Zamaraeva, OlgaFlickinger, DanBond, FrancisGómez-Rodríguez, Carlos2026-02-232026-02-232025O. Zamaraeva, D. Flickinger, F. Bond, y C. Gómez-Rodríguez, «Comparing LLM-generated and human-authored news text using formal syntactic theory», en Proceedings of the 63rd Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers), Vienna, Austria: Association for Computational Linguistics, 2025, pp. 9041-9060. doi: 10.18653/v1/2025.acl-long.443.979-8-89176-251-00736-587Xhttps://hdl.handle.net/2183/47473The Congress took place in Vienna, Austria from July 27 to August 1st, 2025[Abstract]: This study provides the first comprehensive comparison of New York Times-style text generated by six large language models against real, human-authored NYT writing. The comparison is based on a formal syntactic theory. We use Head-driven Phrase Structure Grammar (HPSG) to analyze the grammatical structure of the texts. We then investigate and illustrate the differences in the distributions of HPSG grammar types, revealing systematic distinctions between human and LLM-generated writing. These findings contribute to a deeper understanding of the syntactic behavior of LLMs as well as humans, within the NYT genre.eng©2025 Association for Computational LinguisticsAttribution 4.0 Internationalhttp://creativecommons.org/licenses/by/4.0/Large Language Models (LLMs)Head-driven Phrase Structure Grammar (HPSG)English Resource Grammar (ERG)Formal Syntactic TheoryLinguistic Diversity Analysisconference outputopen access10.18653/v1/2025.acl-long.443