do we need lexicographers? prospects for automatic lexicography adam kilgarriff lexical computing...

Do we need lexicographers?Prospects for automatic

lexicography

Adam Kilgarriff

Lexical Computing Ltd

University of Leeds

UK

Bolzano, May 2012 Adam Kilgarriff 2

Outline

Precision and recall Between corpus and dictionary Shopping list Conclusions

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Find me all the fat cats

a request for information

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High recall

Lots of responses Maybe not all good

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High precision

Fewer hits Higher confidence

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Information-seeking

Recall Precision

Computers good bad

People bad good

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Cyborg: part-human, part-computer

Treat your computer with respect. You and it can do great things

together.

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Lexicography: finding facts about words

Shopping list collocations grammatical patterns examples synonyms labels

– region– domain– register

translations meanings

Szeged, Jan 2008 Kilgarriff, Global WordNet 9

What is a word sense (1) SFIP

– Sufficiently frequent insufficiently predictable

(a glass of) whisky x (a glass of) tequila

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What is a word sense (2)

homonymy

analogy polysemy rules

collocation

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What is a word sense (3) A cluster

– Of instances of use Operationalised as: corpus lines

– Clustered by lexicographers

Szeged, Jan 2008 Kilgarriff, Global WordNet 12

What is a word sense (3)

Szeged, Jan 2008 Kilgarriff, Global WordNet 13

What is a word sense (3)

Szeged, Jan 2008 Kilgarriff, Global WordNet 14

What is a word sense (3)

Szeged, Jan 2008 Kilgarriff, Global WordNet 15

What is a word sense (3)

Szeged, Jan 2008 Kilgarriff, Global WordNet 16

What is a word sense (3) A cluster

– Of instances of use Operationalised as: corpus lines

– Clustered by lexicographers Makes sense of

– Overlapping senses– Different dictionaries, different senses– Lumping and splitting

Szeged, Jan 2008 Kilgarriff, Global WordNet 17

I don’t believe in word senses

Believe in:– resurrection ghost witch vampire god miracle

fairy Philosophy:

– Ontological commitment– (same meaning different register)

“good entities to build belief systems on”

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But I’m an NLP person Automatic clustering? Inspiration:

– Hindle 1991, Schütze 1993, Grefenstette 1993, Lin 1999

– You can get semantic sense from corpora+stats

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First attempt Longman 1994 Abject failure

– No grammar– Corpus too small and noisy– Naïve clustering– Useless programmer

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Second attempt SENSEVALS 1998, 2001, 2004… mitigated failure

– Rarely over two thirds correct

Szeged, Jan 2008 Kilgarriff, Global WordNet 21

Third attempt SADD (semi-automatic dictionary

drafting) 2008 With Pavel Rychly I thought I knew what I was doing but

– Probably a failure

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Collocations Easy

– Most words don’t go with most other words

Then build on what we can do well (metaphor, analogy, homonymy, rules:

all much harder)

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Lexicography: finding facts about words

Shopping list

collocations grammatical patterns examples synonyms labels

– region– domain– register

translations meanings

Yes

Yes

Yes

Yes

YesYes

Yes

Yes

?

No

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Thank you

http://www.sketchengine.co.uk