WordNets

wordnets
Piek Vossen
VU University Amsterdam

What kind of resource is the
Princeton WordNet?
● http://wordnet.princeton.edu/
● Developed by George Miller and his team at
Princeton University, as the implementation of
a mental model of the lexicon
● Mostly used database in language technology
● Enormous impact in language technology
development
● Large
● Free and downloadable
● English

Wordnet Starting point
● Lexical database organized around concepts instead of lexical
forms:
– Separates lexical forms from concepts
– Defines concepts through a relational model of meaning and not an
encyclopedic view
● Concept is defined by the notion of a synset: a set of synonyms
● Synsets distinguish different word meanings:
– {board, plank}{board, committee}{board, get on}
● The ‘synset’ as a weak notion of synonymy:
● “two expressions are synonymous in a/some linguistic context C
if the substitution of one for the other in C does not alter the truth
value.” (Miller et al. 1993)

Wordnet:
a network of semantically related words
{conveyance;transport}
{vehicle}
{motor vehicle; automotive vehicle}
{car; auto; automobile; machine; motorcar}
{cruiser; squad car; patrol car;
police car; prowl car}
{car mirror}
{car door}
{bumper}
{cab; taxi; hack; taxicab}
{car window}
{armrest}
{doorlock}
{hinge;
flexible joint}

Wordnet:
a network of semantically related words
hypernym
H
Y
P
O
N
Y
M
Y
{conveyance;transport}
{vehicle}
{motor vehicle; automotive vehicle}
{car; auto; automobile; machine; motorcar}
{cruiser; squad car; patrol car;
police car; prowl car}
hyponym
holonym meronym
MERONYMY
{cab; taxi; hack; taxicab}
{car mirror}
{car door}
{bumper}
{car window}
{armrest}
{doorlock}
{hinge;
flexible joint}

Wordnet 3.0 statistics
POS Unique Synsets Total
Strings Word-Sense
Pairs
Noun 117,798 82,115 146,312
Verb 11,529 13,767 25,047
Adjective 21,479 18,156 30,002
Adverb 4,481 3,621 5,580
Totals 155,287 117,659 206,941
Synonymy: two words shared a concept:
board, committee
Homonymy: one word belongs to two unrelated concepts:
board, plank
Polysemy: one word has more than one related concept:
university (building & institute)

Semantics of Nouns in WordNet
25 unique beginners for nouns
{act, action, activity} {natural object} {food}
{animal, fauna} {natural phenomenon} {time}
{artifact} {plant, flora} {substance}
{attribute, property} {possession} {group, collection}
{body, corpus} {process} {location, place}
{cognition, knowledge} {quantity, amount} {motive}
{communication} {relation}
{event, happening} {shape}
{feeling, emotion} {state, condition}

uilding
church
abbey
artifact
Lexicalization patterns
bird
object
canary
common
canary
animal
dog
entity
organism
crocodile
tree
plant
fl ower
rose
top-layer
25 unique
beginners
Basic Level
Concepts
(Rosch)

uilding
church
abbey
artifact
Lexicalization patterns
bird
object
canary
common
canary
animal
dog
entity
organism
crocodile
tree
plant
fl ower
• balance of two rose principles:
top-layer
25 unique
beginners
Basic Level
Concepts
● predict most features
● apply to most subclasses
• where most concepts are created
• amalgamate most parts
• most abstract level to draw a pictures

inessential
souvenir
garbage
threat
building
church
abbey
artifact
Lexicalization patterns
bird
object
canary
common
canary
entity
animal
dog
organism
crocodile
tree
plant
top-layer
curiosity
....etc....
waste
25 unique
variable beginners
fl ower
rose
basic level
concepts

leg
beak
Meronymy
tail

Meronymy & pictures

Meronymy
part
body part
tail
dog tail
Anchored Relational Model
Hyponymy
animal
plague
pet
hunter
dog
threat
beast of burden
carnivore
some
dogs
group
group of animals
pack
pack of dogs
watchdog, sheepdog, herding dog, lapdog, working
dog
Newfoundland
dalmatian

Meronymy
Component
Anchored Relational Model
part, limb, organ,
beak, foot,
ear, nose, head, etc.
Hyponymy
Superordinate
Basic Level
Whole
Subordinate
LANGUAGE CUTS UP REALITY IN FUNNY WAYS!
He takes too many medicines./He takes to much medicine.
material, comestibles,
medicine, cutlery,
means of payment,
means, assets, property,
stimulant, earthenware,
etc..
Multiform

