This file contains bibliographic citations and links to some of my recent papers. Most citations are stored as compressed (or gzipped) postscript files. After a short list, the citations are also listed with abstracts and FTP addresses. Most citations end with the name of a compressed (or gzipped) postscript file.
ftp.cs.rochester.edu
in directory
pub/papers/ai
, unless otherwise noted.
Defining an utterance unit in spoken dialogue has remained a difficult issue. To shed light on this question, we consider grounding behavior in dialogue, and examine co-occurrences between turn-initial grounding acts and utterance unit signals that have been proposed in the literal, namely prosodic boundary tones and pauses. Preliminary results indicate high correlation between grounding and boundary tones, with a secondary correlation for longer pauses.
We explore grounding and the sub-phenomena of miscommunication and repair from both theoretical and empirical perspectives. From a theoretical perspective, we classify several types of miscommunication, as action or perception failure, and part of a more general case of non-alignment of the mental states of agents. From an empirical perspective, we present a preliminary analysis of examples of miscommunication in multi-modal collaboration. These points of view converge towards a predictive model of grounding, which considers costs and benefits of performing grounding acts (including repairs of miscommunication).
In order to make spoken dialogue systems more sophisticated, designers need to better understand the conventions that people use in structuring their speech and in interacting with their fellow conversants. In particular, it is crucial to discriminate the basic building blocks of dialogue and how they affect the way people process language. Many researchers have proposed the {\em utterance unit} as the primary object of study, but defining exactly what this is has remained a difficult issue. To shed light on this question, we consider grounding behavior in dialogue, and examine co-occurrences between turn-initial grounding acts and utterance unit signals that have been proposed in the literal, namely prosodic boundary tones and pauses. Preliminary results indicate high correlation between grounding and boundary tones, with a secondary correlation for longer pauses. We also consider some of the dialogue processing issues which are impacted by a definition of utterance unit.
Designing an agent to participate in natural conversation requires more than just adapting a standard agent model to perceive and produce language. In particular, the model must be augmented with social attitudes (including mutual belief, shared plans, and obligations) and a notion of discourse context. The dialogue manager of the TRAINS-93 NL conversation system embodies such an augmented theory of agency. This paper focuses on the representation of mental state and discourse context and the deliberation strategies used in the agent model of the dialogue manager.
Natural language dialogue systems require contextual information for a variety of processing functions, including reference resolution, speech act recognition, and dialogue management. While much has been written about individual contextual problems, many of the proposed representations are mutually incompatible, unusable by the agents involved in a conversation, or both.We present a model of context that tries to reconcile in a general and systematic fashion the differences between the discourse models used for reference resolution, conversation act recognition, and dialogue management in a system dealing with conversations. Starting from the technical solutions adopted in DRT, we show first of all how to obtain a discourse model that while preserving DRT's basic ideas about referential accessibility, includes information about the occurrence of speech acts and their relations. We show then how the information about speech acts can be used to formalize the basic ideas of Grosz and Sidner's model of discourse structure. Finally, we extend this model to incorporate an account of the grounding process.
The process of adding to the common ground between conversational participants (called grounding) has previously been either oversimplified or studied in an off-line manner. This dissertation presents a computational theory, in which a protocol is presented which can be used to determine, for any given state of the conversation, whether material has been grounded or what it would take to ground the material. This protocol is related to the mental states of participating agents, showing the motivations for performing particular grounding acts and what their effects will be.We extend speech act theory to account for levels of action both above and below the sentence level, including the level of grounding acts described above. Traditional illocutionary acts are now seen to be multi-agent acts which must be grounded to have their usual effects.
A conversational agent model is provided, showing how grounding fits in naturally with the other functions that an agent must perform in engaging in conversation. These ideas are implemented within the TRAINS conversation system.
Also presented is a situation-theoretic model of plan execution relations, giving definitions of what it means for an action to begin, continue, complete, or repair the execution of a plan. This framework is then used to provide precise definitions of the grounding acts in terms of agents executing a general communication plan in which one agent must present the content and another acknowledge it.
We present a situation theoretic formalization of plan execution which allows for an abstract characterization of the role an action performance plays in the execution of a plan, including characterizations of performance error and plan repair. The Plan Execution Situation presented generalizes the mental state of having a plan to include cases where the plan is in the midst of execution, and allows for representation of dynamic change of the plan's recipe as well as the attitudes of the agent towards previous execution. We also show how this formalism can be used in different plan inference tasks such as plan execution monitoring and plan recognition.
