Treebanking for the grammar Acquisitionist my goldfish convinced - - PowerPoint PPT Presentation

Treebanking for the Acquisitionist

(or: some times I wished I had a treebank)

Jeffrey Lidz University of Maryland Department of Linguistics

The learning problem

A child exposed to sentences acquires a grammar

my goldfish convinced me that linguists drive more expensive cars than banjo players what did your goldfish convince you that linguists drive __ ? * who did your goldfish convince you that linguists drive more expensive cars than __ ?

What determines the nature of projection

• f a system from a corpus?

2

Constraints on projection

Rich, innate hypothesis space makes limited kinds of structures possible

Chomsky 1965, Fodor 1966, Pinker 1979, ...

Input Grammar Language Acquisition Device

3

What the LAD typically does

Input Grammar Language Acquisition Device Define space of possible grammars Accounts for how acquired grammar extends beyond experience

4

reconstruction effects

Leddon & Lidz 2005

Miss Cruella knows which picture of herself Janie put up herself = Janie/Miss Cruella Miss Cruella knows how proud of herself Janie was herself = Janie/*Miss Cruella 4-yr-olds know that reconstruction is optional for moved arguments but obligatory for moved predicates Despite fact that speech to children includes no examples

• f anaphors contained in wh-phrases

What the LAD typically does

Input Grammar Language Acquisition Device Define space of possible grammars Accounts for how acquired grammar extends beyond experience

6

Inside a learning mechanism

Input Encoding

• f

Experience Hypothesis Space (Statistical) Inference

7

Innate structure is designed to learn

Inside a learning mechanism

Input Encoding

• f

Experience Hypothesis Space (Statistical) Inference

8

Is structure of grammar reflected in input? What information is available for statistical inference?

Kannada syntax & acquisition

Kannada 40m speakers

9

Kannada Ditransitives

Is the structure of the grammar reflected in input to the learner? Is there any information in the input that learners could use to identify underlying structure?

10

Kannada Ditransitives

Hari Rashmi-ge pustaka-vannu kalis-id-a Hari Rashmi-dat book-acc send-pst-3sm Hari Rashmi-ge pustaka-vannu kalisi-koTT-a Hari Rashmi-dat book-acc send-BEN-3sm ‘Hari sent the book to Rashmi’

11

Kannada Ditransitives

Hari pustaka-vannu Rashmi-ge kalis-id-a Hari book-acc Rashmi-dat send-pst-3sm Hari pustaka-vannu Rashmi-ge kalisi-koTT-a Hari book-acc Rashmi-dat send-BEN-3sm ‘Hari sent the book to Rashmi’

12

Dimensions of variation

+Ben

• Ben

Theme - Goal YES YES Goal - Theme YES YES

13

Benefactive = DOC

Possession Hari bangaloor-ige pustakavannu kalisida Hari pustakavannu bangaloor-ige kalisida * Hari bangaloor-ige pustakavannu kalisikoTTa * Hari pustakavannu bangaloor-ige kalisikoTTa Hari sent(*BEN) the book to Bangalore cf Eng: *Hari sent Bangalore the book

14

Possession?

• Ben

+Ben Theme - Goal NO YES Goal - Theme NO YES

15

Prominence?

• Ben

+Ben Possession NO YES Prominence ?? ??

Structural correlates of ±Ben

16

Binding Asymmetries

When can goal bind into theme? Hari pratiyobba lekhanige avaLa lekhanavannu kalisida * Hari avaLa lekhanavannu pratiyobba lekhanige kalisida Hari sent every author her article

• Ben: only when goal precedes theme

17

Binding Asymmetries

When can goal bind into theme? Hari pratiyobba lekhanige avaLa lekhanavannu kalisikoTTa Hari avaLa lekhanavannu pratiyobba lekhanige kalisikoTTa Hari sent(BEN) every author her article

+Ben: always - word order is irrelevant

18

What about Kannada

• Ben

+Ben Possession No Yes Prominence ?? GOAL

Goal is syntactically prominent in +Ben

19

Binding Asymmetries

When can theme bind into goal? Hari adara lekhanige pratiyondu lekhanavannu kalisida Hari pratiyondu lekhanavannu adara lekhanige kalisida Hari sent every article to its author

• Ben: always - word order is irrelevant

20

Binding Asymmetries

When can theme bind into goal? Hari adara lekhanige pratiyondu lekhanavannu kalisikoTTa Hari pratiyondu lekhanavannu adara lekhanige kalisikoTTa Hari sent-BEN every article to its author

+Ben: only when theme precedes goal

21

Prominence in Kannada

• Ben

+Ben Possession No Yes Prominence Theme Goal

Theme is syntactically prominent in -Ben

22

Underlying Configurations

subj V Goal Theme subj V Theme Goal Possession Ditranstive English: DOC Kannada: +BEN Locative Ditransitive English: Prep Dative Kannada: -BEN

23

Two Questions

Are children aware of asymmetries in prominence? The test: Kannada-learning 4-yr-olds How do learners identify which NP is prominent in ±Ben?

