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Newsletter, Nov. 29, Vol.2 No. 6





                       C S L I   N E W S L E T T E R
___________________________________________________________________________
November 29, 1984               Stanford                      Vol. 2, No. 6
___________________________________________________________________________

         A weekly publication of The Center for the Study of Language and 
	 Information, Ventura Hall, Stanford University, Stanford, CA 94305
                           ____________ 

         CSLI ACTIVITIES FOR *THIS* THURSDAY, NOVEMBER 29, 1984

12 noon                 TINLunch
  Ventura Hall          Title to be announced
  Conference Room       Discussion led by Lauri Carlson
				
2:15 p.m.               CSLI Seminar
  Redwood Hall          ``Parsing Acoustic Events''
  Room G-19              by Meg Withgott
                        Discussant will be Alex Pentland. 
                        (Abstract on page 2)

3:30 p.m.               Tea
  Ventura Hall		

4:15 p.m.               CSLI Colloquium
  Redwood Hall          No colloquium today.
                           ____________ 

                SCHEDULE FOR ***THURSDAY, DECEMBER 6,*** 1984

12 noon                 TINLunch
  Ventura Hall          ``Syntactic Features, Semantic Filtering,
  Conference Room       and Generative Power''
                        Discussion led by Peter Sells
                        (Abstract on page 2)

2:15 p.m.               CSLI Seminar
  Redwood Hall          ``The Structures of Discourse Structure''
  Room G-19             by Barbara J. Grosz
                        Discussant will be Ray Perrault.
                        (Abstract on page 2)

3:30 p.m.               Tea
  Ventura Hall		

4:15 p.m.               CSLI Colloquium
  Redwood Hall          Discussion of DOD Funding
  Room G-19             Donald Kennedy, President, Stanford
                        Sydney Drell, Dep. Dir., SLAC
                        John Etchemendy, discussion leader
                           ____________ 

        *****THURSDAY CSLI ACTIVITIES BETWEEN QUARTERS*****
There will be no center-wide Thursday activites between quarters (on
December 20, 27, and January 3). Regular Thursday activities will resume
on January 10.
Page 2                   CSLI Newsletter                  November 29, 1984
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                   ABSTRACT OF TODAY'S SEMINAR
                   ``Parsing Acoustic Events''

This seminar addresses the problem of formulating a language-independent
representation of the acoustic aspects of natural, continuous speech from
which a general parser using language-specific grammars can recover
linguistic structure.  This decomposition of the problem permits a
representation that is stable over utterance situations and provides
constraints that handle some of the difficulties associated with partially
obscured or ``incomplete'' information. A system will be described which
contains a grammar for parsing higher-level (phonological) events as well
as an explicit grammar for low-level acoustic events. It will be shown that
the same techniques for parsing syntactic strings apply in this domain.  The
system thus provides a formal representation for physical signals and a way
to parse them as part of the larger task of extracting meaning from sound.
                                              --Meg Withgott
                           ____________ 

                ABSTRACT OF NEXT WEEK'S SEMINAR
           ``The Structures of Discourse Structure''

This talk will introduce a theory of discourse structure that attempts to
answer two rather simple questions, namely: What is discourse? What is
discourse structure? In this work (being done jointly with Sidner at BBN)
discourse structure will be seen to be intimately connected with two
nonlinguistic notions--intention and attention. Intentions will be seen to
play a primary role not only in providing a basis for explaining discourse
structure, but also in defining discourse coherence, and providing a coherent
notion of the term ``discourse'' itself.  A main thesis of the theory is that
the structure of any discourse is a composite of three interacting
constituents: the structure of the actual sequence of utterances in the
discourse, a structure of intentions, and an attentional state. Each of these
constituents of discourse structure both affects and is affected by the
individual utterances in the discourse.  The separation of discourse
structure into these three components allows us to generalize and simplify a
number of previous results and is essential to explaining certain discourse
phenomena. In particular, I will show how the different components contribute
to the proper treatment of various kinds of interruptions, as well as to
explanations of the use of certain types of referring expressions and of
various expressions that function directly to affect discourse structure.
                                        --Barbara J. Grosz
                        ____________

                  ABSTRACT OF NEXT WEEK'S TINLUNCH
    Syntactic Features, Semantic Filtering, and Generative Power

