yunxiang Zhang, Wei Hu, and Lu Wang

   In The 5th Workshop on Mathematical Reasoning and AI at NeurIPS 2025, Dec 2025

   arXiv Code
3. EMNLP 2025

   

   VeriFact: Enhancing Long-Form Factuality Evaluation with Refined Fact Extraction and Reference Facts

   Xin Liu, Lechen Zhang, Sheza Munir, Yiyang Gu, and Lu Wang

   In Proceedings of the 2025 Conference on Empirical Methods in Natural Language Processing, Nov 2025

   DOI arXiv Code
4. SCALR @ COLM 2025

   Under Review

   

   Logit Arithmetic Elicits Long Reasoning Capabilities Without Training

   Yunxiang Zhang, Muhammad Khalifa, Lechen Zhang, Xin Liu, Ayoung Lee, Xinliang Frederick Zhang, Farima Fatahi Bayat, and Lu Wang

   In The 1st Workshop on Test-time Scaling and Reasoning Models at COLM 2025, Oct 2025

   arXiv Code
5. ACL 2025

   Oral

   

   FactBench: A Dynamic Benchmark for In-the-Wild Language Model Factuality Evaluation

   Farima Fatahi Bayat, Lechen Zhang, Sheza Munir, and Lu Wang

   In Proceedings of the 63rd Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers), Jul 2025

   DOI arXiv Code Twitter
6. ACL 2025 Findings

   

   Toward Global AI Inclusivity: A Large-Scale Multilingual Terminology Dataset (GIST)

   Jiarui Liu, Iman Ouzzani, Wenkai Li, Lechen Zhang, Tianyue Ou, Houda Bouamor, Zhijing Jin, and Mona T. Diab

   In Findings of the Association for Computational Linguistics: ACL 2025, Jul 2025

   DOI arXiv
7. NAACL 2025

   

   Causally Modeling the Linguistic and Social Factors that Predict Email Response

   Yinuo Xu^*, Hong Chen^*, Sushrita Rakshit^*, Aparna Ananthasubramaniam^*, Omkar Yadav^*, Mingqian Zheng^*, Michael Jiang^*, Lechen Zhang^*, Bowen Yi^*, Kenan Alkiek^*, Abraham Israeli^*, Bangzhao Shu^*, Hua Shen^*, Jiaxin Pei^*, Haotian Zhang^*, Miriam Schirmer^*, and David Jurgens

   In Proceedings of the 2025 Conference of the Nations of the Americas Chapter of the Association for Computational Linguistics: Human Language Technologies (Volume 1: Long Papers), Apr 2025

   DOI Code

2024

1. Under Review

   

   Latent Geographies: Joint Embeddings of Text and Visual Cues for Social Media Geolocation

   Lechen Zhang^*, Abraham Israeli^*, Rohan Raju, and David Jurgens

   Oct 2024
2. Preprint

   Under Review

   

   Real or Robotic? Assessing Whether LLMs Accurately Simulate Qualities of Human Responses in Dialogue

   Jonathan Ivey^*, Shivani Kumar^*, Jiayu Liu^*, Hua Shen^*, Sushrita Rakshit^*, Rohan Raju^*, Haotian Zhang^*, Aparna Ananthasubramaniam^*, Junghwan Kim^*, Bowen Yi^*, Dustin Wright^*, Abraham Israeli^*, Anders Giovanni Møller^*, Lechen Zhang^*, and David Jurgens

   arXiv preprint arXiv:2409.08330, Sep 2024

   arXiv Code Twitter
3. NAACL 2024

   Oral

   

   You don’t need a personality test to know these models are unreliable: Assessing the Reliability of Large Language Models on Psychometric Instruments

   Bangzhao Shu^*, Lechen Zhang^*, Minje Choi, Lavinia Dunagan, Lajanugen Logeswaran, Moontae Lee, Dallas Card, and David Jurgens

   In Proceedings of the 2024 Conference of the North American Chapter of the Association for Computational Linguistics (NAACL), Jun 2024

   DOI arXiv Code Slides Twitter