24

Method

Truth Value Judgement Task (Crain & McKee 1985)

Act out story with props & toys Puppet watches story Puppet gives summary statement Child tells Puppet if he’s right or wrong

25

Bound True

The girl gave every boy his horse Meaning 1: TRUE every boy gets his own horse Meaning 2: FALSE every boy gets the alien’s horse

1 2 3 4 5 6

26

Bound True

girl every boy his horse return-(BEN) girl his horse every boy return-(BEN) Meaning 1: TRUE every boy gets his own horse Meaning 2: FALSE every boy gets the alien’s horse

1 2 3 4 5 6

27

Bound False

The girl gave every boy his horse Meaning 1: FALSE every boy gets his own horse Meaning 2: TRUE every boy gets the alien’s horse

1 2 3 4 5 6

28

Bound False

Meaning 1: FALSE every boy gets his own horse Meaning 2: TRUE every boy gets the alien’s horse

1 2 3 4 5 6

girl every boy his horse return-(BEN) girl his horse every boy return-(BEN)

29

Kannada Predictions

• Ben

+Ben Possession No Yes Prominence Theme Goal

30

Kannada Predictions

If 4-yr-olds understand the relation between morphological form and syntactic prominence, then +BEN: Goal can always bind into Theme

• BEN: Goal can only bind into Theme when Goal

comes first Bound True condition: “yes” except in

• Ben Theme-Goal

31

Kannada Predictions

If 4-yr-olds understand the relation between morphological form and syntactic prominence, then +BEN: Goal can always bind Theme

• BEN: Goal can only bind Theme when Goal

comes first Bound False condition: “no” except in

• Ben Theme-Goal

32

Results: Bound True

25 50 75 100 Theme-Goal Goal-Theme Ben Affix No Ben Affix

% judged true The girl gave every boy his horse

Viau&Lidz 2008 33

Results: Bound False

25 50 75 100 Theme-Goal Goal-Theme Ben Affix No Ben Affix

% judged true The girl gave every boy his horse

Viau&Lidz 2008 34

Questions

Is there evidence of binding possibilities in speech to children? I wish I had a Kannada treebank to answer this! If no evidence of binding possibilities, is there some

• ther information that could be used?

I wish I had a Kannada treebank to answer this too

35

Binding data is sparse Gigaword NYT parsed corpus of English 385M words, 15M sentences V [QP] [PP to [NP ...pro...]] = 129

phi-feature match = 0 V [QP] [NP ...pro...] = 87 phi-feature match = 0

English Analogy

36

Syntactic Configurations

subj V Goal Theme subj V Theme Goal Possession Ditranstive English: DOC Kannada: +BEN Locative Ditransitive English: Prep Dative Kannada: -BEN Learning consists in selecting the appropriate abstract representation on the basis of surface form

37

A sketch of learning

Inferences from surface form to abstract structure cued by statistical asymmetry animacy asymmetry in goal arguments Inanimate goal 12 times more likely to be used as PP-

• dative. (Bresnan & Nikitina 2003)

if p(Str1 | inanimate goal) > p(Str2 | inanimate goal), then Str1 = locative dative & Str 2 = possession dative

38

A sketch of learning

Skewed distribution of inanimate goals is a good cue to underlying structure This inference is licensed only if a) the representations are antecedently available b) learners expect structures to leave a detectable statistical signature on the input

39

Learners use statistics to select a grammatical system with properties not exhibited in the statistics themselves Abstract representations must leave a statistical signature in surface form of language in order to be acquired Learners use this statistical signature to identify grammatical, but only because they know what to look for

Theoretical Conclusion

40

The acquisitionist wants to know when children can rely on their input to learn specific generalizations vs. need to project beyond their input what information is available to drive inferences from surface form to abstract grammatical structure Treebanks can be highly informative for answering these questions

Practical Conclusion

41