Lechen Zhang

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Hi, I am Lechen! I am an incoming Ph.D. Student in Computer Science at University of Illinois Urbana-Champaign, with a broad interest in Natural Language Processing and Machine Learning. My research focuses on developing robust and trustworthy language models that better understand, generalize and think like humans.

Currently I am a Research Assistant in Blablablab, advised by Professor David Jurgens. I am also working with Professor Lu Wang as a member of Launch Lab. Previously, I earned my master’s degree from University of Michigan and my bachelor’s degree from Shanghai Jiao Tong University.

You can find my CV here.

news

Apr 15, 2025 I’m excited to share that I’ll be joining UIUC this fall. Looking forward to meeting new friends!
Nov 12, 2024 Excited to Attend EMNLP 2024! See you in Miami :palm_tree:
Oct 15, 2024 Submitting 4 new papers in this cycle! Check out our newly released preprints about System Prompting, Factuality Evaluation, and Human-AI Dialog Simulation.
Jun 18, 2024 I am presenting our paper at NAACL 2024 today. Check our slides here!
May 20, 2024 I am thrilled to join Launch Lab working with Professor Lu Wang!

selected publications

* indicates equal contribution
  1. NAACL 2024
    Oral
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    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
  2. NAACL 2025
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    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
  3. ACL 2025
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    FactBench: A Dynamic Benchmark for In-the-Wild Language Model Factuality Evaluation
    Farima Fatahi Bayat, Lechen Zhang, Sheza Munir, and Lu Wang
    arXiv preprint arXiv:2410.22257, Oct 2024
    arXiv Code Twitter
  4. ACL 2025 Findings
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    Towards 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 Diab
    arXiv preprint arXiv:2412.18367, Dec 2024
    arXiv
  5. Preprint
    Under Review
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    SPRIG: Improving Large Language Model Performance by System Prompt Optimization
    Lechen Zhang, Tolga Ergen, Lajanugen Logeswaran, Moontae Lee, and David Jurgens
    arXiv preprint arXiv:2410.14826, Oct 2024
    arXiv Code Slides Twitter
  6. Under Review
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    Latent Geographies: Joint Embeddings of Text and Visual Cues for Social Media Geolocation
    Lechen Zhang*, Abraham Israeli*, Rohan Raju, and David Jurgens
    May 2025
  7. Preprint
    Under Review
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    VeriFact: Enhancing Long-Form Factuality Evaluation with Refined Fact Extraction and Reference Facts
    Xin Liu, Lechen Zhang, Sheza Munir, Yiyang Gu, and Lu Wang
    arXiv preprint arXiv:2505.09701, May 2025
    arXiv
  8. Preprint
    Under Review
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    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