Lars Qvortrup The world of interactive 3D multimedia is a cross-institutional world. Here, researchers from media studies, linguistics, dramaturgy, media technology, 3D modelling, robotics, computer science, sociology etc. etc. meet. In order not to create a new tower of Babel, it is important to develop a set of common concepts and references. This is the aim of the first section of the book. In Chapter 2, Jens F. Jensen identifies the roots of interaction and interactivity in media studies, literature studies and computer science, and presents definitions of interaction as something going...