Task Oriented Instructional Dialogue
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TRINDI Annual Report 1998

TRINDI (Task Oriented Instructional Dialogue) is concerned with the use of natural language in human-machine interaction that enables the human to make choices in the performance of a certain task (task oriented instructional dialogues). As one example of this we consider Route Planning as a basic scenario. The application of the research to other scenarios (such as Machine Repair and Software Help) is also being considered. The emphasis of the project is on finding an appropriate way to represent the information which is exchanged in a dialogue. In doing this the project builds on results from a previous LRE project FraCaS (A Framework for Computational Semantics). This is a prerequisite for the development of technologies for machines with more understanding than those presently available in dialogue technology.

Summary of 1998 Activities
The project began work 1st February, 1998. One of the first tasks was to characterize and evaluate the three scenarios and define their role in the project. This gave us a focus to do a brief survey of currently available technology, looking at a number of dialogue management systems and dialogue design toolkits. We needed to develop a metric for evaluating such systems in terms of their ability to handle information exchange, that is, to quantify the degree of understanding present in a system or allowed for by the tools in a design kit.

We needed to find a computationally viable way of representing the process of information exchange in the kind of dialogues we are concerned with and to test this by annotating sample dialogues and instructional texts.

Final versions of deliverables on these topics are scheduled for February, 1999 after the completion of the first year of the project. This work will position us for the building of a computational model and implementation.

Market prospects: scenarios
We are mainly concentrating on the Autoroute Scenario (of the three we are concerned with). It is a route planning task for which we have a working (keyboard input) dialogue system at SRI Cambridge.

The application that actually plans the route (`Autoroute') is a commercially available PC software package distributed free by many suppliers bundled as part of Windows. The Autoroute scenario is typical of those for which implementations of spoken dialogue systems are commercially attractive: the task involves acquiring certain pieces of information - too many to be displayed as menu items - and then optionally some further details which can then be used to interrogate an application information system.

Several projects within Europe have been looking at on-board navigation aids as an attractive and useful feature for the car of the future, and some simple commercial voice-driven navigation aids are already available. Voice operation has obvious advantages in the driver's situation.

Market prospects: current dialogue systems
In surveying current dialogue systems and toolkits we focussed on how and to what extent they are sensitive to the current dialogue context, and how and to what extent they can use dialogue in furthering the user's objectives.

The commercially most advanced of the systems we looked at, Nuance's Dialog Builder application, is a means for declaring who can speak on the basis of generating or recognizing predefined utterances. Making a proactive contribution requires one to have aims and objectives relating to the conversation based on representations of information already exchanged. The Trains system is the most complex of those we looked at in this respect and the system continually attempts to infer the user's overall plan.

The choice currently is between robust systems with little or no attempt at understanding and knowledge intensive systems which are limited by their brittleness. There is a need for robust technology enhanced by representations of information that will aid systems to make proactive contributions in limited task oriented dialogues.

Technology outlook and innovative features:
dialogue moves and information states
Why do people engaged in a dialogue say what they say when they say it and what effect do their contributions have on the information available to the participants in the dialogue? These are central questions for the automation of dialogue.

Machines need to have simple strategies that simulate aspects of human dialogue behaviour. The strategies need to be simple enough to be computationally robust and yet complex enough to make the dialogues coherent and not too irritating for the user. The simplest strategies involve just producing particular utterances in sequence or directly computing a response on the basis of the preceding utterance from the user. A common more sophisticated approach is to treat dialogues as games and utterances as instantiations of a limited set of moves (such as question, answer, clarification, request, confirmation, etc.). Allowable moves can be specified in terms of transition networks.

Our approach is to enhance this conception by associating with dialogue moves representations of the information that the dialogue participants have. The main effect of an utterance is to change this information in some way, and the information is used by the participants to decide what to do next.

Technology outlook and innovative features:
underspecification and robustness
Natural language is multiply ambiguous, and disambiguation is one of the hardest and most expensive tasks in language understanding. However, disambiguation is not always required. Often the information relevant to the current state of the dialogue is common to all the readings of a dialogue contribution and it is not necessary for the dialogue participant to resolve the ambiguity. Tools for the representation of underspecified information about meaning and techniques for disambiguation on demand were explored and developed in the FraCaS project and we are investigating how these tools can be used to enhance the computational model of information state revision.

Even with underspecified interpretation, classical interpretation techniques lead to brittle systems which are unusable on free natural language input. We are investigating how robust techniques like finite state technology can be applied to or combined with semantic processing. For example, it may be possible to characterize transitions over information states with finite state machines.

User Group, Promotion and Awareness
The project has created an International Consultation and User Group (ICUG). Currently the group has 25 members (11 of whom are from industry). We plan to increase the membership during the second year of the project. We welcome unsolicited expressions of interest in joining this group.

All members of the ICUG will be invited to the two public workshops which the project will organize at which project work and plans for the future will be presented. These workshops will include invited speakers external to the project and members of the TRINDI ICUG will be invited to comment on the progress and future plans of the project.

The first of these workshops has been scheduled for 6th May, 1999 and will be held in conjunction with Amstelogue'99 (Amsterdam Workshop on the Semantics and Pragmatics of Dialogue), Amsterdam, 7th-9th May. We have chosen to do this in order to maximize the number of people who will be able to attend our workshop.

Selected members of the ICUG will be invited to consortium meetings for which their expertise is of particular relevance and some members of the ICUG will be invited to work with the project on particular tasks.

In addition project participants have made regular contributions to international specialist conferences during the year.

Future work
Deliverables associated with the work described in this report will be completed in February, 1999 and will be made publically available on the web and in hard copy.

Work scheduled for the second year of the project (beginning February, 1999) includes the building of a dialogue move engine to illustrate how representations of information states can be associated with dialogue moves and assist in the determination of next moves. We will also present the theory that underlies this and give an overview of the practical possibilities for ways of representing information states and the kind of information that can be included.

Progress will also be underway towards results that are to be presented in the final six months of the project in February and May 2000 including prosodic clues to information structure and the representation of focus in information states.

Further information
Further information about the project can be obtained on the TRINDI web page or from the project coordinator:

Coordinator
Robin Cooper
Email
trindi@ling.gu.se
Tel.
+46-31-773-2536
Fax
+46-31-773-4853
Mail
TRINDI Administrator, Department of Linguistics, Göteborg University, Box 200, S-405 30 Göteborg, Sweden