Says who?
On the treatment of speech attributions
in discourse structure
Gisela Redeker & Markus Egg
University of Groningen
Overview
• Speech and thought in discourse
• Attribution in Carlson & Marcu (2001)
• Discourse structures as trees
• Problems with Carlson & Marcu’s treatment
• Our proposal
• Conclusions
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Reporting speech and thought
• Direct speech and thought
– He said: “Yes, I’ll come to the party.”
– He thought: “Yes, I’ll go to the party.”
• Indirect speech and thought
– He said he’d come to the party.
– He thought he’d go to the party.
• Not considered here:
Description of speech acts or thought contents
– He promised to come to the party.
– He pledged attendance.
– He meant to go to the party.
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Attribution of speech and thought
• Indicators of attribution include:
– Speech verbs (say, tell, state, suggest, point out, ask, promise,
advise, etc.)
– Specialised expressions like English according to, Dutch volgens,
or German zufolge; in informal conversational English also go
and be like.
– Cognitive predicates (think, believe, know, suppose, hope, fear,
estimate, expect, see, etc.)
Note: Cognitive predicates are often used in reporting a
speaker’s disclosure of thoughts or feelings (he thinks/hopes
instead of he said: “I think/hope …”)
• Attribution phrases can occur before, in between, or after
the reported material.
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Representing reported discourse in the
discourse structure
•
Reported speech and thought can be used to
a) introduce the reported propositional contents into the current
discourse (with the attribution as a mere acknowledgement of
the source)
b) talk about the fact that someone (the agent in the attribution
phrase) has said or thought something (and then e.g.
contrasting it to someone else’s opinion)
•
•
In Rhetorical Structure Theory (RST) this difference
could be represented by assigning nuclear status to the
attributed material in case (a) and to the attribution
phrase in case (b).
Problem: This is not a clear-cut, decidable distinction
and thus cannot be the basis for assigning nuclearity.
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Attribution in Carlson & Marcu (2001)
Carlson and Marcu (2001) define an ATTRIBUTION
relation that always assigns nuclear status to the
attributed material, with the attribution phrase as the
satellite. That is, they model case (a) above.
In RST-format, that looks like these two examples:
(1)
1-2
Attribution
(2)
1-2
The legendary GM
chairman declared
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that his company would
make "a car for every
purse and purpose."
Attribution
The shares represented
66% of his Dun &
Bradstreet holdings,
according to the
company.
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Attribution in Carlson & Marcu (2001)
• The ATTRIBUTION relation applies to direct and indirect
speech and thought. For indirect reports (like example
(1)), the nuclearity assignment thus goes against the
syntactic intuition that a complement clause has
subordinate status.
• The definition includes belief attributions (which in news
reports are usually based on speech). Note that the
attribution satellite here not only specifies a source, but
introduces an opaque context within which the reported
material has to be interpreted.
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Attribution in Carlson & Marcu (2001)
• Excluded are cases where the attribution phrase does
not specify a source (those phrases are not analysed as
separate segments).
This is in line with the idea that attribution is essentially
acknowledgement of a source, but ignores the opacity of
belief contexts. It also introduces yet another semantic
criterion in the (otherwise mostly syntactically motivated)
segmentation rules.
• Serious problems arise when the reported material
consists of more than one atomic segment (Wolf &
Gibson 2005).
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Excursus: Discourse structures as trees
• We assume that discourse has a hierarchical
structure in which clause-like atomic segments
combine into larger discourse segments.
• We model discourse structure as binary trees
(but compare our representations to classic RST
which allows multi-satellite structures; see Egg &
Redeker (fc) for a discussion).
• Right frontier constraint (RFC): Treeness implies
that only segments in the right frontier of the
discourse (in RST: the last segment or the last
nucleus) are available for attachment.
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Problem 1 for Carlson & Marcu (2001)
(3)
1-4
Condition
1-3
Attribution
(1) As long as we believe
(4) our political map should
reflect our belief.
2-3
Conjunction
(2) that all Americans, of every
(3) and can live together
race and ethnic background,
cooperatively,
have common interests
C1 is inaccessible for C4 because of the RFC and thus
attaches to C1-C3, yielding the implausible interpretation
that C4 is more closely related to the nucleus C2-C3 than
to the satellite C1.
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Problem 2 for Carlson & Marcu (2001)
(4)
1-4
Condition
(C4) “As long as the
trucks and the timid
stay out of the left
lane.”
1-3
Attribution
(C1) “Sure I’ll be polite,”
2-3
Elaboration
(C2) promised one
BMW driver
(C3) who gave his
name only as Rudolph.
For sentence-final attribution phrases, the representation
cannot distinguish between a continuation of the quote and
a continuation like (C4’), which is not part of the quote:
(C4’)
He greeted and drove off with screeching tyres.
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Our Proposal
i.
Represent attribution phrases as nuclei and
the attributed material as satellites.
ii. Move sentence-medial and sentence-final
attribution phrases to the front of the sentence
to allow for the integration of additional
attributed material.
iii. Use an underspecified representation format
to allow for uncertainty and ambiguity about
the scope of the attribution.
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Our Proposal: (i) Nuclearity
• By assigning nuclear status to the attribution phrase and
introducing the attributed material as its satellite, we
solve problem 1, as the attribution phrase now remains
at the right frontier and is thus available for attachment.
(5)
1-4
Condition
1-3
(4) our political map
should reflect our
belief.
Attribution
(1) As long as we
believe
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2-3
Conjunction
(2) that all
(3) and can live
Americans, of every
together
race and ethnic
cooperatively,
background, have
common interests
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Our Proposal: (ii) Order of Segments
• The reversed nuclearity assignment does not solve the
problem of attribution phrases that are preceded and
followed by attributed material (problem 2).
• We could represent the fact that the continuation after
the attribution phrase is still part of the quote, but not
how the quote parts are related:
(6)
1-4
Attribution
(C1) “Sure I’ll be
polite,”
Attribution
2-3
Elaboration
(C2) promised one
BMW driver,
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(C3) who gave his
name as Rudolph.
(C4) “As long as the
trucks and the timid
stay out of the left
lane.”
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Our Proposal: (ii) Order of Segments
• We propose to move all attribution phrases to the
beginning of the sentence they occur in. In this way,
both the attribution phrase and the attributed material
remain at the right frontier and are thus available for
continuation, allowing the quotation segments to be
related:
(7)
1-4
Attribution
1-2
3-4
Elaboration
(C2) promised one
BMW driver,
(C3) who gave his
name as Rudolph.
Condition
(C1) “Sure I’ll be
polite,”
(C4) “As long as the
trucks and the timid
stay out of the left
lane.”
• The range of the attributed material can now be
specified exactly in terms of the satellite.
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Our Proposal: (iii) Underspecification
Where the range of the attributed material is not explicitly
marked, world knowledge or pragmatic inference may be
required, which may not be readily available. The text
may also be genuinely ambiguous as in (6) .
(6) The market makers say (C1) they aren’t comfortable carrying big
positions in stocks (C2) because they realize (C3) prices can tumble
quickly (C4). (wsj_1142)
An underspecified representation as proposed e.g. in
Egg & Redeker (to appear) allows a representation that
leaves the range of the attribution relation unspecified.
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Conclusions
• Representing attribution phrases as satellites
(as proposal by Carlson & Marcu 2001) leads to
problems in a representation that assumes
treeness of discourse structures.
• Our proposal can handle those problems while
allowing representation of discourse structures
as binary trees.
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