Dialogue generation in character-based interactive storytelling

In recent years, there has been significant progress in developing Interactive Storytelling systems, in particular in terms of the underlying AI techniques. There has been an emerging consensus on the AI approach, in particular the use of planning systems. However, these have concentrated on the generation of a sequence of narrative actions, staged through the behaviour of virtual actors. In order to achieve the long-term objective of implementing interactive media that would reproduce the aesthetic qualities of traditional films, most interactive storytelling systems are still missing the ability to generate dialogues between characters. We describe an extension of our Interactive Storytelling approach which integrates dialogue generation within narrative situations. Our unit of generation is the dialogue act (pair of utterances) and one main objective is to reproduce realistic dialogue phenomena based on implicit forms of expression. The emphasis is also on adopting a unified approach relating narrative representations to the linguistic form of the generated utterances. From a representation of active narrative goals and the emotional affinity between characters, our system is able to derive a set of parameters governing various aspects of the linguistic form to be generated. We illustrate this approach on several implemented examples.