Lecture 19 Word Meanings II

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# Lecture 19 Word Meanings II - PowerPoint PPT Presentation

Lecture 19 Word Meanings II. CSCE 771 Natural Language Processing. Topics Description Logic III Overview of Meaning Readings: Text Chapter 189NLTK book Chapter 10. March 27, 2013. Overview. Last Time (Programming) Wordnet overview Today Computational Semantics

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Lecture 19Word Meanings II

CSCE 771 Natural Language Processing

• Topics
• Description Logic III
• Overview of Meaning
• Text Chapter 189NLTK book Chapter 10

March 27, 2013

Overview
• Last Time (Programming)
• Wordnet overview
• Today
• Computational Semantics
• Feature based grammars
• Text 19
• NLTK Book: Chapters 9 and 10
• Next Time: Computational Lexical Semantics
HW review
• Dropboxes
• Soon to exist:
• NER for handbook
Wordnet
• Most synsets are connected to other synsets via a number of semantic relations. These relations vary based on the type of word, and include:
• Nouns
• hypernyms: Y is a hypernym of X if every X is a (kind of) Y (canine is a hypernym of dog) “superordinate” “superclass”
• hyponyms: Y is a hyponym of X if every Y is a (kind of) X (dog is a hyponym of canine) “IS-A”
• coordinate terms: Y is a coordinate term of X if X and Y share a hypernym (wolf is a coordinate term of dog, and dog is a coordinate term of wolf) “sibling”
• holonym: Y is a holonym of X if X is a part of Y (building is a holonym of window) “HAS-PART”
• meronym: Y is a meronym of X if Y is a part of X (window is a meronym of building) “IS-PART” “IS-MEMBER”

http://en.wikipedia.org/wiki/WordNet

Verbs

• hypernym: the verb Y is a hypernym of the verb X if the activity X is a (kind of) Y (to perceive is an hypernym of to listen)
• troponym: the verb Y is a troponym of the verb X if the activity Y is doing X in some manner (to lisp is a troponym of to talk)
• entailment: the verb Y is entailed by X if by doing X you must be doing Y (to sleep is entailed by to snore)
• coordinate terms: those verbs sharing a common hypernym (to lisp and to yell)
• related nouns
• similar to
• participle of verb

http://en.wikipedia.org/wiki/WordNet

Word senses
• A word sense is a distinct meaning
• Synonym sets are relations among word senses
• couch/sofa, car/automobile
• antonyms also
• long/short, big/large, rise/fall
• extremes; or opposite in direction
Thematic Roles
• 19.19 “Sasha broke the window.”
• exists e,x,y breaking(e) & breaker(e, Sasha) & brokenThing(e, y) & window(y)
• 19.20 Pat opened the door.
• Deep or thematic roles
• Panini (Indian grammarian) circa 7th-4th century BC
• Fillmore 1968, Gruber 1965
Variations of expression
• John broke the window.
• John broke the window with a rock.
• The rock broke the window.
• The window broke.
• The window was broken by John.
Case Frames for verbs
• Break
• Agent: Subject, Theme:Object
• Agent: Subject, Theme:Object, Instrument: PP-with
• Instrument:Subject, Theme:Object
• Theme: Subject
19.4.3 Problems with Thematic Roles
• Example 19.27
• the cook opened the jar with the new gadget.
• the new gadget opened the jar.
• Example 19.28
• Shelly ate the banana with a fork.
• *The fork ate the banana.
Prop Bank
• PropBank is a corpus that is annotated with verbal propositions and their arguments—a "proposition bank".

http://en.wikipedia.org/wiki/PropBank

PropBank Online
FrameNet Examples
• ... [Cook the boys] ... GRILL [Food their catches] [Heating_instrumenton an open fire].
• [Avenger I] 'll GET EVEN [Offender with you] [Injury for this]!
• [ Punishment This attack was conducted] [Support in] RETALIATION [ Injury for the U.S. bombing raid on Tripoli...
• [Sleeper They] [Copula were] ASLEEP [Duration for hours]
Figure 19.8 Shank’s Conceptual Dependencies
• Roger Schank 1969  Professor at Yale

aclweb.org/anthology-new/C/C69/C69-0201.pdf

Conceptual Dependency
• Governing Categories
• PP – an actor or object corresponds to concrete nominal nouns
• ACT – an action
• LOC – a location of a conceptualization
• T – time of a conceptualization
• Assisting Categories
• PA – attribute of a PP
• AA – attribute of an ACT
• Graphical representation

aclweb.org/anthology-new/C/C69/C69-0201.pdf

Conceptual syntax rules
• Ref: ???
• Elaine Rich’s
• Text on AI

www.csc.csudh.edu/jhan/Fall2006/csc411/Notes/Chapter%207.ppt

CD Examples
• John ran.
• John is tall.
• John is a doctor.
• A nice boy.
• John’s dog
• John pushed the cart
• John took the book from Mary
• John drank milk
• john fertilized the field
• the plants grew
• Bill shot Bob

www.csc.csudh.edu/jhan/Fall2006/csc411/Notes/Chapter%207.ppt

CD for “John at the egg.”
• .

www.csc.csudh.edu/jhan/Fall2006/csc411/Notes/Chapter%207.ppt

CD “John prevented Mary from giving the book to Bill.”
• .More tenses and modes
• p past
• f future
• t transition
• k continuing
• c conditional
• / negative
• ? Interrogative
• pil present

www.csc.csudh.edu/jhan/Fall2006/csc411/Notes/Chapter%207.ppt

RestaurantScript
• Roger Schank again
• Collection of scenes describing typical events
• e.g. “visit a restaurant”
• Entering
• Ordering
• Eating
• Paying/Leaving

www.csc.csudh.edu/jhan/Fall2006/csc411/Notes/Chapter%207.ppt