Autonomous Fact-Checking: Integrating Local Inference and Adversarial NLP Attacks

  • Rômulo Henrique Nascimento Duarte UFPB
  • Humberto Nunes de Lira UFPB
  • Vivianny Khatly Medeiros Pereira UFPB
  • Isaac Sebastian Lima de Araújo UFPB
  • Allan Gabriel da Cunha Vasconcelos UFPB
  • Yuri de Almeida Malheiros Barbosa UFPB

Resumo


Digital misinformation threatens democratic discourse, especially in low-resource languages like Brazilian Portuguese. We present a fact-checking pipeline comparing structured claim decomposition (Claimify) against full-text extraction across four retrieval-augmented classifiers: gemini-2.5-flash-lite and three local open-weight models (Llama-3.1-8B, Qwen2.5-7B, Gemma-2-9B). Robustness is assessed under characterlevel and synonym perturbations. On a pilot sample, the API-based model shows a preliminary macro-F1 advantage for decomposition, which the three local models fail to replicate consistently. We also observe a systematic bias toward the false label across models.

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Publicado
19/10/2026
DUARTE, Rômulo Henrique Nascimento; LIRA, Humberto Nunes de; PEREIRA, Vivianny Khatly Medeiros; ARAÚJO, Isaac Sebastian Lima de; VASCONCELOS, Allan Gabriel da Cunha; BARBOSA, Yuri de Almeida Malheiros. Autonomous Fact-Checking: Integrating Local Inference and Adversarial NLP Attacks. In: SIMPÓSIO BRASILEIRO DE TECNOLOGIA DA INFORMAÇÃO E DA LINGUAGEM HUMANA (STIL), 17. , 2026, Cuiabá/MT. Anais [...]. Porto Alegre: Sociedade Brasileira de Computação, 2026 . p. 113-125. DOI: https://doi.org/10.5753/stil.2026.26643.