Abstract
This paper reports our sustained and focused research in adopting informal logic dialogue games to develop a computerised system for educational debate. In particular, we consider the usability evaluations of a human-computer debating system we have developed earlier. An expert evaluation and a subsequent user based evaluation have been undertaken. The results from the evaluations are essentially favourable. The evaluations provide evidence for the usability, and the educational and entertainment value of the system. It is anticipated that this work will contribute to the development of human-computer dialogue in general and of computer-based educational dialogue in particular.