rapaport@sunybcs (William J. Rapaport) (09/14/87)
STATE UNIVERSITY OF NEW YORK AT BUFFALO
GRADUATE GROUP IN COGNITIVE SCIENCE
ALEXANDER NAKHIMOVSKY
Department of Computer Science
Colgate University
THE REPRESENTATION AND PROCESSING OF NARRATIVES
A narrative is a text with the following properties: (a) it is produced
by one discourse participant (narrator); (b) it contains descriptions of
situations evolving or persisting in time (I call them history-tokens,
or h-tokens for short); (c) the time of a narrated h-token is determined
with respect to the previously narrated h-tokens, and usually without
reference to the time of discourse. In contrast to a conversation, the
content of a narrative is decoupled from the linear progression of its
text and unfolds in its own, separate timeline. Two structures are thus
needed to represent a narrative: the Linear Text Structure (LTS), whose
components are linked by rhetorical relations such as elaboration,
resumption or flashback; and the Event-Situation Structure (ESS), whose
components show the entire range of coherence and temporal relations. I
hypothesize that in constructing the ESS, the rhetorical relations
within it need not be recognized, although some LTS information is made
available to the processing model in the form of heuristics for manipu-
lating the WHEN-point of the Deictic Center, which I call the temporal
focus.
I adopt the following model of narrative processing. Next to ESS and
LTS, there is a short-term memory structure called Current Focus Space
(CFS) and a buffer in which the representation of the current sentence
is assembled. Among the components of the CFS are the Deictic Center
and the data structures needed for comprehension of definite anaphora.
As each new sentence is processed, one of two things happens: either
the representation of the sentence is incorporated in the CFS, with the
focusing mechanisms appropriately modified, or, in case of a focus
shift, the contents of the CFS are incorporated into the ESS and LTS,
and the CFS is completely reset. In terms of linguistic structure, the
sentence continues the same, or starts a new, discourse segment (DS).
The subject of the talk is, mostly, the time-related factors (grammati-
cal, lexical, and extra-linguistic) that help recognize a shift to a new
DS.
Monday, September 21, 1987
4:15 P.M.
Baldy 684
There will be an informal discussion with Dr. Nakhimovsky on Monday
evening at a time and place to be announced. Call Bill Rapaport (Dept.
of Computer Science, 636-3193 or 3181) or Gail Bruder (Dept. of Psychol-
ogy, 636-3676) for further information.
William J. Rapaport
Assistant Professor
Dept. of Computer Science, SUNY Buffalo, Buffalo, NY 14260
(716) 636-3193, 3180
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