1. INTRODUCTION TO ARTIFICIAL INTELLIGENCE
Massimo Poesio LAB 9: WORDNET

2. COMMONSENSE KNOWLEDGE SOURCES FOR AI / NLP
There are now several sources of commonsense knowledge that we can use to study its role in reasoning / develop systems able to use commonsense knowledge
The best known is WordNet, a lexical database based on semantic networks developed by George Miller and his collaborators in Princeton

3. A LEXICAL RESOURCE BUILT ON SEMANTIC NETWORK PRINCIPLES
WordNet is a LEXICAL DATABASE created at Princeton
Freely available for research from the Princeton site
It contains information about a variety of SEMANTICAL RELATIONS
Three sub-databases (supported by psychological research as early as (Fillenbaum and Jones, 1965))
NOUNs
VERBS
ADJECTIVES and ADVERBS
Each database organized around SYNSETS
2004/05
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4. The noun database About 90,000 forms, 116,000 senses Relations:
hypernym
breakfast -> meal
hyponym
meal -> lunch
has-member
faculty -> professor
member-of
copilot -> crew
has-Part
table -> leg
part-of
course -> meal
antonym
leader -> follower
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5. USING WN ONLINE http://wordnetweb.princeton.edu/perl/webwn
Example: CELL PHONE

6. EXERCISE 1
Find the entry for ROBOT

7. LEXICAL RELATIONS IN WORDNET
Wordnet contains information about lexical relations between MEANINGS (more on meanings below)
The type of lexical relations depends on the type of lexical entry

8. LEXICAL RELATIONS FOR NOUNS
ISA (hypernymy)
PART-OF (meronymy)

9. TAXONOMIC INFORMATION IN WORDNET
WordNet is a very rich source of taxonomic information
This information can be found by following HYPERNYMY links

10. Hypernyms
2 senses of robin                                                        Sense 1 robin, redbreast, robin redbreast, Old World robin, Erithacus rubecola -- (small Old World songbird with a reddish breast)        => thrush -- (songbirds characteristically having brownish upper plumage with a spotted breast)            => oscine, oscine bird -- (passerine bird having specialized vocal apparatus)                => passerine, passeriform bird -- (perching birds mostly small and living near the ground with feet having 4 toes arranged to allow for gripping the perch; most are songbirds; hatchlings are helpless)                    => bird -- (warm-blooded egg laying vertebrates characterized by feathers and forelimbs modified as wings)                        => vertebrate, craniate -- (animals having a bony or cartilaginous skeleton with a segmented spinal column and a large brain enclosed in a skull or cranium)                            => chordate -- (any animal of the phylum Chordata having a notochord or spinal column)                                => animal, animate being, beast, brute, creature, fauna -- (a living organism characterized by voluntary movement)                                    => organism, being -- (a living thing that has (or can develop) the ability to act or function independently)                                        => living thing, animate thing -- (a living (or once living) entity)                                            => object, physical object --                                                 => entity, physical thing --
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11. EXERCISE 2
Find the hypernyms of ROBOT

12. UPPER ONTOLOGY IN WORDNET
The noun hierarchy is divided in distinct hierarchies, each with its top element

13. • {act,action,activity}
• {animal,fauna}
• {artifact}
• {attribute,property}
• {body,corpus}
• {cognition,knowledge}
• {communication}
• {event,happening}
• {feeling,emotion}
• {food}
• {group,collection}
• {location,place}
• {motive}
• {natural object}
• {natural phenomenon}
• {person,human being}
• {plant,flora}
• {possession}
• {process}
• {quantity,amount}
• {relation}
• {shape}
• {state,condition}
• {substance}
• {time}

14. MERONYMY IN WORDNET WordNet contains information about PARTS
Stored as information about MERONYMS
Example: TREE

15. EXERCISE 3 Find the parts of house Find the parts of building
Find the parts of car

16. Meronymy wn beak –holon Holonyms of noun beak 1 of 3 senses of beak
beak, bill, neb, nib
PART OF: bird
2004/05
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17. EXERCISE 4
Find the entry of bank

18. THE ORGANIZATION OF THE LEXICON
“eat”
“eats”
EAT-LEX-1
eat0600
eat0700
“ate”
“eaten”
WORD-FORMS
LEXEMES
SENSES
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19. The organization of the lexicon
stock0100
STOCK-LEX-1
stock0200
STOCK-LEX-2
stock0600
“stock”
stock0700
STOCK-LEX-3
stock0900
stock1000
WORD-STRINGS
LEXEMES
SENSES
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20. Synonymy cheap0100 “cheap” …. …… cheapXXXX inexp0900 “inexpensive”
CHEAP-LEX-1
“cheap” ….
CHEAP-LEX-2 ……
cheapXXXX
INEXP-LEX-3
inexp0900
“inexpensive”
inexpYYYY
WORD-STRINGS
LEXEMES
SENSES
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21. Synsets
Senses (or `lexicalized concepts’) are represented in WordNet by the set of words that can be used in AT LEAST ONE CONTEXT to express that sense / lexicalized concept: the SYNSET
E.g.,
{chump, fish, fool, gull, mark, patsy, fall guy, sucker, shlemiel, soft touch, mug} (gloss: person who is gullible and easy to take advantage of)
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22. EXERCISE 5
Find the senses of hand, palm, slick, and stock.

23. EXERCISE 6
Find the hypernyms of LAW

24. The verb database About 10,000 forms, 20,000 senses
Relations between verb meanings:
Hypernym
fly-> travel
Troponym
Walk -> stroll
Entails
Snore -> sleep
Antonym
Increase -> decrease
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25. Relations between verbal meanings
V1 ENTAILS V2 when Someone V1 (logically) entails Someone V2 - e.g., snore entails sleep
TROPONYMY when To do V1 is To do V2 in some manner - e.g., limp is a troponym of walk
2004/05
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26. EXERCISE 7
Find the antonyms of accelerate

27. The adjective and adverb database
About 20,000 adjective forms, 30,000 senses
4,000 adverbs, 5600 senses
Relations:
Antonym (adjective)
Heavy <-> light
Antonym (adverb)
Quickly <-> slowly
2004/05
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28. EXERCISE 8
Find the antonyms of dangerous

29. How to use Can also use online Command line:
Getting WordNet:
Can also use online
Command line:
Get synonyms:
wn –synsn bank
Get hypernyms:
wn –hypen robin
(also for adjectives and verbs): get antonyms
wn –antsa right
2004/05
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30. WORDNET FOR OTHER LANGUAGES
MultiWordNet (multiwordnet.fbk.eu)
A Multilingual WordNet
Italian WordNet
Synsets aligned with English WordNet (1.6) whenever possibile
Compatible versions developed for Hebrew, Portuguese, Romanian and Spanish

31. WORDNET AND DOLCE
The LOA group has been

32. OTHER SOURCES OF COMMONSENSE KNOWLEDGE
OpenCyc:
ConceptNet
Discussed next week
DBPedia:

33. READINGS
C. Fellbaum, WordNet. MIT press