HELSINKI UNIVERSITY OF TECHNOLOGY
Department of Computer Science and Engineering
Author
ABSTRACT OF MASTER’S THESIS
Date
Seppo Nyrkkö
2005-11-17
Pages
87
Title of thesis
Utilisation of RDF models in ontology-based dialogue management
Professorship
Professorship Code
Computer and Information Science
T-61
Supervisor
Docent Timo Honkela
Instructor
Professor Kristiina Jokinen
The thesis deals with cooperative dialogue management methods, and it provides a model for
integrating dialogue management with ontological information. The work is based on the previous
research in dialogue systems, conversation modelling and ontologies, and is part of the building of
a dialogue system which deals with a problem-solving task using domain ontology.
The theoretical part of the thesis describes the requirements for Ideal Cooperation within
Jokinen’s theory of Constructive Dialogue Management (CDM). The approach is illustrated by a
practical example introducing an agent-based dialogue system architecture which was used in the
Interact project. Dialogue planning, which uses atomic dialogue objects as described in Denecke’s
dialogue system framework, is also discussed. The RDF structure and the OWL web ontology
language are also presented with examples of programming tools used in authoring and utilising
the data of the Semantic Web.
The practical work has been done within the TEKES-funded collaboration project 4M, which
includes participants from the University of Helsinki, Helsinki University of Technology and VTT
Information Technology Department. The project focuses on a multilingual speech-based dialogue
system which provides help for a maintenance person by means of ontology-based information
retrieval and logic programming based diagnostics. The thesis gives an overview of the practical
work, and the required properties of a service-oriented mobile and multilingual dialogue system.
A language independent dialogue management component for this purpose is introduced in the
implementation section of the thesis. The component takes the previously introduced aspects of
the theoretical analysis into account, and implements cooperation requirements within the limited
context of the project work. The internal data structures, connecting the dialogue management to
language-specific and diagnostic components are fully based on RDF models, and the semantic
content of the data follows the ontology description developed simultaneously in the 4M-project
for the application domain. The dialogue rules for the dialogue planning, based on Denecke’s
framework, are also programmed in a RDF-based planning language, and the necessary semantics
and data structures are briefly described.
The implementation has been successfully applied in the 4M project’s dialogue system. Sample
runs are demonstrated in the evaluation section of the thesis. Due to restrictions of the 4M
system’s other components, sample runs take place in a simulated problem environment.
However, the results and system properties are compared with the original specifications and
requirements of the system. Although the complete 4M system lacks some of the desired
properties of Ideal Cooperation and complex reasoning, the ontology-based, language independent
dialogue management model presented in the thesis is considered usable, and it will be enhanced
in the forthcoming research.
Keywords
Ontologies, dialogue management models, constructive dialogue management, RDF, OWL