EuroWordNet Multilingual database
vehículo
1
auto tren
vehicle
1
car train
2
English Words
2
Spanish Words
veicolo
1
auto treno
2
Italian Words
dopravní prost edník
1
auto vlak
2
Czech Words
voertuig
1
auto trein
2
Dutch Words
véhicule
1
voiture train
2
French Words
Fahrzeug
Auto Zug
1
2
German Words
liiklusvahend
1
auto killavoor
2
Estonian Words

EuroWordNet Multilingual database
vehículo
1
auto tren
vehicle
1
car train
2
English Words
2
Spanish Words
veicolo
1
auto treno
2
Italian Words
3 3
Czech Words
Inter-Lingual
Index
dopravní prost edník
1
auto vlak
2
Car
…
Train
…
Vehicle
voertuig
1
auto trein
2
Dutch Words
véhicule
1
voiture train
2
French Words
Fahrzeug
Auto Zug
1
2
German Words
liiklusvahend
1
auto killavoor
2
Estonian Words

EuroWordNet Multilingual database
vehículo
1
auto tren
vehicle
1
car train
2
English Words
2
Spanish Words
veicolo
1
auto treno
2
Italian Words
Domains
Transport
Road Air Water
3 3
Czech Words
Inter-Lingual
Index
dopravní prost edník
1
auto vlak
2
Top-ontology
Object
Device
TransportDevice
Car
…
Train
…
Vehicle
voertuig
1
auto trein
2
Dutch Words
véhicule
1
voiture train
2
French Words
Fahrzeug
Auto Zug
1
2
German Words
liiklusvahend
1
auto killavoor
2
Estonian Words

EuroWordNet Multilingual database
vehículo
1
auto tren
vehicle
1
car train
2
English Words
2
Spanish Words
veicolo
1
auto treno
2
Italian Words
Domains
Transport
Road Air Water
3 3
Czech Words
Inter-Lingual
Index
dopravní prost edník
1
auto vlak
2
Top-ontology
Object
Device
TransportDevice
Car
…
Train
…
Vehicle
voertuig
1
auto trein
2
Dutch Words
véhicule
1
voiture train
2
French Words
Fahrzeug
Auto Zug
1
2
German Words
liiklusvahend
1
auto killavoor
2
Estonian Words

● Inter-Lingual-Index: unstructured fund of concepts to
provide an efficient mapping across the languages;
● Index-records are mainly based on English WordNet
synsets and consist of synonyms, glosses and source
references;
● Various types of complex equivalence relations are
distinguished;
● Equivalence relations from synsets to index records: not on a
word-to-word basis;
The Multilingual Design
● Indirect matching of synsets linked to the same index items;

Complex mappings across languages
EN-Net
toe
finger
head
NL-Net
hoofd
kop
{ toe : part of foot }
{ finger : part of hand }
{ dedo , dito :
finger or toe }
{ head : part of body }
{ hoofd : human head }
{ kop : animal head }
= normal equivalence
= eq _has_hyponym
= eq _has_hyperonym
IT-Net
dito
ES-Net
dedo

From EuroWordNet to Global WordNet
● Currently, wordnets exist for more than 70 languages,
including: Arabic, Bantu, Basque, Chinese, Bulgarian,
Estonian, Hebrew, Icelandic, Japanese, Kannada,
Korean, Latvian, Nepali, Persian, Romanian, Sanskrit,
Tamil, Thai, Turkish, Zulu...
● Many languages are genetically and typologically
unrelated
● http://www.globalwordnet.org

BabelNet: Combining WordNet & Wikipedia
Language Lemmas Synsets Word senses
English 5,938,324 3,032,406 6,550,579
Catalan 3,523,400 2,227,682 3,812,886
French 3,760,579 2,297,853 4,127,065
German 3,606,838 2,282,501 3,945,699
Italian 3,503,403 2,280,769 3,808,690
Spanish 3,629,457 2,265,189 3,976,233
Total 23,962,001 3,032,406 26,221,152
http://lcl.uniroma1/

CORNETTO
Combinatorial and Relational Network as
Toolkit for Dutch Language Technology
23

