усвоение импликатур детьми

Н. Зевахина (НИУ ВШЭ)

В. Долгоруков (НИУ ВШЭ)

ОТиПЛ, 06.12.2012

Усвоение импликатур детьми

Previous workSmith 1980 (some, all)Braine and Rumain 1981 (or, and)Paris 1973 (or, and)

When children are more logical than adults:experimental investigations of scalar implicature (Noveck 2001)

Modals (might, must; does not have to, cannot)a puppet who utters an exhaustive series of modal

statements.Consider three boxes. One is open and has a toy

parrot and a toy bear in it (the Parrot + Bear Box), the second is open and has only a parrot (the Parrot-only Box), and the third stays covered (Box C).

Critical statementThere might be a parrot in the box.On the one hand, if the participant adopts an

explicit, logical interpretation of Might (where Might is compatible with Has to), one would expect an affirmative reply (‘The puppet is right’). On the other hand, if the participant adopts a pragmatic, restrictive interpretation for Might (where Might is not compatible with Has to) one would expect a negative reply (‘The puppet is wrong’).

Participants32 5-year-olds, 20 7-year-olds, 16 9-year-olds

and 20 adult native English speakers participated in the study (Introductory Psychology course).

Results

ResultsSeven-year-olds' rate of logical interpretations with

respect to There might be a parrot in the box (80%) is intriguing not only because they respond at rates that are significantly above chance levels but because they do so at a rate that is significantly higher than that of the adults (35%). Most adults assume that the possibility that the parrot will be found in the hidden box is wrong because the expectation is that the parrot's presence in the hidden box is necessary. Nine-year-olds look less like the 7-year-olds; 69% provide the logically correct answer. Nevertheless, the difference between 9-year-olds and adults is significant.

ResultsSeven-year-olds tend to accept the logical

interpretation of There might be a parrot in the box whereas adults tend to draw out its pragmatic potential.

Logical interpretations of Might remain the default and that they give way to pragmatic interpretations.

Experiment 2: Favoring logical interpretations

Experiment 2 aims to verify the main findings of Experiment 1.More intensive training.A more thorough understanding of the task would encourage

logical interpretations.After successful completion of the training, participants were

presented the same scenario as in Experiment 1 and, this time, with two groups of modal terms.

Predictions: If the conclusions reported after Experiment 1 are confirmed, one should find that 5-year-olds appear less competent than the 7-year olds, that 7-year-olds demonstrate adult-like sophistication, but that adults still reveal evidence of producing an implicature while the 7-year-olds do not.

Participants19 5-year-olds, 16 7-year-olds as well as 16 adult

native English speakers participated in the study.

TrainingThe training task was carried out in a manner identical to that in Experiment 1.

That is, one exposed box had a horse alone and another had a horse and a fish. After the training was completed, the experimenter put the puppet down and said `Now, I would like to ask you a few questions about the covered box'. These are listed and numbered below:

Could the box be empty? (Answer: no)Could there be a cat in the box? (no)Could there be a fish by itself in the box? (no)Could there be a horse by itself in the box? (yes)Could there be a horse and a fish in the box? (yes)If we open the box, could there be a horse inside? (yes)If we open the box, could there be a fish inside? (yes)

If participants erred on any one question, the error was pointed out at the end of the round and the entire set was re-administered. Participants had three opportunities to answer all the questions in a round. Otherwise, their responses were not included in the analyses (which occurred among three 5-year-olds).

MaterialsTwo sets of statements were presented. Each set was presented by one of two puppets. E.g., might and might not (a modal expression that was not included in Experiment 1) were included in one set and has to and does not have to were included in the other. One set evaluated children's comprehension with the following modal expressions:There has to be a (Necessity)There does not have to be a (Non-necessity)There could be a (Possibility)There could not be a (Impossibility)

The other set evaluates the parrot and the bear's presence with:There must be a (Necessity)There might not be a (Non-necessity)There might be a (Possibility)There must not be a (Impossibility)

Results

ResultsThe extra attention paid to the training task

increased rates of logical responding.The intensive querying reduced the difference

between the 7-year-olds and adults with respect to the statement There might be a parrot in the box. The extra training appears to have encouraged logical responses among adults and at a rate that is significantly greater than that in Experiment 1.

