Conversational Implicature &
Relevance Theory
Outline
? Introduction
? Pragmatics
? Principles underlying the implicature phenomenon
? Types of implicature
? Examples
Introduction
? Pragmatics
? Implicature = anything that is inferred from an
utterance but that is not a condition for the truth
of the utterance,(Gazdar,1979)
? Presupposition = anything that is presupposed
to be true given an utterance
Presupposition
? Possible criterion,given an utterance U,the
proposition p that is inferred by listener from both
U and not U is a presupposition
? Example:
? The king of France is bold.
? The king of France is not bold.
From both sentences,the affirmation and the
negation,we infer that there is a king of France
Implicature
? Implicatures are inferred based on the assumption
that the speaker observes or flouts some principles
of cooperation (different authors have identified
different principles)
? Grice – 4 principles (so called,maxims”)
? Levinson (1981),Horn (1984) – 2 principles
Grice Principles
? Quantity maxim
? the communication must be adequately but not
overly informative
? Quality maxim
? the speaker does not believe it to be false and
has adequate evidence for his statement
? Maxim of relation or relevance
? the communication must be relevant
? Maxim of manner
? the communication must be clear,unambiguous,
brief,and orderly
Grice Principles,reduced form
? The Q-principle
? Say as much as you can (given I)
? The I-principle
? Say no more than you must (given Q)
Types of Implicatures
? Standard implicature – based on the assumption
that the speaker observes the cooperation
principles
? A,I’ve just run out of petrol.
? B,There is a garage just around the corner.
B infers that he can find oil at the garage.
Types of Implicatures
? Flouting implicatures – based on the assumption
that the speaker deliberately flouts one of the
communication principles
? A,The capital of Morocco is Casablanca
? B,Yes,and the capital of U.K,is Moskow
A infers that his statement was wrong.
Types of Implicatures,another classification
? Generalized implicatures – inferred without a
special reference to context:
? John walked into a house yesterday.
? Infer that the house was not John’s house
? Particularized implicatures – inferred only due to a
special context
? A,Can you tell me the time?
? B,Well,the milkman is here.
It must be the time when the milkman comes.
Properties of Implicatures
? Strong dependency on context (see the complex
implicature example)
? Defeasibility (they are not entailments,and
addition of new facts can cancel them)
Why is the problem of implicature hard?
? Deals with the,logic defying” aspects of
communication
? The cooperation principles are hard to formulate
(work is still done in this area,and no author
claims he has a final form of the principles)
? Implicatures are,hidden”,i.e,they do not appear
in text,which makes a statistical approach less
accessible
Conversational Implicature
? Lexical (and logical) scales:
? all,most,many,some
? numbers
? subset,set
? According to the cooperation principles,the
speaker must use the right member of the scale
Conversational Implicature,Examples
? Bill has got some of Chomsky’s papers
? Infer that Bill does not have all the Chomsky’s
papers
? There will be five of us for dinner tonight
? Infer that there will not be more than five of us
for dinner tonight
? A,I like Mary,She is intelligent and good hearted.
B,Yes,she is intelligent.
? Infer that B thinks Mary is not good-hearted
Complex conversational Implicatures
? Scenario,Kai’s parents promise him rewards for
things he does not like to do,a small reward for
washing his hair,a medium reward for eating
broccoli and peas,and a high reward for cleaning
up his room.
? Kai’s mother says:
? Kai had broccoli and peas.
? We infer that Kai did not clean up his room
conversational Implicatures
? Based on the Q-principle
? The speaker must not make a weaker claim (i.e.,
he must say as much as he can,as long as this
does not increase the effort)
? It takes the same amount of effort to say:
? John walked into his house yesterday.
? John walked into a house yesterday.
Other Types of Scales
? Ranked entities:
? A,Is Jill a professor yet?
? B,She’s a senior lecturer.
Infer that Jill is not a professor.
? Whole/part relation
? A,Did you manage to read that chapter I gave
you?
? B,I read the first couple of pages.
Infer that B didn’t read the whole chapter.
Other Types of Scales
? Instance-of
? A,Do you have any juice?
? B,I have grape,orange and tomato.
