Informativeness, Relevance and Scalar Implicature: Informativeness, Relevance and Scalar Implicature Author: Roybn Carston
Presenter: Ovidiu Fortu Outline: Outline Introduction
Principles underlying the implicature phenomenon
Types of implicatures
Examples Introduction: 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: Presupposition Possible criterion: given an utterance U, the proposition p that is inferred by listener from both U and not U is a presupposition
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: 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: Grice Principles Quantity maxim
the communication must be adequately but not overly informative
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: Grice Principles, reduced form
Say as much as you can (given I)
Say no more than you must (given Q)
Types of Implicatures: 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: 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: 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: 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?: 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 Scalar Implicature: Scalar Implicature Lexical (and logical) scales:
all, most, many, some
According to the cooperation principles, the speaker must use the right member of the scale Scalar Implicature, Examples: Scalar 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 Scalar Implicatures: Complex Scalar 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 Scalar Implicatures: Scalar 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: 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.
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: 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: 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: Quantity principle, refined
Communication must be "... as informative as is required (for the current purposes of the exchange)"
Idea: even the scalar implicatures depend on context – not only the surrounding text, but also the situation False Predictions: False Predictions Not all scales generate implicatures all the time
The relevance principle may cancel some scalar 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: 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: Matsumoto’s constraint Let <S, W> be a scale (with S stronger than W)
Then a scalar 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: 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: “Affirmative” Implicatures So far, the scalar 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: Pragmatic Schemes Let S and W be members of a scale, with S stronger than W
S entails W
"W" implicates "not S"
S entails W
"W" implicates "S" Pragmatic Schemes, applied: 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: 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: 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: 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: 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: 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: 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 Scalar implicatures: experiments at the semantics–pragmatics interface: Scalar implicatures: experiments at the semantics–pragmatics interface Authors:
Anna Papafragoua, Julien Musolinob
Presenter: Ovidiu Fortu Paper contents: Paper contents A study of how scalar implicatures are inferred by humans
Two sets of experiments are performed with a group of young children to test their ability to infer implicatures
Only scalar implicatures are considered for the tests First Set of Tests: First Set of Tests Subjects:30 5-year-old children and 30 adults, all native speakers of Greek (all experiments in Greek)
Three scales :
oli, meriki (all, some)
tris, dio (three, two)
teliono, arxizo (finish,start)
Experiment setup: Experiment setup Subjects are presented a situation that allows a stronger claim
Subjects (both adults and children) answer questions about the situation
Questions admit yes/no answers (the subjects must assess the truth value of a claim in the given context Results : Results While adults have no problem of inferring implicatures, children seem to be less sensitive to weak clauses
Only 10% - 12.5% of the weak claims in case of scale (all, some)
However, for other scales, children have better results – 65% in case (three, two), which shows that different scales are perceived differently Justifications for Answers: Justifications for Answers Subjects were also required to provide a brief justification for their answers
Adults overwhelmingly justified their answers by stating the stronger claim
Children gave two types of justifications:
Repeating of the given statement
The stronger statement
Even in cases when they gave the right answer, the children had wrong justifications (rougly 70% of the justifications for the scale <all, some> were of the first type) Experiment 2: Experiment 2 Subjects: a set of 30 children (distinct from the first set)
Children were trained to recognize pragmatic anomaly
The stories that described the situations were modified to focus on the performance of the principal character Experiment 2, Results: Experiment 2, Results Children could reject the weak statements reliably better:
52% <all, some> (previously 12%)
47.5% <finish, start> (previously 10%)
90% <three, two> (previously 65%) When children are more logical than adults: experimental investigations of scalar implicature: When children are more logical than adults: experimental investigations of scalar implicature Author:
Ira A. Noveck
Presenter: Ovidiu Fortu Objectives: Objectives Study the scalar implicatures experimentally
Establish that scalar implicatures are psychologically real and common in reasoning scenarios
Establish how this class of weak scalar terms develops
Three sets of experiments: Three sets of experiments Experiment 1 – modal “might” (when it is comparable with “must”)
Experiment 2 – a follow up of experiment 1; designed to determine the extent to which the scalar implicature can be suspended
Experiment 3 – investigates weak claims based on the “some” quantifier Experiment 1: Experiment 1 Subjects: 32 5-year olds, 20 7 year olds, 16 9 year olds, 20 adults (all native English speakers)
Set-up: two open boxes, one with a parrot and one with a parrot and a bear
A puppet then states 8 claims:
(1) There has to be a parrot in the box (true);
(2) There does not have to be a parrot in the box (false);
(3) There might be a parrot in the box (true);
(4) There cannot be a parrot in the box (false);
(5) There has to be a bear in the box (false);
(6) There might be a bear in the box (true);
(7) There does not have to be a bear in the box (true);
(8) There cannot be a bear in the box (false)
Experiment 1, Results: Experiment 1, Results Is the statement of the puppet true?
Necessary conclusion (parrot)
Has to be a parrot Yes 75% 90% 88% 100%
Does not have to be a parrot No 72% 75% 75% 100%
Might be a parrot Yes 72% 80% 69 35
Cannot be a parrot No 66 80% 100% 100%
Total 73% 81% 83% 83%
Possible conclusion (bear)
Has to be a bear No 47 65 88% 100%
Does not have to be a bear Yes 66 75% 81% 100%
Might be a bear Yes 53 80% 100% 100%
Cannot be a bear No 53 80% 100% 100%
Total 55 75% 92% 100% Experiment 3: Experiment 3 The results and setup were very similar to the ones in previous paper
The tests with older subjects showed better results – more than 85% for 7-year olds; 10 year olds had performance comparable to adults
Children have more problems with this scale (in one test only 6% rejected all weak claims) Conclusions: Conclusions Ability to communicate using pragmatics is developed later in the growth
Implicatures are difficult to infer, requiring more experience