Experiment 3Replication of Smith (1980), except for the language

and elimination of questions.Experiment in French.Some X [verb] Y or All X [verb] Y.Some elephants have trunks.Some birds live in cages.Given that the pragmatic interpretation of Some (Not

all) is proposed to arrive subsequent to the logical interpretation, the infelicitous Some sentences are predicted to yield more negative (‘No, I disagree’) responses as participants become older.

Participants31 8-year-olds, 30 10-year-olds, and 15 adult

native French speakers.

Materialsfive absurd All sentences (e.g. All chairs tell time).five true All sentences (e.g. All elephants have trunks).five false All sentences (e.g. All dogs have spots).five absurd Some sentences (e.g. Some stores are made

of bubbles).five true (and felicitous) Some sentences (e.g. Some

birds live in cages).five true (but pragmatically infelicitous) Some sentences

(e.g. Some giraffes have long necks).Participants had to either agree or disagree with these

statements.

Results

Scalar implicatures: experiments at the semantics-pragmatics interface(Papafragou and Musolino 2003)

For adults, we aim at verifying that scalar implicatures are produced regularly and in the contexts described by pragmatic theory.

For children, we aim at verifying that they are capable of producing scalar implicatures and under what conditions.

Experiment 130 Greek-speaking 5-year-olds and a group of 30 adults.Interpretation of three kinds of scalar terms: meriki

(‘some’), dio (‘two’) and arxizo (‘start’).Merika apo ta aloga pidiksan pano apo to fraxti.some of the horses jumped over of the fenceDio apo ta aloga pidiksan pano apo to fraxti.two of the horses jumped over of the fenceTo koritsi arxise na ftiaxni to pazl.the girl started to make the puzzleSubjects (5-year-olds and adults) were randomly assigned

to one of three conditions, determined by scale type.FillersDifferent procedures for adults and children

Truth Value Judgement Task

Usually 2 experimenters.The first one acts out short stories in front of the

subjects using small toys and props. The second one plays the role of a puppet (in this case Minnie) who watches the stories alongside the subjects. At the end of the story, the puppet is asked to say what she thinks happened in the story.

Instead of asking subjects if the puppet is ‘right’ or ‘wrong’, we asked whether the puppet ‘answered well’. This modification was made since we were interested in felicity, not truth.

Results

Adults’ and children’s justifications

Experiment 2Basic design of Experiment 1: subjects are asked

to judge statements containing the scalar terms some, two and start in situations which satisfy the truth conditions of stronger terms on the respective scales (i.e. all, three and finish).

However, 3 important modifications were made in order to test the hypothesis that children’s apparent inability to derive scalar implicatures may be due to the nature of the task and in particular children’s inability to infer the goals of the experimenter.

ModificationsTraining.Context in which the main character’s

performance becomes the focal point of the story.The puppet is asked to directly comment on the

main character’s performance.Participants: 32 Greek-speaking children.

Training

The child would then be asked whether ‘Minnie answered well’ and whether ‘we can say it better’.

The stories in Experiment 2 were all based on scenarios in which the main character was involved in a contest or a challenge. The main character’s performance therefore became the focal point of the stories and at the end, the puppet was asked to comment on how well the character in question had done, ‘How did X do?’ .

ResultsExperiment 1: children rejected the puppet’s

statements 12.5% of the time in the <all, some> condition, 10% of the time in the <finish, start> condition and 65% of the time in the <three, two> condition.

Experiment 2: 52.5% of the time for the <all, some> scale, 47.5% of the time for <finish, start> and 90% of the time for <three, two>.

Justifications

Results

Why children and adults sometimes(but not always) compute implicatures(Chierchia et al 2005)

The goal is to carefully examine the specific conditions that allow the computation of implicatures by children. In so doing, we demonstrate that children as young as 7 are able to compute implicatures in experimental conditions that properly satisfy certain contextual prerequisites for deriving such implicatures.

