*_Notice and Invitation_*
Oral Defense of Doctoral Dissertation
The Volgenau School of Engineering, George Mason University

*Mohammad Ababneh*
Bachelor of Science, Mu'tah University, 1994
Master of Science, Naval Postgraduate School, 2000


A Dynamic Dialog System Using Semantic Web Technologies

Thursday, 01/16/2014, 11:00AM
Room 4801, Engineering Building

All are invited to attend.

Dr. Duminda Wijesekera, Chair
Dr. Arun Sood
Dr. Rao Mulpuri

Dr. Paulo Costa


A dialog system or a conversational agent provides a means for a human 
to interact with a computer system. Dialog systems use text, voice and 
other means to carry out conversations with humans in order to achieve 
some objective. Most dialog systems are created with specific objectives 
in mind and consist of pre-programmed conversations. The primary 
objective of this dissertation is to show that dialogs can be 
dynamically generated using semantic technologies. I show the 
feasibility by constructing a dialog system that can be specific to 
control physical entry points, and that can withstand an attempt to 
misuse the system by playing back previously recorded conversations. As 
a solution my system randomly generates questions with a pre-specified 
difficulty level and relevance, thereby not repeating conversations. In 
order to do so, my system uses policies to govern the entrance rules, 
and Item Response Theory to select questions derived from ontologies 
relevant to those policies. Furthermore, by using contextual reasoning 
to derive facts from a chosen context, my dialog system can be directed 
to generate questions that are randomized within a topic, yet relevant 
to the task at hand. My system design has been prototyped using a voice 
interface. The prototype demonstrates acceptable performance on 
benchmark data.

A copy of this doctoral dissertation is on reserve at the Johnson Center