From: wardk@ogicse.cse.ogi.edu (Karen Ward)
Newsgroups: misc.jobs.offered.entry
Subject: Beaverton, OR 97006, FT/TMP/INT, Comp Ling research@Oregon Graduate Institute
Date: 20 Aug 92 20:48:26 GMT
Article-I.D.: ogicse.41746
Distribution: pnw
Organization: Oregon Graduate Institute (formerly OGC), Beaverton, OR

Position:	Full time temporary (10 week) internship in natural language
		processing or computational linguistic research.

Time Frame: 	Fall term 1992.  Exact start date is flexible.

Contact: 	email:   novick@cse.ogi.edu

		US mail: David Novick
  			 Department of Computer Science and Engineering
  			 Oregon Graduate Institute
  			 19600 N.W. von Neumann Drive
  			 Beaverton, OR, 97006-1999

Mandatory Requirements:   Must be an undergraduate college student.
	
Qualifications:	 Familiarity with the Unix environment, and some background
		 in linguistics, computational linguistics or natural
		 language processing.

Salary:		$10/hr for 10 weeks




DETAILED POSITION DESCRIPTION:

We have a full-time research internship available fall term (1992) for an
undergraduate student interested in natural language processing and/or
computational linguistics.  The position is for ten weeks at $10 per
hour; the start date is flexible.  It is funded by the National
Science Foundation under the Research Experience for Undergraduates
Program.  The research project involves pragmatic models of pause in
spontaneous dialogue.  A discussion of the research is appended below.

The position requires

  (1) familiarity with the Unix environment, and
  (2) some background in linguistics, computational linguistics or
      natural language processing.

The intern will perform syntactic and pragmatic analyses of the
labeled utterances and may label additional utterances as required.
Skills in statistical methods and computer programming would be
helpful.

Note:  This position is available only for undergraduate students.
This internship is designed to introduce an undergraduate to research
life and practices; we hope to interest the student in a research
career in natural language processing.  The intern will be fully
integrated into the research life of the Interactive Systems
Laboratory at OGI, where we have a number of ongoing dialogue and
spontaneous speech projects underway.

To apply for the internship, please send

  (1) a brief statement of the reasons for your interest,
  (2) the date you would prefer to start work, and
  (3) a current curriculum vita

via email to novick@cse.ogi.edu or via US mail to

  David Novick
  Department of Computer Science and Engineering
  Oregon Graduate Institute
  19600 N.W. von Neumann Drive
  Beaverton, OR, 97006-1999


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	  Pragmatic Models of Pause in Spontaneous Dialogue
				   
			     David Novick
		      Oregon Graduate Institute

			       Summary

This research investigates characteristics and uses of pause in
spontaneous dialogue. The research grows out of a pilot study
currently underway as a joint effort at OGI and MIT.  The research is
based on and makes the following claims:

  o Spoken language understanding systems can improve their
    performance by taking advantage of systematic aspects of spontaneous
    speech phenomena.

  o Pauses (including filled pauses) have predictive value for
    machine recognition of spontaneous speech. There are regularities in
    the occurrence of pauses that depend on the particular task and thus
    depend on pragmatic rather than syntactic factors.

This work differs from previous speech-recognition research on pauses
because the proposed model is knowledge-based, relying on the function
of pauses with respect to dialogue and domain pragmatics.

			     Introduction

This research investigates the occurrence of spontaneous speech
effects (in particular, pauses-filled and unfilled), and their
relation to task-dependent, pragmatic aspects of dialogue. Just as
semantic grammars are effective for parsing word-level utterances,
pragmatic models of pause should effectively aid spoken language
understanding in ways that syntactic models cannot address.
Accordingly, we propose to produce a task-related account of pause
in the ATIS domain (Hemphill et al., 1990).

As pause is almost trivially extractable from the speech signal, one
of the goals of this research is to determine linguistic correlates of
pause, with particular attention to prediction of the consequences of
pause for speech recognition.  Wightman et al. (1991) succeed in
showing that, for a set of professionally read sentences, their
prosody model produces syntactic disambiguation equivalent to that of
human understanders.  They showed significant, systematic weaknesses
in earlier syntactic prosody models and extended them.  Similarly,
Price et al. (1991) were able to show that naive listeners can often
distinguish different meanings resulting from syntactic variation on
the basis of prosodic information.  They suggest a model of the
features used by listeners to produce this disambiguation.

However, all of these models are fundamentally syntactic.  They do not
address the pragmatic factors presented by the particular task. 
Preliminary analysis of parts of the ATIS corpus suggests that
pragmatic factors are critical:  Many of the most significant pauses
can be explained by a relatively simple task-based model that accounts
for key domain concepts.  For example, pauses are often associated with
the concepts of city of origin or destination, and may appear either
before or after prepositions associated with the cities.  That is, the
syntactic factor varies while the pragmatic factor remains predictive.

