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During the pandemic, the wave of COVID-19 fake news spread as fast as the virus itself, hitting even languages less present in the digital world, like Romanian. To stem the tide, a research team built a brand-new Romanian dataset, collecting virus-related fake articles and sorting them into "super-narratives": major recurring themes like anti-vax propaganda, conspiracy theories, or blaming foreign powers.

The challenge was teaching an AI to spot them automatically. They tested several Large Language Models (LLMs), including LLaMA 3.1 8B, trying four strategies: from zero-shot learning (no examples) to few-shot (a handful of examples), up to classic supervised learning. The real breakthrough came with semi-supervised learning: the model studies a mountain of unlabeled text to grasp the language, then fine-tunes its aim on a few human-guided cases. The result? An F1-score of 78.81%, beating old classifiers based on grammar and syntax.

This approach is a breath of fresh air for "low-resource languages", often ignored by major systems. It also paves the way for real-time fact-checking and transparent explanations: the AI doesn't just say "it's false", but shows why and with which arguments to counter it. A step forward for healthier information, in any language.

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The study, published in *Information* (Vol. 16, Art. 796), addresses a critical gap: most anti-disinformation benchmarks (e.g., FakeNewsNet, LIAR) are Anglo-centric. Researchers built **RoCoFake**, a dataset of 4,000+ Romanian articles (half annotated at document level with 6 super-narratives: anti-vax, conspiracy, geopolitics, alternative cure, denialism, civil liberties; half unannotated).

The winning architecture uses **LLaMA 3.1 8B** with **LoRA (Low-Rank Adaptation)** for parameter efficiency. The semi-supervised pipeline follows a **Self-Training** scheme: 1) Supervised fine-tuning on the annotated subset (10% data). 2) Inference on the unannotated pool to generate high-confidence pseudo-labels (threshold > 0.9). 3) Retraining on the combined set (gold + pseudo). This cycle iterates 3 times.

Key results: Binary F1 89.2% vs 82.1% (SVM + TF-IDF + UDPipe morphosyntactic features); Multi-class Macro F1 78.8% vs 65.4% (baseline). Error analysis reveals confusion between semantically overlapping classes (e.g., "conspiracy" vs "geopolitics"), suggesting the need for *hierarchical classification* or *contrastive learning* to better separate the latent space. Code and data are released open-source to foster reproducibility in multilingual low-resource settings.

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Authors:
Alexandru DimaEcaterina IlisDiana FloreaMihai Dascalu
Date Published:
Original Article www.mdpi.com
Fact-check verified on 15/08/2026
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Creative Commons License CC BY-NC-SA 4.0

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