Dialogue management systems: a survey and overview

This report provides an overview of the current issues and techniques for the modelling of dialogues using a computer. A dialogue management system can manage a dialogue between two or more agents, be they human or computer. Recently, increasingly complex dialogues are being modelled which allow a range of discourse phenomena including ellipsis and anaphoric reference. Such dialogues are thought to be similar to those between two humans, and accurate modelling of these phenomena leads to "pleasant", i.e. easy to talk to, and natural human-computer dialogues. Dialogue management can be classified into three often overlapping approaches: discourse grammars, plan-based and collaborative approaches. The design of a system often begins by eliciting the language used initially between two humans and later by Wizard of Oz experiments. Special issues relating to dialogue management systems are discussed including recovery strategies from different types of errors and the coding of dialogue in corpora. Lastly, approaches to evaluation are briefly discussed from the qualitative and quantitative viewpoints, recognising the importance and size of this sub-field.