MPML: a markup language for controlling the behavior of life-like characters

Animated agents have the potential to convey information in a more natural way than other media traditionally used on the world-wide web, such as text, audio, or video clips. They also allow for more natural styles of human-computer interaction than navigation through hypertext documents. In this paper, we will introduce the multi-modal presentation markup language (MPML), which is a powerful and easy-to-use XM L-style language enabling content authors to script rich web-based interaction scenarios featuring life-like characters. MPML is a powerful language as it provides controls for the verbal and non-verbal behavior of affective 2D cartoon-style characters, presentation flow, and the integration of external objects, like Java applets. MPML is easy-to-use since we also offer a graphical scripting environment (a visual editor) that facilitates the creation of complex presentation scripts. We will describe the tagging structures of MPML, the MPML3.0 Visual Editor, and illustrate the usefulness of the tagging structures of the language by the actual implementation of a web-based casino where the user may interact with life-like characters. (C) 2004 Elsevier Ltd. All rights reserved.