Embodied conversational agents provide a promising option for presenting information to users. This contribution revisits a number of past and ongoing systems with animated characters that have been developed at DFKI. While in all systems the purpose of using characters is to convey information to the user, there are significant variations in the style of presentation and the assumed conversational setting. The spectrum of systems include systems that feature a single, TV-style presentation agent, dialogue systems, as well as systems that deploy multiple interactive characters. We also provide a technical view on these systems and sketch the underlying system architectures of each sample system.

We present a group recommender system for vacations that helps group members who are not able to communicate synchronously to specify their preferences collaboratively and to arrive at an agreement about an overall solution. The system’s design includes two innovations in visual user interfaces: 1. An interface for collaborative preference specification offers various ways in which one group member can view and perhaps copy the previously specified preferences of other users. This interface has been found to further mutual understanding and agreement. The same interface is used by the system to display recommended solutions and to visualize the extent to which a solution satisfies the preferences of the various group members. 2. In a novel application of animated characters, each character serves as a representative of a group member who is not currently available for communication. By responding with speech, facial expressions, and gesture to proposed solutions,

User support which takes into account the user‘s current context is a key issue of ambient intelligence applications. In this contribution we address the question of how a user may configure and keep control of situated user support. Background of our work is a system, which creates an augmented, personal memory from events perceived in an instrumented environment. We show how the user may –assisted by the system – perform a collaborative introspection of this memory in order to learn about and to exploit past events for user support. In particular we discuss methods for evaluating events and for acquiring proactively feedback in order to improve the quality of a binding between situations and system

Abstract. Virtual agents are traditionally constrained in their embodiment, as they are restricted to one form of body. We propose allowing them to change their embodiment in order to expand their capabilities. This presents users with a number of difficulties in maintaining the identity of the agents, but these can be overcome by using identity cues, certain features that remain constant across embodiment forms. This paper outlines an experiment that examines these identity cues, and shows that they can be used to help address this identity problem. 1

Using 3D Virtual Worlds for commercial activities on the Web and the development of human-like sales assistants operating in such environments are ongoing trends of E-Commerce. The majority of the existing approaches oriented towards the development of such assistants are agent-based and are focused on explicit programming of the agents’ decision making apparatus. While effective in some very specific situations, these approaches often restrict agents’ capabilities to adapt to the changes in the environment and learn new behaviors. In this paper we propose an implicit training method that can address the aforementioned drawbacks. In this method we formalize the virtual environment using Electronic Institutions and make the agent use these formalizations for observing a human principle and learning believable behaviors from the human. The training of the agent can be conducted implicitly using the specific data structures called recursive-arc graphs.

Virtual environments present a suitable platform for the deployment of agent technologies. We advocate a system of virtual agents that are capable of changing their form in order to expand their capability sets. We use strong BDI agents for the control of this adaptation of form and behaviour. This paper outlines a system that allows for adaptable virtual agents, with the ability to change their form to suit the task at hand based upon deliberative reasoning.

pation. From a technical point of view the fourth scenario is certainly most challenging as one has to resolve on an operational level the conflict between predestination and freedom of interaction. Most systems that deploy life-like characters make a concrete commitment to one of the illustrated conversational settings and reflect this decision in a particular system architecture. However, if later on the desire emerges to support other conversational settings as well, an almost complete re-implementation of the application often becomes unavoidable. In contrast, the development of the MIAU platform shows that it is indeed possible to develop a single platform which (a) can be used to construct a broad range of character applications, (b) even allows to switch on-the-fly between director- vs. character-centred scripting approaches, and (c) supports a clear separation between the specification of scripting knowledge (being a knowledge-engineering task), and the required computational

This paper presents an analysis of cross-cultural and linguistic issues in the generation of referring expressions (REs) for English and Japanese dialogues. The analysis is based on a translation activity carried out for a study on the perception of automatically generated REs in a virtual world involving participants in Tokyo and Dublin and complemented by two data elicitation studies. In order to preserve the output of the RE generation algorithm the translation sought to produce a Japanese dialogue in which the REs were as close to the English originals as possible, but within a scenario adapted to the Japanese culture. The two data elicitation experiments assessed Japanese speakers ’ preferences of REs in the same dialogue context. Insights from this work are relevant to the design of RE generation algorithms for use in real-life situations and raise questions as to what extent the current algorithms are transferable between languages and cultures. Results suggest that current approaches to generating REs are biased towards the English language, which becomes apparent when considering, for instance, the realisation of Japanese locative expressions and the absence of a distinction between singular and plural in the Japanese language.