Modeling Grooming as a Conversational Phenomenon: The Importance of Turn Progression in Detecting Predatory Conversations

  • João Marcos Tomáz S. Campos UFMG
  • Diogo T. Chaves UFMG
  • Rafael M. Gomes UFMG
  • Wagner Meira Jr. UFMG
  • Marcos André Gonçalves UFMG
  • Leonardo Rocha UFSJ

Abstract


Online grooming detection is commonly formulated as a text classification task, although predatory behavior emerges through a progressive conversational process involving trust building, emotional bonding, and gradual escalation. This paper investigates whether grooming is better characterized as a conversational modeling problem than as a conventional document classification task. Using the PAN12 Sexual Predator Identification benchmark, we systematically compare lexical, distributed, contextual, and long-context representations combined with supervised classifiers, in-context learning, pre-trained moderation models, and hierarchical conversational architectures. To explicitly model conversational progression, we introduce the Contextual Grooming Pattern Network (CGPN), a turn-level architecture that encodes conversational turns with MiniLM and models their temporal evolution through a bidirectional GRU with attention pooling. CGPN achieves the best overall performance, outperforming flat-concatenation approaches and demonstrating that preserving conversational structure provides complementary information beyond aggregated textual content. We further show that discriminative signals emerge within the first 25% of the dialogue and that effective detection depends less on explicit toxicity than on relational patterns such as affection, connection, isolation, information seeking, and gradual escalation. Across linguistic, structural, early-detection, and explainability analyses, the results provide converging evidence that grooming is fundamentally a progressive conversational phenomenon and that explicitly modeling turn dynamics is critical for its detection.
Keywords: Online grooming detection, conversational modeling, text representation, contextual embeddings, explainable AI

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Published
2026-10-27
CAMPOS, João Marcos Tomáz S.; CHAVES, Diogo T.; GOMES, Rafael M.; MEIRA JR., Wagner; GONÇALVES, Marcos André; ROCHA, Leonardo. Modeling Grooming as a Conversational Phenomenon: The Importance of Turn Progression in Detecting Predatory Conversations. In: BRAZILIAN SYMPOSIUM ON MULTIMEDIA AND THE WEB (WEBMEDIA), 32. , 2026, Lavras/MG. Anais [...]. Porto Alegre: Sociedade Brasileira de Computação, 2026 . p. 328-337. DOI: https://doi.org/10.5753/webmedia.2026.30722.

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