Lecture 19 Word Meanings II

1. Lecture 19Word Meanings II CSCE 771 Natural Language Processing • Topics • Description Logic III • Overview of Meaning • Readings: • Text Chapter 189NLTK book Chapter 10 March 27, 2013

2. Overview • Last Time (Programming) • Wordnet overview • Today • Computational Semantics • Feature based grammars • Readings: • Text 19 • NLTK Book: Chapters 9 and 10 • Next Time: Computational Lexical Semantics

3. HW review • Dropboxes • Soon to exist: • NER for handbook

4. 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

5. 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) • Adjectives • related nouns • similar to • participle of verb • Adverbs • root adjectives http://en.wikipedia.org/wiki/WordNet

6. http://wordnet.princeton.edu/ • x

7. WordnetonlineFig 19-1

8. 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

9. Fig 19-2 Noun relations in wordnet

10. Fig 19-3 Verb relations in wordnet

11. Fig19-4-like IS-A (hyponym) Chain for lemma bass#7

12. Sister terms (= coordinate terms)

13. 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

14. Fig 19.5 Common Thematic Roles

15. 19.6 Examples of Thematic Roles

16. 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.

17. Case Frames for verbs • Break • Agent: Subject, Theme:Object • Agent: Subject, Theme:Object, Instrument: PP-with • Instrument:Subject, Theme:Object • Theme: Subject

18. 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.

19. Prop Bank • PropBank is a corpus that is annotated with verbal propositions and their arguments—a "proposition bank". • http://verbs.colorado.edu/~mpalmer/projects/ace.html http://en.wikipedia.org/wiki/PropBank

20. PropBank Online • http://verbs.colorado.edu/~mpalmer/projects/ace.html

21. FrameNet

22. Framenet Core Roles

23. 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]

24. FrameNet Index of Lexical Units

25. Selectional restrictions of rolesfrom PropBank

26. Fig 19-7 Hamburger Edible?

29. Figure 19.8 Shank’s Conceptual Dependencies • Roger Schank 1969  Professor at Yale aclweb.org/anthology-new/C/C69/C69-0201.pdf

30. 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

31. Conceptual syntax rules • Ref: ??? • Elaine Rich’s • Text on AI www.csc.csudh.edu/jhan/Fall2006/csc411/Notes/Chapter%207.ppt

32. 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

33. CD for “John at the egg.” • . www.csc.csudh.edu/jhan/Fall2006/csc411/Notes/Chapter%207.ppt

34. 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

35. 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

36. Modifiers