Experiment 1Partial replication of the experiment conducted by

Noveck (2001).18 7-year-olds and 19adult native speakers of Italian.15 sentences with some and 15 with all, based on

three types of information: factually universal, factually existential, and absurd.

Materialsfive absurd some sentences (e.g., Some stories are

made of bubbles).five true (and felicitous) some sentences (e.g., Some

children are blond).five true (but pragmatically under-informative) some

sentences (e.g., Some giraffes have long necks).five absurd all sentences (e.g., All doors sing).five true all sentences (e.g., All birds have wings).five false all sentences (e.g., All birds live in cages).

ProcedureThe task was a statement evaluation task.Listening.Agree or disagree with each statement or not?Explanations.

Results

DiscussionTwo possible explanations for these findings: children

could lack the ability to draw implicatures (Pragmatic Delay hypothesis) or they could have this ability, but are prevented from displaying their pragmatic competence by some feature of the experimental design (Pragmatic Limitation hypothesis).

The instructions were unconstrained (no direct evidence available).

Children did not understand the experimental instructions.

Experiment 2Manipulation of experimental demandsTraining phase before the test.Similar to Papafragou and Musolino (2003).21 Italian children.The same materials and design as Exp. 1.

ProcedureTraining session (presentation of 4 figures depicting a grape, a

cook, a cake, and a chair).The experimenter introduced the figures to the child by saying

that they were given by a friend who asked for the child’s help.For each figure the friend had indicated two ways of describing it

and wanted to know from the child which way was better (grape vs. fruit, cook vs. man, cake vs. sweet stuff, chair vs. piece of furniture).

Children who erred on 2 out of 4 trials would not be invited to continue with the testing phase of the experiment.

Then it was said to the child that she was going to listen to a series of statements and would be asked to say whether she agreed or not. She was also told that if she did not agree, she would occasionally be invited to explain why.

Results In the training session, all children had no hesitation in choosing

the most restrictive term to describe the relevant object.Therefore, all children continued with the experiment.The main result of the test phase of the experiment is that children

who participated in the training session rejected statements like Some giraffes have long necks to a much greater extent than did children who were not trained: the rejection rate was 12% for children without training, and it rose to 52% with training.

To establish whether training significantly affects performance, children’s correct responses from Experiment 1 were compared with the rate of logically correct responses in the present experiment.

Training had a strong effect on some children, but no effect whatsoever on other children.

Training enhances the rejection of under-informative statements in 7-yearolds.

2 questionsThe persistence of the effect of training on children’s

performance.

Do children that have been trained maintain the same level of performance when they are retested a period of time after the first test, without a new training session prior to the retest? We turn to this question in Experiment 3.

The optimal level of performance by children overall. Although some children clearly benefited from training, others did not. Earlier we pointed to another factor that could have deflated children’s performance, the absence of context. It is conceivable that all 7-year-olds will benefit from the use of context, regardless of training. This possibility will be examined in Experiment 4, using the Truth Value Judgment Task.

Experiment 3Retesting the same children who participated in

Experiment 2 one week after the first test, without repeating the preliminary training session.

Subjects were the same.The content of model sentences were changed.Procedure was the same.

ResultsChildren who rejected the critical some

statements after training (Experiment 2) failed to do so when retested without additional training. The rate of rejection dropped from 52% in Experiment 2 to 22% in the present experiment.

However, there was a group of children who rejected under-informative sentences.

Impasse?

Experiment 415 Italian-speaking children and 12 Italian-

speaking undergraduate students.Subjects were asked to judge 5 statements

including some which were true, but under-informative in the context of use (e.g., Some monkeys are eating a biscuit in a situation in which all monkeys were eating a biscuit).

Fillers: clearly true and clearly false.

ProcedureVideo-taped version of the Truth Value

Judgement Task.Children watched a video featuring an

experimenter acting out stories using props and toys and holding a puppet, Carolina, who was watching the stories alongside the child. At the end of each story, Carolina said what had happened in the story. The child was instructed to say whether Carolina’s statement was a good or a bad description of what happened, and to explain her answer whenever she judged Carolina to have ‘said the wrong thing.’

ResultsChildren rejected the critical statements nearly as

often as adults: the rejection rate was 75% for children and 83% for adults.