VIRENA: Virtual Arena for Research, Education, and Democratic Innovation

Digital platforms shape how people communicate, deliberate, and form opinions. Studying these dynamics has become harder because of restricted data access, ethical limits on real-world experiments, and the technical demands of existing research tools. VIRENA (Virtual Arena) is a platform for controlled experiments in realistic social media environments. Several participants can interact at the same time in replicas of feed-based platforms (Instagram, Facebook, Reddit, X) and messaging apps (WhatsApp, Messenger). AI agents powered by large language models (LLMs) join the participants with configurable personas and human-like timing. Researchers set up experiments in a visual interface without programming: they define conditions, schedule stimulus content, add moderation rules, assign participants randomly to conditions, and export the data. VIRENA supports designs that were hard to run before, such as studying human--AI interaction in realistic social settings, comparing moderation interventions, and observing group deliberation as it unfolds. Participants and data stay within institutional control, and the platform links to survey and recruitment tools. This paper describes how VIRENA works and how to use it.