Lexical Unit (LU)
Correspond to wordmeaning
pair
form
morphology
syntax
semantics
pragmatics
usage examples
Spanish
Wordnet
Czech
Wordnet
French
Wordnet
Data Organization
German
Wordnet
Korean
Wordnet Arabic
Wordnet
Synonyms
Princeton
Wordnet
Synset
Model meaning relations
Wordnet
Domains
Internal relations
Collection of Terms and
Axioms
SUMO
24

and#1
(band)
Sumo: +HumanGroup
Domain: music
jazzband
(jazz band)
Combinatorics
in een band spelen
(to play in a band)
een band oprichten
(to start a band)
de band speelt
(the band plays)
groep
(group)
gezelschap
(group of people)
muziekgezelschap
(music group)
popgroep
(pop group)
artiest
(artist)
muzikant
(musician)
fietsband
(bike tire)
muziek
(music)
musiceren
(to make music)
Combinatorics
de band oppompen
(to pump air into a tire)
een band plakken
(to fi x a whole in a tire)
een lekke band
(fl at tire)
de band springt
(the tire explodes)
binnenband
(inner tire)
voorwerp (object)
ring (ring)
band#2
(tire)
Sumo: +Artifact
Domain: transport
zwemband
(tire for swimming)
Combinatorics
de band starten
(to start a tape)
op de band opnemen
(to record on tape)
de band afspelen
(to play from a tape)
buitenband
(outer tire)
lezen
(read)
autoband
(car tire)
middel (device)
informatiedrager
(data carrier) schrijven
(write)
geluidsdrager
(audio carrier)
band#3
(audio tape)
Sumo:+SignalCarrier
Domain: media
cassettebandje
(audio cassette)
Combinatorics
een goede/sterke band
(a good strong bond)
de banden verbreken
(to break all bonds)
een band hebben met iemand
(to have a bond with s.o.)
toestand (state)
relatie (relation)
verhouding
(relation)
band#5
(bond)
Sumo: +SocialRelation
Domain: psychology
familieband
(family bond)
bloedband
(blood bond)
moederband
(mother bond)

Dutch wordnet
Cornetto statistics
ALL NOUN VERB ADJECT.
Concepts 70,370 52,845 9,017 7,689
Word meanings 119,108 85,449 17,314 15,712
Lemmas
(form+pos)
92,686 70,315 9,051 12,288
Synonyms 103,762 75,475 14,138 12,914
Synonym per
concepts
Average number
meanings per word
1.47 1.43 1.57 1.68
1.12 1.07 1.56 1.05

Why do we need wordnets?
● So that machines can understand any natural
language and access all knowledge and
information expressed in natural language;
● So that humans can communicate with machines
using natural language and vice versa;
● To study philosophical and psychological
questions such as what is a word, what is a
concept;

Enabling technologies
● Semantic similarity: what expressions or
sentences are semantically similar?
● Semantic relatedness and textual entailment:
smoke entails fire, fire entails damage
● Word-Senses-Disambiguation

● Hirst–St-Onge (1998)
- d = direction changes
- C, k constants
Shortest path
- consider all relations → relatedness
● Leacock and Chodorov (1998)
- D = average depth
- only consider ISA → similarity

Images
● Computer Science and Artificial Intelligence Lab
(Massachusetts Institute of Technology, Torralba et al. 2008):
– database with 80 million tiny images from Google
Search
– Groups of 140 images sharing visual properties and
by Wordnet similarity based on all non-abstract
nouns
– http://groups.csail.mit.edu/vision/TinyImages/

(a) Query image.
(b) First 16 of 80
neighbors found using
k-nearest-neighbors
image similarity
measure.
(c) Ground truth
Wordnet branch
describing the content
of the query image at
multiple semantic
levels.
(d) Sub-tree formed by
accumulating branches
from all 80 neighbors.

● http://www.freesound.org/browse/
● Sound descriptors:
Sounds
– fast female footsteps on wood
– violin pizzicato with natural open strings
● Identifiable and non-identifiable source:
– bark, whinny, miaow, talk → classification by source
– click, clink, thud, screech, rattle → classification is more difficult (plop
=> noise => sound, plunk => sound)
● What features?
– Cognitive-perception: repetitiveness, continuousness, duration,
harmony, pitch
– Physical signal: spectral, temporal, frequency, etc.
● Semantically different events may perceptually sound similar: paper bag
vs eating toast

Language models and brain activity
Mitchel et al 2008, Predicting Human Brain Activity Associated with the
Meanings of Nouns, Science, vol 320

Experimental results