Embodied conversational agents (ECAs) are autonomous software entities with human-like appearance and communication skills. These agents can take on a number of different roles, for example, as an assistant, tutor, information provider, or customer service agent. They may also simply represent or entertain a user.

The precise nature and benefits of different characteristics of ECAs requires careful investigation. Questions range from the function of an eyebrow raise to mechanisms for assessing and improving ECA trustworthiness.

This book will help experts and designers in the specification and development of applications incorporating ECAs. Part 1 provides guidelines for evaluation methodologies and the identification of design and evaluation parameters. Part 2 demonstrates the importance of considering the user's perspective and interaction experience. Part 3 addresses issues in fine-tuning design parameters of ECAs and verifying the perceived effect. Finally, in Part 4 lessons learned from a number of application case studies are presented.

The book is intended for both ECA researchers in academia and industry, and developers and designers interested in applying the technology.

Embodied conversational agents (ECAs) are autonomous software entities with human-like appearance and communication skills. These agents can take on a number of different roles, for example, as an assistant, tutor, information provider, or customer service agent. They may also simply represent or entertain a user.

The precise nature and benefits of different characteristics of ECAs requires careful investigation. Questions range from the function of an eyebrow raise to mechanisms for assessing and improving ECA trustworthiness.

This book will help experts and designers in the specification and development of applications incorporating ECAs. Part 1 provides guidelines for evaluation methodologies and the identification of design and evaluation parameters. Part 2 demonstrates the importance of considering the user's perspective and interaction experience. Part 3 addresses issues in fine-tuning design parameters of ECAs and verifying the perceived effect. Finally, in Part 4 lessons learned from a number of application case studies are presented.

The book is intended for both ECA researchers in academia and industry, and developers and designers interested in applying the technology.

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.