Infer that B does not have any apple,lemon..
? Alternate values (not necessarily ordered)
? A,Did you get Paul Newman's autograph?
? B,I got Joanne Woodward's.
B didn’t get Newman’s autograph
Quantity principle,refined
? Welker (1994) shows that the quantity principle,
as formulated by Grice,is too strong:
? A,I'm having a dinner party and I need four
more chairs.
? B,John has two chairs.
Implicature,B has at most two chairs
? A,I'm having a dinner party and I need four
more chairs.
? B,John has four chairs.
This time,no implicature
Quantity principle,refined
? Communication must be "..,as informative as is
required (for the current purposes of the
exchange)"
? Idea,even the conversational implicatures depend
on context – not only the surrounding text,but
also the situation
False Predictions
? Not all scales generate implicatures all the time
? The relevance principle may cancel some
conversational implicatures:
? A,What did you buy for your mother?
? B,I bought her flowers.
? Assuming that roses are on top of the flowers
scale,this leads to the implicature,I didn’t buy
her roses”.
False Predictions,continued
? The implicature is not inferred because the
statement is relevant enough
? However,a possible implicature in this example is
“I didn’t buy her a present”,The difference is that
while it is not relevant which kind of flowers he
bought,it is relevant whether he bought a present
or not
Matsumoto’s constraint
? Let <S,W> be a scale (with S stronger than W)
? Then a conversational implicature is inferred if the
following condition is met:
? the choice of W instead of S must not be
attributable to the observance of the maxims of
quantity-2,relation or obscurity avoidance
(manner-1).
Matsumoto’s constraint,contd
? Equivalently,observing the quantity-2,non-
obscurity and relevance takes precedence over
observing quantity-1
? Idea,the relevance maxim seems to hold the key
to the process of inferring implicatures
,Affirmative” Implicatures
? So far,the conversational implicatures seem to
simply negate the stronger claim when the weaker
is presented
? We can also have implicatures that do not involve
negation:
? If you finish your thesis by September you'll be
eligible for the job.
? Implicature,You'll be eligible for the job if and
only if you finish your thesis by September.
Pragmatic Schemes
? Let S and W be members of a scale,with S
stronger than W
? Q-based implicature:
? S entails W
? "W" implicates "not S"
? R-based implicature:
? S entails W
? "W" implicates "S"
Pragmatic Schemes,applied
? [P and Q] entails [P or Q]
? "[P or Q]" Q-implicates "[not [P and Q]]"
? Thus the implicature is not P or not Q,or,only
one of P and Q can hold”
? [P iff Q] entails [if P,Q]
? "[if P,Q]" R-implicates "[P iff Q]"
?,If you finish your thesis by September you
will be eligible for the job” – as seen above,the
implicature is that the condition is necessary
Informativeness
? In both previous examples,the implicatures enrich
the informational contents of the message
? Observation,What is conveyed always implies
logically what is said
? Conclusion,the implicature mechanism allows the
quantity of information in a message to grow
Richardson&Richardson critique
? I broke a finger.
? implicates,I broke one of my own fingers.
? I found a finger.
? implicates,I found someone else's finger.
? Which of the schemes can be applied?
? Q-implicatures or R-implicatures?
? Again,relevance is the key
Cardinal numbers
? Problem,A and B go to a party,They make a bet,
A says that there will be 20 people at the party
when they arrive,When they get to the party,there
are 25 people,Who wins the bet?
Cardinal numbers,ambiguity
? The source of ambiguity is the use of numbers; the
sentence,there will be 20 people” can be used to
express:
? There will be at most 20 people there.
? There will be exactly 20 people there.
? There will be at least 20 people there.
? The context of the bet supports the second
interpretation
Cardinal numbers,continued
? In Britain you have to be 18 to drive a car.
? The new houses are big enough for families with
three children.
