A Short Introduction to Psycholinguistics:

Garden-Path Sentence

Department of Computer Science,

Graduate School of Information Science and Technology,

The University of Tokyo

T. SUWA

Basic Concepts – Syntax and Parsing

A big elephant squashed a small fly easily.

Basic Concepts – Syntax and Parsing

A big elephant squashed a small fly easily. A N V A N Adv

NP NP

VP

S

Syntax tree: structure of sentence

D D

Basic Concepts – Syntax and Parsing

A big elephant squashed a small fly easily. A N V A N Adv

Lexical category: classification for grammatical roles of words

D D

Basic Concepts – Syntax and Parsing

A big elephant squashed a small fly easily. A N V A N Adv

NP NP

VP

S “Sentence”

D D

Basic Concepts – Syntax and Parsing

A big elephant squashed a small fly easily. D A N V A N Adv

NP NP

VP

S “Noun Phrase” (for Subject)

“Verb Phrase”

D

Basic Concepts – Syntax and Parsing

A big elephant squashed a small fly easily. D A N V D A N Adv

NP NP

VP

S

“Determiner”

“Adjective” “Noun”

Basic Concepts – Syntax and Parsing

A big elephant squashed a small fly easily. A N V A N Adv

NP NP

VP

D D

S

“Verb”

“Noun Phrase” (for Object) “Adverb”

Basic Concepts – Syntax and Parsing

Parsing = making syntax tree from sentence

A big elephant squashed a small fly easily. A N V A N Adv

NP NP

VP

S

D D

A big elephant squashed a small fly easily.

Parse

What is a garden-path sentence?

What is a garden-path sentence?

What is a garden-path sentence?

What is a garden-path sentence?

Example

I put the candy in the box into the bag.

I put the candy in the box into the bag.

Example

I put the candy in the box into the bag.

Example

NP V

VP

S

I put the candy in the box into the bag.

Example

N NP D V

NP

VP

S

NP

I put the candy in the box into the bag.

Example

N NP D V

NP

VP

S

N D

PP

P

NP

I put the candy in the box into the bag.

Example

N NP D V

NP

VP

S

N D

PP

P

Require correction

I put the candy in the box into the bag.

NP

Example

N NP D V

NP

VP

S

N D

PP

P

NP

Require correction

NP

I put the candy in the box into the bag.

Example

N NP D V

NP

VP

S

N D

PP

P

NP

NP

N D

PP

P

NP

I put the candy in the box into the bag.

Example

N NP D V

NP

VP

S

N D

PP

P

NP

NP

N D

PP

P

Garden-path arising suggests we prefer as first choice

I put the candy in the box …

What the Example Indicates

I put the candy in the box into the bag.

here

I put the candy in the box …

rather than

Syntactic Ambiguity

Syntactic Ambiguity = Situation that there is more than one syntax tree for the same sentence

They discuss the violence on TV.

They discuss the violence on TV.

Syntactic Ambiguity

Time flies like an arrow.

Time flies like an arrow.

Time flies like an arrow.

NP V PP

VP S

NP V NP

VP S

V NP PP

VP

Fundamental Issue

1. How do humans prefer one interpretation to others for the same sentence?

Fundamental Issue

2. When encountering a garden-path, how do humans correct temporary syntax tree?

Fundamental Issue

2. When encountering a garden-path, how humans correct temporary syntax tree?

Even today, there’s no good

general explanation

“Follow the next direction ASAP.”

Experiment for Detecting Garden-Path

“Put the candy in the box into the bag.”

Experiment for Detecting Garden-Path

“Put the candy in the box …”

Result of Experiment

“Put the candy in the box into the bag.”

Result of Experiment

Conclusion

Garden-path sentences are

• Interesting phenomena in itself

• Suggestive of how humans recognize sentences

• Still not well-understood

• Have close relation to humans’ preference of interpretation