dc.contributor.advisor | Bundy, Alan | en |
dc.contributor.author | Mellish, Christopher Stuart | en |
dc.date.accessioned | 2013-04-03T15:02:25Z | |
dc.date.available | 2013-04-03T15:02:25Z | |
dc.date.issued | 1981 | |
dc.identifier.uri | http://hdl.handle.net/1842/6616 | |
dc.description.abstract | A computer program which can "understand" natural language texts must
have both syntactic knowledge about the language concerned and
semantic knowledge of how what is written relates to its internal
representation of the world. It has been a matter of some controversy
how these sources of information can best be integrated to translate
from an input text to a formal meaning representation. The
controversy has concerned largely the question as to what degree of
syntactic analysis must be performed before any semantic analysis can
take place. An extreme position in this debate is that a syntactic
parse tree for a complete sentence must be produced before any
investigation of that sentence's meaning is appropriate. This
position has been criticised by those who see understanding as a
process that takes place gradually as the text is read, rather than
in sudden bursts of activity at the ends of sentences. These people
advocate a model where semantic analysis can operate on fragments of
text before the global syntactic structure is determined - a strategy
which we will call early semantic analysis.
In this thesis, we investigate the implications of early semantic
analysis in the interpretation of noun phrases. One possible approach
is to say that a noun phrase is a self-contained unit and can be
fully interpreted by the time it has been read. Thus it can always be
determined what objects a noun phrase refers to without consulting
much more than the structure of the phrase itself. This approach was
taken in part by Winograd [Winograd 72], who saw the constraint that
a noun phrase have a referent as a valuable aid in resolving local
syntactic ambiguity. Unfortunately, Winograd's work has been
criticised by Ritchie, because it is not always possible to determine
what a noun phrase refers to purely on the basis of local
information. In this thesis, we will go further than this and claim
that, because the meaning of a noun phrase can be affected by so many
factors outside the phrase itself, it makes no sense to talk about
"the referent" as a function of -a noun phrase. Instead, the notion
of "referent" is something defined by global issues of structure and
consistency.
Having rejected one approach to the early semantic analysis of noun
phrases, we go on to develop an alternative, which we call
incremental evaluation. The basic idea is that a noun phrase does
provide some information about what it refers to. It should be
possible to represent this partial information and gradually refine it as relevant implications of the context are followed up. Moreover,
the partial information should be available to an inference system,
which, amongst other things, can detect the absence of a referent and
provide the advantages of Winograd's system. In our system, noun
phrase interpretation does take place locally, but the point is that it does not finish there. Instead, the determination of the meaning
of a noun phrase is spread over the subsequent analysis of how it
contributes to the meaning of the text as a whole. | en |
dc.contributor.sponsor | SRC Postgraduate Studentship, | en |
dc.contributor.sponsor | SRC grants B/RG 94493 and GR/A 57954 | en |
dc.language.iso | en | |
dc.publisher | The University of Edinburgh | en |
dc.relation.hasversion | Bundy, A., Byrd, L., Luger, G., Mellish, C. and Palmer, M. Solving Mechanics Problems using Meta-Level inference. In Procs of the Sixth International Joint Conference on Artificial Intelligence. IJCAI, 1979. | en |
dc.relation.hasversion | Mellish, C.S. Preliminary Syntactic Analysis and Interpretation of Mechanics Problems Stated in English. Working Paper 48, Dept of Artificial Intelligence, University of Edinburgh, 1978. | en |
dc.subject | Computational linguistics | en |
dc.subject | Natural language processing | en |
dc.subject | Semantics | en |
dc.subject | Data processing | en |
dc.title | Coping with Uncertainty: Noun Phrase Interpretation and Early Semantic Analysis | en |
dc.type | Thesis or Dissertation | en |
dc.type.qualificationlevel | Doctoral | en |
dc.type.qualificationname | PhD Doctor of Philosophy | en |