? A default reasoning (world knowledge is essential)
decides the interpretation (“at most” –,at least”)
Conclusions
? The Q principle and R(I) principle give rise to the
same result,a strengthening of the meaning of the
utterance
? The relevance principle plays a key role,which
constrains the Q and R principles
? Cardinal numbers are a special case of scale; they
allow punctual interpretation,but also interval
interpretation
Relevance Theory
Outline
? Introduction
? Pragmatics
? Principles underlying the implicature phenomenon
? Types of implicature
? Examples
Introduction
? Pragmatics
? Implicature = anything that is inferred from an
utterance but that is not a condition for the truth
of the utterance,(Gazdar,1979)
? Presupposition = anything that is presupposed
to be true given an utterance
Presupposition
? Possible criterion,given an utterance U,the
proposition p that is inferred by listener from both
U and not U is a presupposition
? Example:
? The king of France is bold.
? The king of France is not bold.
From both sentences,the affirmation and the
negation,we infer that there is a king of France
Implicature
? Implicatures are inferred based on the assumption
that the speaker observes or flouts some principles
of cooperation (different authors have identified
different principles)
? Grice – 4 principles (so called,maxims”)
? Levinson (1981),Horn (1984) – 2 principles
Grice Principles
? Quantity maxim
? the communication must be adequately but not
overly informative
? Quality maxim
? the speaker does not believe it to be false and
has adequate evidence for his statement
? Maxim of relation or relevance
? the communication must be relevant
? Maxim of manner
? the communication must be clear,unambiguous,
brief,and orderly
Grice Principles,reduced form
? The Q-principle
? Say as much as you can (given I)
? The I-principle
? Say no more than you must (given Q)
Types of Implicatures
? Standard implicature – based on the assumption
that the speaker observes the cooperation
principles
? A,I’ve just run out of petrol.
? B,There is a garage just around the corner.
B infers that he can find oil at the garage.
Types of Implicatures
? Flouting implicatures – based on the assumption
that the speaker deliberately flouts one of the
communication principles
? A,The capital of Morocco is Casablanca
? B,Yes,and the capital of U.K,is Moskow
A infers that his statement was wrong.
Types of Implicatures,another classification
? Generalized implicatures – inferred without a
special reference to context:
? John walked into a house yesterday.
? Infer that the house was not John’s house
? Particularized implicatures – inferred only due to a
special context
? A,Can you tell me the time?
? B,Well,the milkman is here.
It must be the time when the milkman comes.
Properties of Implicatures
? Strong dependency on context (see the complex
implicature example)
? Defeasibility (they are not entailments,and
addition of new facts can cancel them)
Why is the problem of implicature hard?
? Deals with the,logic defying” aspects of
communication
? The cooperation principles are hard to formulate
(work is still done in this area,and no author
claims he has a final form of the principles)
? Implicatures are,hidden”,i.e,they do not appear
in text,which makes a statistical approach less
accessible
Conversational Implicature
? Lexical (and logical) scales:
? all,most,many,some
? numbers
? subset,set
? According to the cooperation principles,the
speaker must use the right member of the scale
Conversational Implicature,Examples
? Bill has got some of Chomsky’s papers
? Infer that Bill does not have all the Chomsky’s
papers
? There will be five of us for dinner tonight
? Infer that there will not be more than five of us
for dinner tonight
? A,I like Mary,She is intelligent and good hearted.
B,Yes,she is intelligent.
? Infer that B thinks Mary is not good-hearted
Complex conversational Implicatures
? Scenario,Kai’s parents promise him rewards for
things he does not like to do,a small reward for
washing his hair,a medium reward for eating
broccoli and peas,and a high reward for cleaning
up his room.
? Kai’s mother says:
? Kai had broccoli and peas.
? We infer that Kai did not clean up his room
conversational Implicatures
? Based on the Q-principle
? The speaker must not make a weaker claim (i.e.,
he must say as much as he can,as long as this
does not increase the effort)
? It takes the same amount of effort to say:
? John walked into his house yesterday.
? John walked into a house yesterday.
Other Types of Scales
? Ranked entities:
? A,Is Jill a professor yet?
? B,She’s a senior lecturer.
Infer that Jill is not a professor.
? Whole/part relation
? A,Did you manage to read that chapter I gave
you?
? B,I read the first couple of pages.
Infer that B didn’t read the whole chapter.
Other Types of Scales
? Instance-of
? A,Do you have any juice?
? B,I have grape,orange and tomato.
Infer that B does not have any apple,lemon..
