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A LITTLE STORY
Mary went to a birthday party at Jane's house. Jane's
mother gave Mary a balloon. While Mary was walking home, it popped.
Mary cried.
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Sentence -- NounPhrase VerbPhrase
Sentence -- AdverbialConjunction
Sentence Sentence
NounPhrase -- ProperName
NounPhrase -- Pronoun
NounPhrase -- Determiner Noun
NounPhrase -- Possessive Noun
NounPhrase -- NounPhrase PrepositionalPhrase
Noun -- Noun Noun
Possessive -- NounPhrase 's
PrepositionalPhrase -- Preposition NounPhrase
VerbPhrase -- IntransitiveVerb
VerbPhrase -- BitransitiveVerb
NounPhrase NounPhrase
VerbPhrase -- VerbPhrase PrepositionalPhrase
VerbPhrase -- VerbPhrase Adverb
A Dictionary:
a: Determiner
at: Preposition
birthday: Noun
balloon: Noun
cry: IntransitiveVerb
give: BitransitiveVerb
go: IntransitiveVerb
home: Adverb, Noun
house: Noun
it: Pronoun
Jane: ProperName
Mary: ProperName
mother: Noun
party: Noun
pop: IntransitiveVerb
to: Preposition
walk: IntransitiveVerb
while: AdverbialConjunction
Note: the dictionary must give
the root form for verbs of different tenses, e.g.,
RootForm (went) = go
RootForm (gave) = give
RootForm (popped) = pop
RootForm (cried) = cry
Also, we need verb sequence rules which will tell us, for example, that
was walking is a past tense
progressive verb with RootForm(MainVerb) = walk
SYNTAX: DERIVATION TREES
Sentence
/ \
/ VerbPhrase
/ / \
/ / PrepositionalPhrase
/ / / \
/ / / NounPhrase
/ / / / \
/ / / / PrepositionalPhrase
/ / / / / \
/ / / NounPhrase / NounPhrase
/ / / / \ / / \
NounPhrase | / / Noun / Possessive\
| | / / / \ | / | \
| VerbPhrase / / / \ | NounPhrase| \
| | | / / \ | | | \
Proper IntranVerb Prep Art Noun Noun Prep Proper 's Noun
Mary went to a birthday party at Jane's house
Sentence
/ \____
/ \
NounPhrase VerbPhrase
/ \ / \ \____________
/ \ / \ \
Possessive \ / NounPhrase NounPhrase
| \ / | / \
Proper 's Noun BitransitiveVerb Proper Art Noun
Jane's mother gave Mary a balloon
Sentence
----------------------------/ / \
| ---------/ \_______
| Sentence \
| / \ \
| ---/ VerbPhrase Sentence
| | / \ / \
| NounPhrase VerbPhrase \ NounPhrase VerbPhrase
| | | \ | |
AdConj Proper IntransVerb Adverb Pronoun IntransVerb
While Mary was walking home, it popped.
Sentence
/ \
NounPhrase VerbPhrase
| |
Proper IntransVerb
Mary cried.
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SYNTAX: ANNOTATED DERIVATION TREES
Sentence
/ \
/ VerbPhrase
/ / \
/ / PrepositionalPhrase
| | [to-modifier]
/ / / \
/ / / NounPhrase
/ / / / \
/ / / / PrepositionalPhrase
/ / / / / \
/ / / NounPhrase / NounPhrase
/ / / / \ / / \
NounPhrase | / / Noun / Possessive \
[subject] | | | | | / \ |
| | / / / \ | / \ |
| VerbPhrase / / / \ | NounPhrase| |
| | | / / \ | | | |
Proper IntranVerb Prep Art Noun Noun Prep Proper 's Noun
Mary went to a birthday party at Jane's house
Sentence
/ \____
/ \
NounPhrase VerbPhrase
[subject] / \ \
/ \ / \ \_____________
/ \ / \ \
Possessive \ / NounPhrase NounPhrase
| | | [indirect obj] [direct obj]
| \ / | / \
Proper 's Noun BitransitiveVerb Proper Art Noun
Jane's mother gave Mary a balloon
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A problem for parsing: syntactic ambiguity!
Example 1:
Time flies like an arrow.
Example 2:
John drove the car through the village.
John drove the car with the racing stripes.
John drove the car in the driveway.
SEMANTICS: MEANING REPRESENTATION
Conceptual Dependency Meaning Representation
(Roger Schank and Robert Abelson, Scripts, Plans, Goals and
Understanding, New York: Wiley, 1977, pp. 43-44)
Basic Axiom: For any two
sentences that are identical in meaning, regardless of language,
there should be only one representation.
Ex.: Mary gave Tom a book; Tom was given a book by Mary
Tom is a bachelor; Tom is an unmarried man; Tom,
who is unmarried, is a man.
Corollary: Any information
in a sentence that is implicit must be made explicit in the representation
of the meaning of that sentence.
Ex.: Someone gave Tom a book; Tom was given a
book.
