University of Bari

Department of Informatics

Intelligent Interfaces


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Wizard of Oz studies with ECAs




Overview

Embodied Conversational Agents (ECAs) are seen as a new metaphor of human-computer interaction which should give the users the illusion of cooperating with a human partner rather than just ‘using a tool’. The more these agents succeed in achieving this goal, the more their users are expected to show some sign of ‘social relationship’ with them: ECAs should be equipped to notice these signs and to respond appropriately.

 

Objective

To design realistic dialogs between humans and ECAs and, in particular, how signs of 'social relationship' of the user may be recognized, we are performing a set of Wizard of Oz studies with an ad hoc tool. Volunteer subjects were told that they were helping us to evaluate a working system. In reality, a 'Wizard' was playing the role of the dialog simulation system, so that we could register and study how the subjects interacted with it.

We use the corpus collected with these studies as a body of knowledge on which to ground research on emotion recognition through natural language analysis. As the tool is very flexible, it enables performing studies in a variety of situations: in different languages, different application domains, with different text-to-speech synthethizers and different ECAs.

Participants

Tool design and implementation:

Giuseppe Clarizio
Berardina De Carolis

Studies:

Dora Cavalluzzi
Fiorella de Rosis
Irene Mazzotta
Nicole Novielli

Architecture and Language

 

This tool is based on a client-server architecture, is written in Visual Basic 6.0 and uses several libraries and components (see figure).

The characters we employed so far belong to the Haptek gallery.
The English Text-To-Speech synthesizer is from Microsoft, while the Italian version was kindly provided by Loquendo, in the scope of a research agreement with our Department.

Changing the ECA is easy, provided another apml-character wrapper is implemented. If you want to use a new wrapper, you just have to create the corresponding executable file.
The TTS is a component integrated in our Haptek wrapper and is separated from the other applications: you may therefore use any TTS for your ECA wrapper.



The application uses a Client-Server connection through 220482 and 230585 ports. The Oz tool runs in the server side and the subject in the client side.

In the server side, you can select the experiment conditions (domain, social relation, agent's personality, evaluation method) and the input mode -speech or text-: with these settings, you will indirectly select the path in which the apml files which represent the agent's moves to employ in your study are stored.

Publications

How it works


When both the applications have been started and the connection has been established, the experiment may begin.

The user playing the role of the Wizard selects one of the available agent moves in the hierarchical menu by clicking on it: the corresponding apml file is then sent to the subject side and the haptek wrapper executes it.

Subjects may respond, in their turn, with the initially selected modality (text or speech input) and the dialog between the ECA and the subject goes on, by alternating the two participant's moves.

When the subject wants to stop the dialog, he or she may click on the “Stop the dialog” button: a final questionnaire to be filled will then be displayed.

The questionnaire results are sent to Oz when the subject clicks on the “Confirm Evaluation” button.

For more information on how to use this tool, give a look at G. Clarizio: How to use the WoZ tool.


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