In this paper we describe a dialogue system which makes use of the notion of presuppositions to provide a unifying perspective on the function of a dialogue manager. We extend van der Sandt's (1992) treatment of presuppositions in DRT to allow presuppositions to support question-answering, the generation of targeted follow-up questions, the identification of dialogue acts and the semantic disambiguation of questions.

This document describes an extension made to a dialogue-based CALL system, to allow the system to take initiatives in the dialogue. The initiative module is triggered when the user passes the initiative to the system during the course of a dialogue. The system will then generate a set of "possible initiatives" and decide which one is best based on a number of criteria. The initiative

One of the main obstacles to the development of any text generation system is the difficulty of creating the knowledge base from which texts are generated. In particular, a system which performs sentence generation `from scratch' requires a great deal of information about how concepts in its knowledge base are expressed syntactically. Unsurprisingly, it has proven very difficult to build tools which acquire such information from people with no specialist expertise in linguistics and semantics. However, there is another method for acquiring such information which has been largely overlooked: if we want to build a knowledge base that allows full sentence generation, all we need is a bidirectional sentence processing system in which a single declarative grammar supports both sentence generation and sentence interpretation. With such a system, authoring new facts in the knowlege base can be achieved very naturally in the context of a natural language dialogue.

This paper provides an account of the syntactic and semantic representations used in Te Kaitito, a bilingual English/Maori natural language processing system. With the exception of some very simple systems (e.g. Leslie, 1998), the grammar given in Te Kaitito is the first implemented computational grammar for Maori, indeed (we believe) for any Polynesian language. It is therefore of interest to linguists studying these languages. For linguists not specifically working with Maori or Polynesian languages, it might also be interesting as an indication of the extensibility of HPSG to Polynesian languages

In this paper we describe Te Kaitito, a bilingual human-machine dialogue system which supports conversational interactions in English and in Māori, the indigenous language of New Zealand. In particular we consider how Te Kaitito can best be incorporated into Mori second language learning

acquisition system

A lexical authoring tool (Tauira) placed within a bilingual bidirectional dialogue context is described. The tool's dialogue is initiated when one or more unknown words are uttered by the user in the surrounding dialogue system. Based on the context of the sentence the word was uttered in a set of hypotheses are created for possible word types and stems of the unknown word. These hypotheses are reduced using a set of multiple choice questions until only one remains: the new word entry. Hypothesis reduction is done by asking closed questions about the syntactic validity of the unknown word in example sentences. These example sentences are generated based on sentences from the test suite which accompanies the system's grammar. Because the tool operates in a bilingual (English-Maori) context, both the unknown word and its translation are added. The translation for an unknown word is deduced from a translation of the original sentence containing the source word. Not only does this tool provide an interesting addition to the field of lexical authoring but in addition also can side effects of the project can be used to formally evaluate the coverage of a test suite on a grammar concerning word types.