PRIMITIVE ACTS OF CD REPRESENTATION
ATRANS: the transfer of an abstract relationship
such as possession, ownership or control
examples: give, sell
PTRANS: the transfer of the physical location
of an object
examples: put, go
PROPEL (an object)
MOVE (one's body part)
GRASP (an object)
INGEST (an object)
EXPEL (an object)
MTRANS: the transfer of mental information between
animals or within an animal
examples: think, tell
MBUILD: the construction by an animal of new
information from old information
example: form an idea
SPEAK
ATTEND (pay attention to)
In addition, we have STATES and CHANGES OF STATE for
sentences like John is happy, John lost weight.
Mary went to a birthday party at Jane's house.
Ptrans
Agent Mary
Object Mary
From ?Somewhere
To BirthdayParty
Loc-at House
Possessed-by Jane
Tense Past
SEMANTICS: ANAPHORIC REFERENCE
RESOLUTION
Sample rule: To find the antecedent of an anaphor, choose the
most recently referred-to object of the correct sort (correct
sort for 'it' is inanimate)
Examples: John saw a car. It was red.
The car belonged to John. It was red.
John saw a car. He was happy.
The car belonged to John. He was happy.
Mary went to a birthday party at Jane's house. Jane's mother
gave Mary a balloon. While Mary was walking home, it popped.
It : refers to event or inanimate object or animal
Previous references to events or inanimate objects:
birthday party
Jane's house
balloon
Mary's house ("home")
If we choose the most recently referred-to event or inanimate
object, we have Mary's house popping!
Therefore, we need to know that balloons are the sorts of things
that pop; houses aren't!
SUPPLEMENTARY WAYS TO REPRESENT SEMANTIC
INFORMATION
Semantic Networks
Thing
____________/\____________
| |
Object Event
___________/ \____________ . . . .
| |
Animate Inanimate
_____/ \_____ _____/ \______
| . . . | | . . . . |
Human Animal Building Toy
/ \ / \ / \ / \
Woman Man Dog Cat House Skyscraper Doll Balloon
Frames
House
Isa Building
Function Dwelling
Structure WoodFrame | Brick | Stucco
Balloon
Isa Toy
Structure Rubber filled with air
Toy
Isa Object
Function Amuse children
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PRAGMATICS: BEYOND SENTENCE MEANING TO DISCOURSE
RULES AND WORLD KNOWLEDGE
SCRIPTS
(Roger Schank and Robert Abelson, Scripts, Plans, Goals and Understanding, New York: Wiley, 1977, pp. 43-44)
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A COFFEE SHOP STORY (by Merrie Bergmann):
John went to a coffee shop. He ordered eggs and bacon. He gave the waitress a big tip and he left.
Question: Did the waitress bring John eggs and bacon?
Did John pay for the eggs and bacon?
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Restaurant Script (track: coffee shop)
Props: Tables Menu Food(F) Check Money
Roles: Customer(S) Waiter(W) Cook(C) Cashier(M) Owner(O)
Entry Conditions: S is hungry. S has money.
Results: S has less money. O has more money. S is not hungry.
S is pleased (optional)
Scene 1: Entering
S PTRANS S into restaurant
S ATTEND eyes to tables
S MBUILD where to sit
S PTRANS S to table
S MOVE S to sitting position
Scene 2: Ordering
(menu on table) (W brings menu)
S PTRANS menu to S W PTRANS W to table
| W ATRANS menu to S
| |
---------------------------
|
S MTRANS food list to CP(S)
*S MBUILD choice of F
S MTRANS signal to W
W PTRANS W to table
S MTRANS 'I want F' to W
W PTRANS W to C
W MTRANS (ATRANS F) to C
|
---------------------------
| |
C MTRANS 'no F' to W C DO (prepare F script)
W PTRANS W to S to Scene 3
W MTRANS 'no F' to S
(to back to *) or (go to Scene 4 at no pay path)
Scene 3: Eating
C ATRANS F to W
W ATRANS F to S
S INGEST F
(Optionally return to Scene 2 to order more) or (go to Scene 4)
Scene 4: Exiting
S MTRANS to W (W ATRANS check to S)
W MOVE (write check)
W PTRANS W to S
W ATRANS check to S
S ATRANS tip to W
S PTRANS S to M
S ATRANS money to M
S PTRANS S to out of restaurant (no pay path starts here)
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MORE PRAGMATICS: What else is needed to
understand this story?
1. Assuming that we have a birthday party script, one of the EXIT conditions might be: People at a birthday party are (still) happy when they leave. 2. Common knowledge about crying: People who cry are unhappy or surprised or afraid. 3. So we have a puzzle: why did Mary cry? Some rules of orderly discourse: 1. Narratives usually proceed in an orderly fashion, for example, sentence order indicates temporal order. Between the birthday party and Mary's crying, two things happened: Mary was walking home, and the balloon popped. 2. Important facts are usually stated. Because the birthday party doesn't explain Mary's crying, one of these two events most likely does explain her crying. 3. Which one of these two events is the culprit? Two possible (complementary) strategies for deciding: a. Pragmatics of sentence structure While X, Y. The focus of this sentence is Y. That's the important thing. So infer: the balloon's popping made Mary cry, because it is the important event that happened. b. World knowledge: What sort of events make children unhappy? Walking home? Not as a rule! Balloons popping? Sure: the loud noise, the fact that the balloon is now "broken", . . .