There is a trade-off in linguistic description using grammars with a syntax
and a separate semantics, such as GPSG.  One can often either use a
syntactic feature or appeal to semantic filtering to achieve the same ends.
Current GPSG countenances no semantic filtering, i.e. does not overgenerate
strings in the syntax and then let the semantics throw some away as
`uninterpretable'.  In the Tinlunch I would like to discuss this position
in light of some work I did in my dissertation which looks like it requires
semantic filtering, and in light of a paper by Marsh & Partee which shows
that adding certain types of semantic filtering to a grammar greatly
increases the generative power.                  --Peter Sells
Page 3                   CSLI Newsletter                  November 29, 1984
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                           AREA P LECTURE
                ``Parallel  distributed  processing:
              New  explanations  for language behavior''

Jeff Elman (Department of Linguistics, UCSD)
December 11, 1984, 11.00 A.M.
Ventura Hall Conference Room

ABSTRACT:  Many students of human behavior have assumed that it is fruitful
to think of the brain as a very powerful digital computer. This metaphor
has had an enormous impact on explanations of language behavior. In this
talk I will argue that the metaphor is incorrect, and that a better
understanding of language is gained by modelling language behavior with
parallel distributed processing (PDP) systems.  These systems offer a more
appropriate set of computational operations, provide richer insights into
behavior, and have greater biological plausibility.  I will focus on three
specific areas in which PDP models offer new explanations for language
behavior:
   (1) the ability to simulate rule-guided behavior without explicit rules;
   (2) a mechanism for analogical behavior; and
   (3) explanations for the effect of context on interpretation and for
       dealing with variability in speech.
Results from a PDP model of speech perception will be presented.
                         ____________

            SEMINAR IN LOGIC AND FOUNDATIONS OF MATHEMATICS

Speaker: Prof. Rolando Chuaqui, Catholic University of Chile and IMSSS
Title:   A Semantical Definition of Probability
Place:   Room 381-T, 1st floor Math. Corner
Time:    Monday, December 3, 4:15-5:30 p.m.

ABSTRACT:  The analysis proposed in this lecture is an attempt to formalize
both chance and degree of support.  Chance is considered as a dispositional
property of the objects plus the experimental conditions (i.e. what is
called the chance set-up).  Degree of support measures the support that the
evidence we have (i.e. what we accept as true) gives to propositions.
Chance, in this model, is determined by the set K of possible outcomes (or
results) of the chance set-up.  Each outcome is represented by a relational
structure of a certain kind.  This set of structures determines the algebra
of events, an algebra of subsets of K, and the probability measure through
invariance under a group of symmetries.  The propositions are represented
by the sentences of a formal language, and the probability of a sentence,
phi in K, P[K](phi), is the measure of the set of models of phi that are
in K.   P[K](phi) represents the degree of support of phi given K.  This
definition of probability can be applied to clarify the different methods
of statistical inference and decision theory.

Page 4                   CSLI Newsletter                  November 29, 1984
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            CSLI WORKSHOP ON THE SEMANTICS OF PROGRAMS

Tuesday, December 4, 1984
Location: The Bach Dancing and Dynamite Society, Princeton CA
          (a suburb of Half-Moon Bay)

There are long-standing traditions for the study of natural language
semantics and CSLI projects have been extending and reinterpreting them.
There is a briefer, but substantial, tradition for the study of the
semantics of programming languages.  Over the past few months, there have
been a series of presentations and discussions about similarities and
differences between the semantic accounts of natural and computational
languages.  Theories of natural language semantics have raised a number of
issues.  The purpose of the workshop is to discuss how some of these
theories can give rise to better accounts of the relation between
programs/program executions and the world.  Participation in the workshop
is by invitation only.  If you are interested in being invited to the
workshop, contact Ole Lehrmann Madsen (Madsen at SU-CSLI). If you have any
questions regarding the workshop you may contact Terry Winograd (TW at
SU-SAIL) or Madsen.
                         ____________

                        PH.D. PROPOSAL

On Tuesday, December 4, from 3:15 p.m. to 5:05 p.m., in Bldg. 200-217, Kurt
Queller will talk about ``Active Exploration with syntagmatic routines in
the child's construction of grammar:  Some phonological perspectves.'' Based
on detailed longitudinal analysis of data from 3 one-year-olds, the proposed
dissertation will provide a typology of syntag-matic phonological routines
or ``word-recipes'' used by young children in bulding a repertoire of
pronounceable works.  Then, it will show how individual children exploit
particular combinations of routines in constructing a coherent phonological
system.  Extensive synchronic variability and changes over time will be
accounted for in terms of the chld's systematic exploration of the options
implicit in the resulting system.

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