Philipe Melo

Jônatas H. dos Santos, Julio C. S. Reis, Philipe Melo et al.

We introduce WhaVax, a new expert-annotated dataset of vaccine-related WhatsApp messages collected from large Brazilian public groups spanning multiple pandemic years. The dataset was constructed through a rigorous, carefully designed pipeline that integrates keyword-based data collection, semantic deduplication to remove near-duplicate content, and a multi-stage annotation protocol conducted by medical specialists. This process produced a high-quality gold-standard corpus, characterized by substantial inter-annotator agreement and strong reliability for downstream analysis. Additionally, we provide a detailed characterization of WhatsApp misinformation, revealing distinctive linguistic, structural, lexical, temporal, and group-level patterns, as well as a meaningful layer of ambiguous cases that reflect the complexity of health discourse in private messaging. We also benchmark classical models, fine-tuned Small Language Models, and zero- or few-shot Large Language Models under realistic data-scarcity constraints, demonstrating that strong embeddings and LLM approaches perform competitively, while domain alignment and data availability remain critical factors. This study provides a rare, high-quality resource to support misinformation research and computational modeling in encrypted communication environments.

Clara Andrade Pimentel, Philipe Melo

Toxic behavior is one of the problems most associated with the gaming community. Reports of hate speech and anti-gaming behavior are common in many online multiplayer games. Many studies address this area, focusing on players and, principally, on the content and its negative impact on the community. However, it is possible that other factors influence the toxicity. In this article, we investigate how game design elements influence toxic behavior, using toxic disinhibition factors as a basis for the analysis. For this, four of the main games of the MOBA genre were analyzed with the support of the MDA Framework and a questionnaire with players. The results show that most players suffered offenses and offended other people in the game, in addition to recognizing MOBA as the genre that generates the most impatience among them. Furthermore, we raise and discuss different elements and mechanics in games that impact the well-being of the community through the individualization of the player, elimination of solidarities, and affirmation of indifference towards toxic behavior. With this, we hope to help game developers and communities to promote integration dynamics.

Julio C. S. Reis, Philipe de Freitas Melo, Kiran Garimella et al.

WhatsApp was alleged to be widely used to spread misinformation and propaganda during elections in Brazil and India. Due to the private encrypted nature of the messages on WhatsApp, it is hard to track the dissemination of misinformation at scale. In this work, using public WhatsApp data, we observe that misinformation has been largely shared on WhatsApp public groups even after they were already fact-checked by popular fact-checking agencies. This represents a significant portion of misinformation spread in both Brazil and India in the groups analyzed. We posit that such misinformation content could be prevented if WhatsApp had a means to flag already fact-checked content. To this end, we propose an architecture that could be implemented by WhatsApp to counter such misinformation. Our proposal respects the current end-to-end encryption architecture on WhatsApp, thus protecting users' privacy while providing an approach to detect the misinformation that benefits from fact-checking efforts.

Clara Andrade Pimentel, Philipe de Freitas Melo, Marília Lyra Bergamo

The use of games within the classroom is in constant growing, however, there are still demands for better solutions to problems such as reconciling leisure with class or the lack of attention of children. This work demonstrates methodologies used to survey and analyze requirements for the development of children's educational games, with the target audience of children from 5 to 9 years old. A list of basic requirements that can improve the development of educational games and provide a basis for further development of a game is raised. It is possible to continue the work by addressing theories of education, the process of gamification of education and other requirements gathering methods.