Thebookpresentsa cross-sectionofstate-of-the-artresearchonmultimodalc- pora, a highly interdisciplinary area that is a prerequisite for various specialized disciplines. A number of the papers included are revised and expanded versions ofpapersacceptedtotheInternationalWorkshoponMultimodal Corpora: From Models of Natural Interaction to Systems and Applications, held in conjunction th with the 6 International Conference for Language Resources and Evaluation (LREC) on May 27, 2008, in Marrakech, Morocco. This international workshop series started in 2000 and has since then grown into a regular satellite event of the bi-annual LREC conference, attracting researchers from ?elds as diverse as psychology, arti?cial intelligence, robotics, signal processing, computational linguisticsandhuman-computerinteraction. Tocomplement theselected papers from the 2008 workshop, we invited well-known researchers from corpus coll- tioninitiativestocontributetothisvolume. Wewereabletoobtainseveninvited research articles, including contributions from major international multimodal corpus projects like AMI and SmartWeb, which complement the six selected workshop contributions. All papers underwent a special review process for this volume, resulting in signi?cant revisions and extensions based on the experts' advice. While we were pleased that the 2006 edition of the workshop resulted in a special issue of the Journal of Language Resources and Evaluation, published in 2007, we felt that this was the time for another major publication, given not onlytherapidprogressandincreasedinterestin this researchareabut especially in order to acknowledge the di?culty of disseminating results across discipline borders. The Springer LNAI series is the perfect platform for doing so. We also created the website www. multimodal-corpora.

This book constitutes the proceedings of the 15th International Conference on Intelligent Virtual Agents, IVA 2015, held in Delft, The Netherlands, in August 2015. The 11 full papers, 22 short papers, and 21 demo and poster papers accepted were carefully reviewed and selected from 70 submissions. Constructing and studying intelligent virtual agents requires knowledge , theories, methods, and tools from a wide range of fields such as computer science, psychology, cognitive sciences, communication, linguistics, interactive media, human-computer interaction, and artificial intelligence. The papers are organized in topical sections such as adaptive dialogue and user modeling; cognitive, affective and social models; nonverbal behavior and gestures; pedagogical agents in health and training; tools and frameworks; turn-taking; virtual agent perception studies.