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T ransitivity and Foregrounding in N e w s Articles: e x p e r i m e n t s
i n i n f o r m a t i o n retrieval and a u t o m a t i c s u m m a r i s i n g
Kay and Ruth Aylett
Information Technology Institute
University of Salford
Manchester M5 4WT
2 Definition of Transitivity
T his paper describes an on-going study
w hich applies the concept of transitivity
t o news discourse for text processing tasks.
T he complex notion of transitivity is def ined and the relationship between transit ivity and information foregrounding is exp lained. A sample corpus of news articles
h as been coded for transitivity. The corpus
i s being used in two text processing experi ments.
T ransitivity is usually considered to be a property of
a n entire clause (Hopper and Thompson, 1980). It
i s, broadly, the notion that an activity is transferred
f rom an agent to a patient. It is therefore inherently
l inked with a clause containing two participants in
w hich an action is highly effective.
T he concept of transitivity has been defined in
t erms of the following parameters:
T he basic hypothesis of this study is that the degree
o f transitivity associated with a clause indicates the
l evel of importance of a clause in a narrative text.
F or this assumption to form the basis of a practical
i mplementation, transitivity must be objectively def ined and the definition must be able to be processed
T he notion of transitivity clearly has m a n y implic ations for text processing, in particular information
r etrieval and a u t o m a t i c summarising, because it can
b e used to grade information in a document accordi ng to importance. In an information retrieval cont ext, it means t h a t a transitivity index could influe nce a decision about the relevance of a document to
a q uery. In a u t o m a t i c...