Welcome to the proceedings of the 9th International Conference on Intelligent Virtual Agents, held September 14-16, 2009 in Amsterdam, The Netherlands. Intelligent virtual agents (IVAs) are interactive characters that exhibit hum- like qualities and communicate with humans or with each other using natural human modalities such as speech and gesture. They are capable of real-time perception, cognition and action, allowing them to participate in a dynamic physical and social environment. IVA is an interdisciplinary annual conference and the main forum for p- senting research on modeling, developing and evaluating IVAs with a focus on communicative abilities and social behavior. The development of IVAs requires expertise in multimodal interaction and several AI ?elds such as cognitive m- eling, planning, vision and natural language processing. Computational models are typically based on experimental studies and theories of human-human and human-robot interaction; conversely, IVA technology may provide interesting lessons for these ?elds. The realization of engaging IVAs is a challenging task, so reusable modules and tools are of great value. The ?elds of application range from robot assistants, social simulation and tutoring to games and artistic - ploration.

This book constitutes the refereed proceedings of the 11th International Conference on Intelligent Virtual Agents, IVA 2011, held in Reykjavik, Island, in September 2011. The 18 revised full papers and 27 revised short papers presented together with 25 poster papers were carefully reviewed and selected from 91 submissions. The papers are organized in topical sections on social and dramatic interaction; guides and relational agents; nonverbal behavior; adaptation and coordination; listening and feedback; frameworks and tools; cooperation and copresence; emotion; poster abstracts.