Marie-Laure Ryan is an independent scholar. She is the author of Possible Worlds, Artificial Intelligence, and Narrative Theory; Narrative as Virtual Reality; and Avatars of Story, as well as the editor of Narrative across Media (Nebraska, 2004), among others. Jan-No"Thon is a research associate in the Department of Media Studies at the University of T"bingen. Most recently, he has coedited From Comic Strips to Graphic Novels: Contributions to the Theory and History of Graphic Narrative.