By:-Govind Raj

IT/1001227464

WORDNETA Lexical Knowledgebase

Topics of DiscussionWhat is WORDNET?????International Scenarios.Design fundamentals.Major Lexical Relations.Uses of Wordnet.Wordnets in India.

What is WORDNET?????WordNet  is a lexical database  for

the English language based on conceptual look-up.

George A. Miller who began the WordNet project in the mid 1980s.

Organizes lexical information in terms of word meanings rather than word form.

Wordnet can also be used as a thesaurus.

Miller on Wordnet“In terms of coverage, WordNet’s goals differ little from those of a good standard college-level dictionary, and the semantics of WordNet is based on the notion of word sense that lexicographers have traditionally used in writing dictionaries. ”

Wordnet: International ScenarioWordnet is a network of words linked by

lexical and semantic relations.The first wordnet in the world was for

English developed at Princeton over 15 years.

The Eurowordnet- linked structure of European language wordnet was built in 1998 over 3 years.

Wordnets for Hindi and Marathi being built at IIT Bombay are amongst the first IL wordnet.

All these are proposed to be linked into the IndoWordnet which eventually will be linked to the English and the Euro wordnet.

Can canary sing? – pretty fast response.Can canary fly ? – a bit slower response.Does canary have skin ? – a slow response.

Psycholinguistic Theory

Animal

Bird

Canary

Syntagmatic VS Paradigmatic ???Syntagmatic – when words appear together in a

unit.Paradigmatic – if words are linked in a lexical

resource

When we hear a word , many words come to our mind through association.

For cat :animal , mammal – Paradigmatic

mew , purr , furry - Syntagmatic

Fundamental Design Questions

Major Lexical RelationsSynonymyPolysemyMetonymyHyponymy/ HypernymyMeronymy/ HolonymyAntonymy

SynonymyDifferent ways of expressing related

conceptsExamples

cat, feline, Siamese catOverlaps with basic and subordinate

levelsSynonyms are almost never truly

substitutableUsed in different contextsHave different implications

This is a point of contention

PolysemyMost words have more than one senseHomonym: same sound and/or spelling,

different meaningbank (river)bank (financial)

Polysemy: different senses of same wordThat dog has floppy ears.She has a good ear for jazz.bank (financial) has several related senses

the building, the institution, the notion of where money is stored

MetonomyUse one aspect of something to stand for the

wholeThe building stands for the institution of the

bank.Library stands for a whole set of books ..Mostly all collective nouns came under this.

HyponymyISA relationRelated to Super ordinate and Subordinate

level categorieshyponym(robin , bird)hyponym(emu, bird)hyponym(bird, animal)hypernym(animal , bird)

A is a hypernym of B if B is a type of AA is a hyponym of B if A is a type of B

HolonomyPart/Whole relation

meronym(beak , bird)meronym(bark , tree)holonym(tree , bark)

Transitive conceptually but not lexicallyThe knob is a part of the door.The door is a part of the house.The knob is a part of the house

Holonyms are (approximately) the inverse of meronyms

AntonymyLexical opposites

antonym(large, small)antonym(big, small)antonym(big, little)but not large, little

Many antonymous relations can be reliably detected by looking for statistical correlations in large text collections.

Gloss

study

Hyponymy

Hyponymy

Dwelling,abode

bedroom

kitchen

house,home

A place that serves as the living quarters of one or mor efamilies

guestroom

veranda

bckyard

hermitage cottage

Meronymy

Hyponymy

Meronymy

Hypernymy

WordNet Sub-Graph (English)

Structure of Wordnet

Uses: Word sense disambiguation. Information retrieval. Automatic text classification. Automatic text summarization. Machine translation Automatic crossword puzzle generation. Improve search engine results

WordNet : Size

POS Unique Synsets Strings

Noun 114648 79689

Verb 11306 13508

Adjective 21436 18563

Adverb 4669 3664

Totals 152059 115424

WordNet Uses “Synsets” – sets of synonymous terms

Hindi Wordnet

Dravidian Language Wordnets

North East Language Wordnet

Marathi Wordnet

Sanskrit Wordnet

EnglishWordnet

Bengali Wordnet

Punjabi Wordnet

KonkaniWordnet

Linked Wordnets in India