Papers

Episodic memory (EM) is an umbrella term for memory systems that operate with representations of personal history of an entity. The content of EM is related to particular places and moments, and connected to subjective feelings and current goals. Recently, it has been argued that EM is one of the key components contributing to believability of intelligent virtual agents (IVAs), at least when agents interact with humans for more than a couple of minutes, because it... Read more

In this paper, we present our current study on the design of a virtual agent able to express sentences in Sign Language (SL), so-called 'Virtual Signer', in the context of interactive web-based applications. Up now, little work has been carried out on web-based virtual signers. As for current research on virtual signers in standalone applications, it relies on two main approaches: Pre-synthesized animations based on motion capture or rotoscoping, and generated animations, with very little interactivity.... Read more

Currently, applications that focus on providing conversations with virtual humans require extensive work to create robust conversational models. We present a new approach called Human-centered Distributed Conversational Modeling. Using this approach, users create conversational models in a distributed manner. To do this, end-users interact with virtual humans to provide new stimuli (questions and statements), and domain-specific experts (e.g. medical/psychology educators) provide new virtual human responses. Using this process, users become the primary developers of conversational... Read more

We look at how some basic choices in the management of turns influence the impression that people get from an agent. We look at scales concerning personality, emotion and interpersonal stance. We do this by a person perception study, or rather an agent perception study, using simulated conversations that systematically vary basic turn-taking strategies. We show how we can create different impressions of friendliness, rudeness, arousal and several other dimensions by varying the timing of... Read more

We describe the design and evaluation of an agent that uses the fillers um and uh in its speech. We describe an empirical study of human-human dialogue, analyzing gaze behavior during the production of fillers and use this data to develop a model of agent-based gaze behavior. We find that speakers are significantly more likely to gaze away from their dialogue partner while uttering fillers, especially if the filler occurs at the beginning of a... Read more

Several challenges remain in the effort to build software capable of conducting realtime dialogue with people. Part of the problem has been a lack of realtime flexibility, especially with regards to turntaking. We have built a system that can adapt its turntaking behavior in natural dialogue, learning to minimize unwanted interruptions and "awkward silences". The system learns this dynamically during the interaction in less than 30 turns, without special training sessions. Here we describe the... Read more

This paper presents the process of creation of virtual agents used in a virtual reality performance. The performance aimed to investigate how drama and performance could inform the creation of virtual agents and also how virtual reality could raise questions for drama and performance. The virtual agents were based on the performance of 2 actors. This paper describes the process of preparing the actors, capturing their performances and transferring them to the virtual agents. A... Read more

Over the past decade, motion capture data has become a popular research tool, and motion databases have grown exponentially. Indexing, querying, and retrieving data has thus become more difficult, and has necessitated innovative approaches to using these databases. Our aim is to make this approach feasible for virtual agents signing in French Sign Language (LSF), taking into account the semantic information implicitly contained in language data. We thus structure a database in two autonomous units,... Read more

Two tools for developing embodied conversational agents and deploying them over the world-wide web to standard web browsers are presented. DTask is a hierarchical task decomposition-based dialogue planner, based on the CEA-2018 task description language standard. LiteBody is an extensible, web-based BML renderer that runs in most contemporary web browsers with no additional software and provides a conversational virtual agent with a range of conversational nonverbal behavior adequate for many user-agent interaction applications. Together, these... Read more

Agents cannot be decoupled from their environment. An agent perceives and acts in a world and the model of the world influences how the agent makes decisions. Most systems with virtual embodied agents simulate the environment within a specific realization engine such as the graphics engine. As a consequence, these agents are bound to a particular kind of environment which compromises their reusability across different applications. We propose the ION Framework, a framework for simulating... Read more