4.1.1 Introduction

Dialogue is at the same time the most fundamental and broadly used form of language, as well as the most complex one.

Dialogue is at the same time the most fundamental and broadly used form of language, as well as the most complex one. And most of all, dialogue is the most natural medium of communication for human beings. It is these aspects of dialogue that make its modelling a research area of its own, and one of greatest interest at that. In many cases of interaction between humans and machines, using dialogue may enables better results with regard to the target each time.

We now consider some general desired characteristics that any dialogue system should have, and give examples in the form of dialogue fragments. This will serve as background when we look at a real life-application of dialogue processing with finite state techniques, namely at the speaking elevator of the Computational Linguistics department of Saarland University.

But before we do any of that, have a look at the following.

ELIZA

Eliza (to be found here) is one of the first dialogue systems. You can regard it as your friend. Tell it your problems and it will try to help you. It cannot really understand what you tell it. It picks on words that it then maps onto specific output. Play with it for fun. Do try to work out how it operates!