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Human simulations of vocabulary learning. Gillette, Gleitman, Gleitman, Lederer. Présentation Interface Syntaxe-Psycholinguistique Y-Lan BOUREAU. Outline. Some background The problem to be solved Facts : nouns’ acquisition precedes verbs’ acquisition Existing theory - PowerPoint PPT Presentation
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Human simulations of vocabulary learning
Présentation Interface Syntaxe-PsycholinguistiqueY-Lan BOUREAU
Gillette, Gleitman, Gleitman, Lederer
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OutlineSome background
The problem to be solvedFacts : nouns’ acquisition precedes verbs’ acquisitionExisting theoryGillette et al.’s hypothesis
Simulation experimentLearning from observationLearning from linguistic hints
Discussion
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The problem of language learning
Children learn language from scratchTraditional hypothesis :
Children hear adults speakThey spot that « cat » is uttered most frequently when there is a cat aroundThey infer that « cat » means ‘cat’
But babies’ vocabulary does not reflect input frequencies
much more nouns than verbs in babies vocabulary
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Nouns are learnt earlierA conceptual hypothesis :
Verbs are conceptually more difficultSo cannot be learnt until babies display adequate conceptual knowledge
Alternative hypothesis : information requirements
Verbs require some syntax to be already acquired (e.g. : I know that Mommy is coming)
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Pairing word to worldThree sources of information :
Nonlinguistic evidence (e.g. Mommy says « cat » when the cat is there)Linguistic evidence :• Co-occurrence of semantically related words in
sentences (e.g. food names usually appear with verbs like « eat »)
• Syntactic structures in which words occur (e.g. a verb with one subject and two complements is likely to be of the « give » kind)
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HypothesisHypothesis : the baby
(1) acquires a small stock of nouns by word-to-world pairing (2) uses that stock of nouns as a scaffold for constructing representations of the linguistic input that will support a more efficient learning procedure
Support : correlation of changes in vocabulary size with appearance of multiword speech
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A simulation experimentPrinciple :
Adult learners • (no conceptual issues any more)
Trying to guess : most frequently used nouns or verbs
Observational clues : video clipsLinguistic clues : co-occurring words, syntactic frame
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First experimentOnly videoclipsAdults trying to guess 24 nouns and 24 verbs
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Results, Part I : Nouns win
Nouns are guessed with much better results than verbs :
MEAN % CORRECT FINAL IDENTIFICATIONexp 1
0
10
20
30
40
50
NOUNS VERBS
MEAN %CORRECT FINALIDENTIFICATION
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Imageability rulesProvided clues are exclusively visualNouns of the set (e.g. elephant, plane, bag) are a lot more « imageable » than verbs (e.g. think, know, wait)
IMAGEABILITY
012345678
NOUNS VERBS
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Results, part II
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101520253035404550
MEA
N %
CO
RR
ECT
FIN
ALID
EN
TIF
ICAT
ION
CO
RR
EC
TIN
GW
ITH
IMAG
EAB
ILIT
Y
Nouns
Verbs
Verbs
Nouns
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Conclusion of experiment I
The one relevant factor seems to be imageability
Not that surprising : from a video, you learn imageable things ; a thing that is not imageable would be hard to picture !!
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Linguistic clues vs. Observational clues
All nouns removed. 6 conditions :
1 : videoclips (but with a bip for the verb)2 : alphabetical lists of nouns3 : 1+2 (videoclips + alphabetical lists)4 : syntactic frames with all nonsense words5 : sentences with only the verb as nonsense6 : 1+5 (videoclips + sentences)
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Linguistic clues vs. Observational clues
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Linguistic clues vs. Observational clues
6 conditions :1 : videoclips (but with a bip for the verb)2 : alphabetical lists of nouns3 : 1+2 (videoclips + alphabetical lists)4 : syntactic frames with all nonsense words5 : sentences with only the verb as nonsense6 : 1+5 (videoclips + sentences)
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ResultsMean % correct identification
0102030405060708090
100
video
clips
lists
of no
uns
video
clips
+ lis
tssy
ntacti
c fram
esse
ntenc
es+n
ouns
video
s+se
ntenc
es
Mean % correctidentification
No nouns provided !!
No more visual information !!
Nouns reintroduced
Visuals reintroduced
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Linguistic clues vs. Observational clues
Remarkably : leap between 3 and 4, whereas the reverse could have been expected !Interestingly, those verbs that were best learnt in the observational learnings show a decrease between 3 and 4
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DiscussionVerbs : complementary distributions (12 never learnt with visual clues = 12 best learnt with linguistic clues) This distribution corresponds to the « imageability » criterion :
Quite logically, you can learn visually only what is visually representableVerbs that use higher level linguistic representations have to wait until those can be constructed
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Discussion : general scheme
First, imageable words are learnt on a word-to-world pairing basis
Those imageable words are mostly nounsThat would explain why nouns make up most of young infants’ vocabulary
Second, this first set of words allows learning of new words on a sentence-to-world pairing
Thus conceptual words can be learnt as well
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Some reservationsThe argument structure is the same across languages (logical requirements), but :
Adults already know the words, so they could try to guess the verbs by exhaustive search with all the information given (e.g. : the best performance is for « look », and it is probably due to the use of « look » with « at » )
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The End