Corpus-based Semantics of
Concession
Livio Robaldo
Department of Computer Science, University of Turin
robaldo@di.unito.it
Eleni Miltsakaki
Institute for Research in Cognitive Science, UPenn
elenimi@seas.upenn.edu
Alessia Bianchini
Department of Computer Science, University of Turin
alessia.bianchini84@gmail.com
The PDTB: Discourse relations
• They are conveyed by lexical items connecting two
textual spans.
Examples:
On the one hand, John loves Barolo.
So he went and ordered three cases.
On the other hand, he didn’t have much
money.
So then he had to cancel the order.
Discourse relations
On the one hand –
On the other hand
John loves Barolo.
So
he went and ordered three cases.
So
he didn’t have much money.
then
he had to cancel the order.
PDTB
The Penn Discourse Treebank is, to date, the largest
annotation effort at the discourse level (more than
40000 annotations).
• It encodes discourse relations associated with
discourse connectives.
• It includes implicit connectives. E.g.
[John broke his arm]arg1.
(implicit=so) [Now, he can’t cycle to work]arg2
• Annotations are made on the Penn Treebank,
including approximately 1 million words, taken from
the Wall Street Journal.
Sense annotation in the PDTB
Some discourse connectives can be ambiguous and
encompass more than one meaning. E.g. since:
Temporal
Since [the first fraud was discovered in July 1986
at an office of the People’s Bank of China]arg2,
[15 major cases have been found]arg1.
Causal
[It was a far safer deal for lenders]arg1 since
[NWA had a healthier cash flow and more
collateral on hand]arg2.
Aim of the sense annotation
The aim of the annotation of senses is to provide
sense tags which will flag the intended interpretation
of the connectives.
Identifying senses has proved to be a challenging
task. Fine grained or coarse grained distinctions?
Extensive sense annotation studies have been
carried out to disambiguate the meaning of verbs
(see, for example, Propbank:
http://verbs.colorado.edu/~mpalmer/projects/ace.html).
Much less for discourse connectives…
Semantic CLASSes
Semantic CLASSes
TEMPORAL
CONTINGENCY
COMPARISON
EXPANSION
Comparison CLASS Types
Comparison
Contrast
juxtaposition
opposition
Concession
expectation
contra-expectation
Concession
The Type Concession applies when:
Arg2 event/state A implies an event/state C but
 Arg1 event/state B states or implies ~C
OR
 Arg1 event/state A implies an event/state C but
 Arg2 event/state B states or implies ~C

The former is tagged as ‘expectation’, the latter as
‘counter-expectation’.
Literature on Concession
• A general defeasible rule “Beatiful women
In the literature
Rimon,
94], [Lagerwerf, 98],
usually [Winter
married ” &
holds
in the context.
[Korbayova
& rule
Webber,
07],
two cases
have been
• This
creates the
expectation
that Greta
Garbo according
married.
distinguished,
to how the expectation is
• Argd directly
denies this expectation, by
denied: directly
or indirectly.
asserting exactly the opposite.

Direct Contrast:
Although [Greta Garbo was considered
the yardstick of beauty]Argc, [she never
married]Argd.
• The concessive relation involves an intermediate
proposition, called the Tertium Comparationis
(TC) [Lagerwerf, 98], defeasibly implied by Argc
and whose negation is (non-defeasibly) implied by
In the literature
[Winter & Rimon, 94], [Lagerwerf, 98],
Argd.
[Korbayova
Webber,
07],
• In the&example
below,
the two
TC iscases
“John have
is not been
distinguished,
according
how that
the John
expectation
is
mobile”: Argc
defeasiblytoimplies
is not
while
implies that he is mobile.
denied:mobile,
directly
orArgd
indirectly.
Literature on Concession

Indirect Contrast:
Although [John does not have a car]Argc,
[he has a bike]Argd.
Logical accounts of Concession
Previous logical accounts of Concession mirror the
distinction between Direct and Indirect Contrast.
Direct Contrast:
(p ∧ q) ∧ (p →¬q)
Indirect Contrast:
(p ∧ q) ∧ ∃r[(p →¬r) ∧ (q → r)]
Previous accounts of Concession
Previous approaches to Concession mainly focus on
how the expectation is denied (either directly or
indirectly).
They are almost silent about how the expectation is
created, i.e. on the relation between Argc and the
expectation that must be presupposed.
Some [Lagerwerf, 98], [Sanders et al., 92] generally
state it is of a causal nature.
We think that characterizing how the relation is created
is crucial for defining the semantic of concessive
relations. We tried to take a first step starting from an
empirical analysis of PDTB data.
Four subcases of Concession
Toy examples:
Causality: Although [John studied hard]argc, [he did not
pass the exam]argd.
Implication: [Penguins are birds]argc. Nevertheless [they
do not fly]argd
Correlation: [John will write the report]argc but [he'll finish
it at home]argd
Implicature: Although [John ate a lot of pizza]argc [he did
not eat it all]argd.
From the PDTB:
Causality: Although [they represent only 2% of the
population]argc, [they control nearly one-third of
discretionary income]argd.
Implication: [The prime minister]argd [whose hair is
thinning and gray and whose face has a perpetual
pallor]argc nonetheless [continues to display an energy, a
precision of thought and a willingness to say publicly what
most other Asian leaders dare say only privately]argd.
Correlation: [The Treasury will raise 10 billion in fresh
cash by selling 30 billion of securities...]argc. But [rather
than sell new 30-year bonds, the Treasury will issue 10
billion of 29-year, nine-month bonds]argd.
Implicature: Although [it is not the first company to
produce the thinner drives]argc, [it is the first with an 80megabyte drive]argd.
Empirical (double) annotation
on 1000 PDTB tokens
Inter-annotator agreement  k = 0.8
The analysis provides some evidence that the source of
expectation is not always a causal relation.
Implication
Necessary conditions, rather than causal effects,
inherited from some kind of prototype.
Although [working for USA intelligence]argc, [Mr. Noriega
was hardly helping the U.S. exclusively]argd.
Although [insider trading has long been criminal]argc, [for
example it has never been statutorily defined]argd.
[You can do all this]argc even if [you’re not a reporter or a
researcher or a scholar or a member of Congress]argd.
Correlation
Divergence from a contextually relevant trend
Although [the notes held at a price of 92 to 93 immediately
after the reset]argc, [they started falling soon afterward]argd.
[The LDP won by a landslide in the last election, in July
1986]argc. But [less than two years later, the LDP started to
crumble, and dissent rose to unprecedented heights]argd.
[Yet the rowing machine hasn't been touched since]argd
even though [he has moved it across the country with him
twice]argc
Correlation
Events that “surprisingly” occur together
Although [started in 1965]argc [Wedtech didn’t really get
rolling until1975]argd.
[The favorite remains Fernando Collor de Mello, a 40year-old former governor of the state of Alagoas]argc. But
[…Mr. Collor has slipped to about 30% in the polls from a
high of about 43% only a few weeks ago]argd.
[The Journal listed the creation of the money fund as one
of the 10 most significant events in the world of finance in
the 20th century]argc. But [the Reserve Fund, America’s
first money fund, was not named, nor were the creators of
the money-fund concept, Harry Brown and myself]argd.
Implicature
Violation of a Gricean Maxim: Argc is insufficient or
unrelevant with respect to the speaker’s intentions.
Although [John ate a lot of pizza]argc [he did not
eat it all]argd.
[Open the computer case]argc but [do not touch
the wires]argd.
Although [it is not the first company to
produce the thinner drives]argc, [it is the first
with an 80-megabyte drive]argd.
Thank you!