We show that in modeling social interaction, particularly dialogue, the attitude of obligation can be a useful adjunct to the popularly considered attitudes of belief, goal, and intention and their mutual and shared counterparts. In particular, we show how discourse obligations can be used to account in a natural manner for the connection between a question and its answer in dialogue and how obligations can be used along with other parts of the discourse context to extend the coverage of a dialogue system.
Keywords: TRAINS; spoken language corpus; task-oriented dialogue; conversation.
Keywords: speech acts; conversation; literal meaning; discourse; grounding;
turn taking.
The resulting notion of Conversation Acts is more general than
speech act theory, encompassing not only the traditional speech acts
but turn-taking, grounding, and higher-level argumentation acts as well.
Furthermore, the traditional speech acts in this scheme become fully joint
actions, whose successful performance requires full listener participation.
This paper presents a detailed analysis of spoken language dialogue.
It shows the role of each class of conversation acts
in discourse structure, and discusses how members of each class
can be recognized in conversation. Conversation acts, it will be seen,
better account for the success of conversation than speech act theory alone.
The TRAINS project is an effort to build a conversationally
proficient planning assistant. A key part of the project is the
construction of the TRAINS system, which provides the research
platform for a wide range of issues in natural language
understanding, mixed-initiative planning systems, and representing
and reasoning about time, actions and events. Four years have now
passed since the beginning of the project. Each year we have
produced a demonstration system that focused on a dialog that
illustrates particular aspects of our research. The commitment to
building complete integrated systems is a significant overhead on
the research, but we feel it is essential to guarantee that the
results constitute real progress in the field. This paper describes
the goals of the project, and our experience with the effort so far.
94.traum-et-al.aaai-spring-94.integrating-nlu-trains.ps.Z
This paper describes the TRAINS-93 Conversation System, an
implemented system that acts as an intelligent planning assistant
and converses with the user in natural language. The architecture of
the system is described and particular attention is paid to the
interactions between the language understanding and plan reasoning
components. We examine how these two tasks constrain and inform
each other in an integrated NL-based system.
This paper contains an investigation of the relationship between
rhetorical relations and intentions. Rhetorical relations are claimed
to be actions, and thus the proper objects of intentions, although
some relations may occur be independent of intentions. Explicit
identification of particular relations is shown to be not always
necessary when this information can be captured in other ways,
nevertheless, relations are often useful both in planning and
recognition.
Task description: 92.tn1.trains_91_dialogues.ps.Z
Plain text dialogues: 92.tn1.trains_91_dialogues.txt
This report contains a small corpus of transcriptions of task oriented
spoken conversations in the TRAINS domain. Included are 16 conversations,
amounting to over 80 minutes of speech. Also included are a description
of the task and collection situation and the conventions used in
transcription and utterance segmentation.
This paper describes the dialogue manager of the TRAINS-92 system.
The general dialogue model is described with emphasis on the
mentalistic attitudes represented.
A linguistic form's compositional, timeless meaning can be surrounded
or even contradicted by various social, aesthetic,
or analogistic companion meanings.
This paper addresses a series of problems in the structure of
spoken language discourse, including turn-taking and grounding.
It views these processes as composed of fine-grained actions,
which resemble speech acts both in resulting from a computational
mechanism of planning and in having a rich relationship to the
specific linguistic features which serve to indicate their presence.
We propose that Grounding, the process of achieving mutual
understanding between participants in a conversation, be analyzed in
terms of the actions performed by the conversants which contribute to
achieving this mutual understanding. We propose a set of
Grounding Acts which facilitate this analysis. This paper describes
Grounding Acts, and a ``grammar'' stipulating which series of
performance of grounding acts result in grounded content.
A general purpose reasoning agent may come in contact with many
types of external forces which have differing types of effects on the
world. Different types of forces require different types of reasoning
about them. We present a classification scheme for planning domains,
based on differentiating the types of causative forces present along
dimensions of the degree of interaction and of how cognitive they are.
We present some speculations on how best to reason in these domains.
Example problems are illustrated using the ARMTRAK domain.
Last Update: 24 May 1996 / David Traum / David.Traum@tecfa.unige.ch