How Children Learn the Meanings of Nouns and Verbs

Tingting “Rachel” ChungPh. D. Candidate in

Developmental PsychologyUniversity of Pittsburgh

What’s in a word?

beef/bif/Noun (mass)Cow/ox meat

RootPhonologyGrammatical categoryMeaningMorphology

Why is word learning interesting?

Inductive problem - Potentially wide range of hypotheses

Mapping problem – Cross-linguistic variations

High growth rate

Why is word learning interesting?

Inductive problem - Potentially wide range of hypotheses

Mapping problem – Cross-linguistic variations

High growth rate

What’s a Gavagai?

Why is word learning interesting?

Inductive problem - Potentially wide range of hypotheses

Mapping problem – Cross-linguistic variations

High growth rate

Language may organize concepts in different ways

Melissa Bowerman Differences between English and Korean

English-speaking adults

Korean-speaking adults

English-learning 2-year-olds

Korean-learning 2-year-olds

Why is word learning interesting?

Inductive problem - Potentially wide range of hypotheses

Mapping problem – Cross-linguistic variations

High growth rate

Statistics

10,000 words by 1st grade5.5 per day from 1.5 to 6 yrs

40,000 words by 5th grade20.5 per day from 1st to 5th grade

Sources of information about word meaning

Principles and constraints Pragmatics Syntax

Principles and Constraints

The Whole Object Assumption

The Taxonomic Assumption

Mutual Exclusivity

Principles and Constraints

The Whole Object Assumption

The Taxonomic Assumption

Mutual Exclusivity

Whole Object Assumptionin Initial Mappings

Evidence

Tendency of whole object interpretation• in ambiguous situations• with inappropriate syntax• in languages without count/mass distinction

More nouns in early vocabulary

Novel nouns learned faster

Whole Object Assumption

Criticisms

Only roughly 40% of early words are object labels.

Children learning Chinese, Japanese, and Korean learn verbs and nouns simultaneously

Whole Object Assumption

Explanations

Object concepts are richer and more cohesive

Ostensive teaching of nouns more prevalent in middle-class Americans

Whole Object Assumption

Consequences - speculations

Verbs are harder to learn

Adjectives are harder to learne.g., color words (Soja, 1994)

Principles and Constraints

The Whole Object Assumption

The Taxonomic Assumption

Mutual Exclusivity

Taxonomic Assumptionin Word Extensions

Evidence

Find another

one

Find another

dog

Taxonomic Assumptionin Word Extensions

Basic Level (Perceptually based)

Early categorization in infancy may be at superordinate level

But most early words and extensions are basic-level.

Taxonomic Assumptionin Word Extensions

Conceptual extensions

Taxonomic Assumptionin Word Extensions

Shape Bias Find another

dax

Principles and Constraints

The Whole Object Assumption

The Taxonomic Assumption

Mutual Exclusivity

Mutual Exclusivity

Evidence

Fast mapping of novel label to novel object when familiar object is present

Lack of fast mapping of second labels

Mutual Exclusivity

Value

Fast-mapping

Avoiding redundant hypotheses

Overcoming whole object assumption

Overriding taxonomic assumption

Nature of Principles and Constraints

Are they language specific? How and when do children overcome

them? Are they applicable to learning of words

in other classes?

Potential Principles and Constraints in Verb Learning

Whole Event Assumption?

Taxonomic Assumption?

Mutual Exclusivity?

Whole Event Assumption

Unlikely

Agentive manner/action outcome > instrument > agent

Event parsing/representation is crucial

Taxonomic Assumption

What is event taxonomy?

Basic-level verbs?

WordNet (Miller & Felbaum, 1991)

Mutual exclusivity

Fast-mapping of verbs in 3-year-olds

Effect size is smaller

Role of Syntax

General syntax-semantics links Tendency of object label interpretation with a noun and action interpretation with a verb (Brown 1957)

BUT: How does the child know the grammatical category of a word?

Syntax and verb meanings

Syntactic bootstrapping (Gleitman)

Syntax narrows down possible hypothesis about verb meaning

He is daxing

He is daxing it.

He is daxing to her.

He is daxing from her.

Naigles (1990)

Problems with syntactic bootstrapping research

Infinite hypothesis space reduced by 15 times is still infinite

Confound of semantics and syntax

Requires syntactic knowledge

Role of Social and Pragmatic Cues

Joint attention

Referential intent

Case of autism

Summary

Multiple sources of information are needed in word mapping.

Constraints are “default principles” that can be overridden given appropriate circumstances.

Research should move beyond nouns.

Discussion questions

Is there ordering of constraints?

How are event nouns learned?(e.g., party, bath, trip)

How are dual category words learned?

Do nouns have to be learned before verbs are?