From Monologue to Dialogue: Natural Language Generation in OVIS

This paper describes how a language generation system that was originally designed for monologue generation, has been adapted for use in the OVIS spoken dialogue system. To meet the requirement that in a dialogue, the system's utterances should make up a single, coherent dialogue turn, several modifications had to be made to the system. The paper also discusses the influence of dialogue context on information status, and its consequences for the generation of referring expressions and accentuation

Using Out-of-Character Reasoning to Combine Storytelling and Education in a Serious Game

To reconcile storytelling and educational meta-goals in the context of a serious game, we propose to make use of out-of-character reasoning in virtual agents. We will implement these agents in a serious game of our design, which will focus on social interaction in conflict scenarios with the meta-goal of improving social awareness of users. The agents will use out-of-character reasoning to manage conflicts by assuming different in-character personalities or by planning to take specific actions based on interaction with the users. In-character reasoning is responsible for the storytelling concerns of character believability and consistency. These are not endangered by out-of-character reasoning, as it takes in-character information into account when making decisions

Cueing the Virtual Storyteller: Analysis of cue phrase usage in fairy tales

An existing taxonomy of Dutch cue phrases, designed for use in story generation, was validated by analysing cue phrase usage in a corpus of classical fairy tales. The analysis led to some adaptations of the original taxonomy

The Virtual Storyteller: story generation by simulation

The Virtual Storyteller is a multi-agent framework that generates stories based on a concept called emergent narrative. In this paper, we describe the motivation and approach of the Virtual Storyteller, and give an overview of the computational processes involved in the story generation process. We also discuss some of the challenges posed by our chosen approach

ANGELICA : choice of output modality in an embodied agent

The ANGELICA project addresses the problem of modality choice in information presentation by embodied, humanlike agents. The output modalities available to such agents include both language and various nonverbal signals such as pointing and gesturing. For each piece of information to be presented by the agent it must be decided whether it should be expressed using language, a nonverbal signal, or both. In the ANGELICA project a model of the different factors influencing this choice will be developed and integrated in a natural language generation system. The application domain is the presentation of route descriptions by an embodied agent in a 3D environment. Evaluation and testing form an integral part of the project. In particular, we will investigate the effect of different modality choices on the effectiveness and naturalness of the generated presentations and on the user's perception of the agent's personality

How Do I Address You? Modelling addressing behavior based on an analysis of a multi-modal corpora of conversational discourse

Addressing is a special kind of referring and thus principles of multi-modal referring expression generation will also be basic for generation of address terms and addressing gestures for conversational agents. Addressing is a special kind of referring because of the different (second person instead of object) role that the referent has in the interaction. Based on an analysis of addressing behaviour in multi-party face-to-face conversations (meetings, TV discussions as well as theater plays), we present outlines of a model for generating multi-modal verbal and non-verbal addressing behaviour for agents in multi-party interactions

The Narrator: NLG for digital storytelling

We present the Narrator, an NLG component used for the generation of narratives in a digital storytelling system. We describe how the Narrator works and show some examples of generated stories

Politeness and Alignment in Dialogues with a Virtual Guide

Language alignment is something that happens automatically in dialogues between human speakers. The ability to align is expected to increase the believability of virtual dialogue agents. In this paper we extend the notion of alignment to affective language use, describing a model for dynamically adapting the linguistic style of a virtual agent to the level of politeness and formality detected in the user’s utterances. The model has been implemented in the Virtual Guide, an embodied conversational agent giving directions in a virtual environment. Evaluation shows that our formality model needs improvement, but that the politeness tactics used by the Guide are mostly interpreted as intended, and that the alignment to the user’s language is noticeable

Generating Instructions in a 3D Game Environment: Efficiency or Entertainment?

The GIVE Challenge was designed for the evaluation of natural language generation (NLG) systems. It involved the automatic generation of instructions for users in a 3D environment. In this paper we introduce two NLG systems that we developed for this challenge. One system focused on generating optimally helpful instructions while the other focused on entertainment. We used the data gathered in the Challenge to compare the efficiency and entertainment value of both systems. We found a clear difference in efficiency, but were unable to prove that one system was more entertaining than the other. This could be explained by the fact that the set-up and evaluation methods of the GIVE Challenge were not aimed at entertainment