A form-based dialogue manager for spoken language applications

A popular approach to dialogue management is based on a finite state model, where user utterances trigger transitions between the dialogue states, and these states, in turn, determine the system´s response. The paper describes an alternative dialogue planning algorithm based on the notion of filling in an electronic form, or “E-form”. Each slot has associated prompts that guide the user through the dialogue, and a priority that determines the order in which the system tries to acquire information. These slots can be optional or mandatory. However, the user is not restricted to follow the system´s lead, and is free to ignore the prompts and take the initiative in the dialogue. The E-form based dialogue planner has been used in an application to search a database of used car advertisements. The goal is to assist the user in selecting, from this database, a small list of cars which match their constraints. For a large number of dialogues collected from over 600 naive users, we found over 70% compliance in answering specific system prompts