			       Approach

If we are to understand the pragmatic role of pauses in dialogue, we
must understand their contexts of use. Prior pragmatically based work
on pauses generally has been limited to conversation-analytic
techniques applied to very small corpora-typically a fragment of a
single conversation (see, e.g., Senstrom, 1987; Chafe, 1985, 1986).
Other studies of pauses or temporality in spoken language have
examined larger samples of speech but have not addressed the
theoretical concerns that underlie this inquiry. For example, Green &
Cappella (1986) proposed a model of conversational move structure that
applied to multiple utterances in monologue rather than to within-move
utterances in dialogue. Another interesting approach (O'Shaugnessy,
1991) distinguished between planned pauses and unplanned pauses.
Swingle & Hope (1987) addressed the relationship between pauses and
the general dialogue context by showing that pause patterns of one
conversant affected the pause patterns of the other; this was a
descriptive study, though, and did not relate the pause effects to
language understanding.

In contrast, this study investigates the role of pauses for much
larger corpora by using digital speech tools to relate pauses to
pragmatic dialogue factors of direct importance to language
understanding systems.  A collaborative pilot study is currently being
conducted at OGI and MIT in the context of (1) ongoing DARPA-funded
research at MIT into spontaneous speech effects and dialogue models
for the ATIS task and (2) ongoing NSF-funded research at OGI into
meta-linguistic dialogue models of conversational control.  At OGI,
we have labeled complete time-aligned utterance sets for six speakers,
with pauses and filled pauses noted and timed.

We are particularly interested in the linguistic theories of Wallace
Chafe, who relates pauses to context changes (Chafe, 1985) and
cognitive constraints on reference (Chafe, 1986). In his work, Chafe
examines rather small excerpts from naturally occurring discourse; we
plan to apply these models to a larger corpus of dialogues for which
critical elements of the context are already known. In particular, we
plan to survey the use of pauses and filled pauses in a significant
subset of the ATIS protocols, a relatively large corpus of
task-oriented dialogue (Hemphill, et al., 1990).

			      Hypotheses

For the REU project, we will investigate the following hypotheses:

  (1) Do the syntactic models of pause, produced using read speech,
  account for the pauses in spontaneous speech in the ATIS task?

  (2) Can pragmatic models of pause, using sematic grammar notions,
  account for the pauses in spontaneous speech in the ATIS task?

The undergraduate student will perform syntactic and pragmatic
analyses of the labeled utterances, and may label additional
utterances as required.

			      References

Chafe, W. (1985). Some reasons for hesitating. In Perspectives on
silence, D. Tannen & M. Saville-Troike (eds.), 77-89. Norwood, N.J.:
Ablex.

Chafe, W. (1986). Cognitive constraints on information flow. In
Coherence and grounding in discourse, R. Tomlin (ed.), 21-52.
Amsterdam: J. Benjamins.

Greene, J. O., & Cappella, J. N. (1986). Cognition and talk: The
relationship of semantic units to temporal patterns of fluency in
spontaneous speech. Language and Speech, 29(2), 141- 157.

Hemphill, C. T., Godfrey, J. J., & Doddington, G. R. (1990), The ATIS
spoken language systems pilot corpus. Proceedings of the 1990 DARPA
Speech and Natural Language Workshop.

O'Shaugnessy, D., Labelling hesitation phenomena in spontaneous
speech, Proc. 1991 IEEE Workshop on Automatic Speech Recognition,
Arden House, NY, December 1991.

Price, P., Ostendorf, M., Shattuck-Hufnagel, S., & Fong, C. (1991).
The use of prosody in syntactic disambiguation. Proceedings of the
1991 DARPA Speech and Natural Language Workshop.

Senstrom, A.-B. (1987). A study of pauses as demarcators in discourse
and syntax. Costerus, 57, 203-218.

Swingle, P. G., & Hope, G. F. (1987). Interpersonal influence on
temporal measures of vocalization in interview situations. Language
and Speech, 30(2), 159-167.

Wightman, C. W., Veilleux, N. M., & Ostendorf, M. (1991). Use of
prosody in syntactic disambiguation: An analysis-by-synthesis
approach. Proceedings of the 1991 DARPA Speech and Natural Language
Workshop.

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  David G. Novick   | Department of Computer Science and Engineering
 novick@cse.ogi.edu | Oregon Graduate Institute of Science and Technology 
 tel (503) 690-1156 | 19600 N.W. Von Neumann Drive
 fax (503) 690-1029 | Beaverton, OR 97006-1999
--------------------------------------------------------------------------

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