? Alternate values (not necessarily ordered)
? A,Did you get Paul Newman's autograph?
? B,I got Joanne Woodward's.
B didn’t get Newman’s autograph
Quantity principle,refined
? Welker (1994) shows that the quantity principle,
as formulated by Grice,is too strong:
? A,I'm having a dinner party and I need four
more chairs.
? B,John has two chairs.
Implicature,B has at most two chairs
? A,I'm having a dinner party and I need four
more chairs.
? B,John has four chairs.
This time,no implicature
Quantity principle,refined
? Communication must be "..,as informative as is
required (for the current purposes of the
exchange)"
? Idea,even the conversational implicatures depend
on context – not only the surrounding text,but
also the situation
False Predictions
? Not all scales generate implicatures all the time
? The relevance principle may cancel some
conversational implicatures:
? A,What did you buy for your mother?
? B,I bought her flowers.
? Assuming that roses are on top of the flowers
scale,this leads to the implicature,I didn’t buy
her roses”.
False Predictions,continued
? The implicature is not inferred because the
statement is relevant enough
? However,a possible implicature in this example is
“I didn’t buy her a present”,The difference is that
while it is not relevant which kind of flowers he
bought,it is relevant whether he bought a present
or not
Matsumoto’s constraint
? Let <S,W> be a scale (with S stronger than W)
? Then a conversational implicature is inferred if the
following condition is met:
? the choice of W instead of S must not be
attributable to the observance of the maxims of
quantity-2,relation or obscurity avoidance
(manner-1).
Matsumoto’s constraint,contd
? Equivalently,observing the quantity-2,non-
obscurity and relevance takes precedence over
observing quantity-1
? Idea,the relevance maxim seems to hold the key
to the process of inferring implicatures
,Affirmative” Implicatures
? So far,the conversational implicatures seem to
simply negate the stronger claim when the weaker
is presented
? We can also have implicatures that do not involve
negation:
? If you finish your thesis by September you'll be
eligible for the job.
? Implicature,You'll be eligible for the job if and
only if you finish your thesis by September.
Pragmatic Schemes
? Let S and W be members of a scale,with S
stronger than W
? Q-based implicature:
? S entails W
? "W" implicates "not S"
? R-based implicature:
? S entails W
? "W" implicates "S"
Pragmatic Schemes,applied
? [P and Q] entails [P or Q]
? "[P or Q]" Q-implicates "[not [P and Q]]"
? Thus the implicature is not P or not Q,or,only
one of P and Q can hold”
? [P iff Q] entails [if P,Q]
? "[if P,Q]" R-implicates "[P iff Q]"
?,If you finish your thesis by September you
will be eligible for the job” – as seen above,the
implicature is that the condition is necessary
Informativeness
? In both previous examples,the implicatures enrich
the informational contents of the message
? Observation,What is conveyed always implies
logically what is said
? Conclusion,the implicature mechanism allows the
quantity of information in a message to grow
Richardson&Richardson critique
? I broke a finger.
? implicates,I broke one of my own fingers.
? I found a finger.
? implicates,I found someone else's finger.
? Which of the schemes can be applied?
? Q-implicatures or R-implicatures?
? Again,relevance is the key
Cardinal numbers
? Problem,A and B go to a party,They make a bet,
A says that there will be 20 people at the party
when they arrive,When they get to the party,there
are 25 people,Who wins the bet?
Cardinal numbers,ambiguity
? The source of ambiguity is the use of numbers; the
sentence,there will be 20 people” can be used to
express:
? There will be at most 20 people there.
? There will be exactly 20 people there.
? There will be at least 20 people there.
? The context of the bet supports the second
interpretation
Cardinal numbers,continued
? In Britain you have to be 18 to drive a car.
? The new houses are big enough for families with
three children.
? A default reasoning (world knowledge is essential)
decides the interpretation (“at most” –,at least”)
Conclusions
? The Q principle and R(I) principle give rise to the
same result,a strengthening of the meaning of the
utterance
? The relevance principle plays a key role,which
constrains the Q and R principles
? Cardinal numbers are a special case of scale; they
allow punctual interpretation,but also interval
interpretation
