Explaining Generalization of AI-Generated Text Detectors Through Linguistic Analysis

Yuxi Xia, Kinga Stańczak, Benjamin Roth


Abstract
AI-text detectors achieve high accuracy on in-domain benchmarks, but often struggle to generalize across different generation conditions such as unseen prompts, model families, or domains. While prior work has reported these generalization gaps, there are limited insights about the underlying causes. In this work, we present a systematic study aimed at explaining generalization behavior through linguistic analysis. We construct a comprehensive benchmark that spans 6 prompting strategies, 7 large language models (LLMs), and 4 domain datasets, resulting in a diverse set of human- and AI-generated texts. Using this dataset, we fine-tune classification-based detectors on various generation settings and evaluate their cross-prompt, cross-model, and cross-dataset generalization. To explain the performance variance, we compute correlations between generalization accuracies and feature shifts of 80 linguistic features between training and test conditions. Our analysis reveals that generalization performance for specific detectors and evaluation conditions is significantly associated with linguistic features such as tense usage and pronoun frequency.
Anthology ID:
2026.eacl-long.307
Volume:
Proceedings of the 19th Conference of the European Chapter of the Association for Computational Linguistics (Volume 1: Long Papers)
Month:
March
Year:
2026
Address:
Rabat, Morocco
Editors:
Vera Demberg, Kentaro Inui, Lluís Marquez
Venue:
EACL
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
6524–6546
Language:
URL:
https://preview.aclanthology.org/ingest-eacl/2026.eacl-long.307/
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Bibkey:
Cite (ACL):
Yuxi Xia, Kinga Stańczak, and Benjamin Roth. 2026. Explaining Generalization of AI-Generated Text Detectors Through Linguistic Analysis. In Proceedings of the 19th Conference of the European Chapter of the Association for Computational Linguistics (Volume 1: Long Papers), pages 6524–6546, Rabat, Morocco. Association for Computational Linguistics.
Cite (Informal):
Explaining Generalization of AI-Generated Text Detectors Through Linguistic Analysis (Xia et al., EACL 2026)
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https://preview.aclanthology.org/ingest-eacl/2026.eacl-long.307.pdf