Transcript
Page 1: Bolette Sandford Pedersen, Sanni Nimb*, Anna Braasch University of Copenhagen,

Bolette Sandford Pedersen, Sanni Nimb*, Anna Braasch

University of Copenhagen, * Danish Society for Language and Literature

Merging specialist taxonomies and folk taxonomies in wordnets

- a case study of plants, animals, and foods in the Danish wordnet

Page 2: Bolette Sandford Pedersen, Sanni Nimb*, Anna Braasch University of Copenhagen,

LREC 2010 2

• Introduction to DanNet Food taxonomies in DanNet based on DDO: ideal cases and problems

• Interrelating natural and functional taxonomies in DanNet

• Conclusions

Outline

Page 3: Bolette Sandford Pedersen, Sanni Nimb*, Anna Braasch University of Copenhagen,

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• Joint work: University of Copenhagen & Society for Danish Language and Literature

• Monolingually-based approach:

Danish lexical sources based on corpora:

The Danish Dictionary (DDO); SIMPLE-DK

• International frameworks: Princeton WordNet, EuroWordNet

• 60,000 synsets ≈ concepts• 200,000 semantic relations• Open source – download: wordnet.dk

DanNet – a wordnet for Danish

Page 4: Bolette Sandford Pedersen, Sanni Nimb*, Anna Braasch University of Copenhagen,

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DDO

• Semi-automatic establishment of hyponym hierarchies by extraction of identified genus expressions in DDO

• Monolingual approach

Introduction

Page 5: Bolette Sandford Pedersen, Sanni Nimb*, Anna Braasch University of Copenhagen,

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Princeton WordNet: large number of e.g. fishes and vegetables, represented with both an animal or plant sense as well as a food sense

-> same goal for edible animals and plants in DanNet: 2 hierarchies with a high number of synsets

Food taxonomies in DanNet based on DDO: ideal cases and problems

Page 6: Bolette Sandford Pedersen, Sanni Nimb*, Anna Braasch University of Copenhagen,

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Food taxonomies in DanNet based on DDO: ideal cases and problems

Reuse of DDO, ideal cases : edible plants and animals should have two

separate senses in DDO with two different genus expressions:

1= plant/animal. Biological genus expression = ”animal”, ”plant”, ”part of animal”, ”part of plant” …

2= food. Functional genus expression = ”food”, ”meat”, ”vegetable” …

Page 7: Bolette Sandford Pedersen, Sanni Nimb*, Anna Braasch University of Copenhagen,

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Food taxonomies in DanNet based on DDO: ideal cases and problems

Genus expression sense 1= gallinaceous bird

Genus expression sense 2 = meat

(turkey)

Page 8: Bolette Sandford Pedersen, Sanni Nimb*, Anna Braasch University of Copenhagen,

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Food taxonomies in DanNet based on DDO: ideal cases and problems

artichoke:• only one sense • genus expression: flower bud• part of definition: edible, but no food sense

established

Study: 74 DDO lemmas with polysemy plant/animal and food Conclusion: More than half demand manual treatment. Why?

(edible)(flower bud)

(artichoke)

Page 9: Bolette Sandford Pedersen, Sanni Nimb*, Anna Braasch University of Copenhagen,

LREC 2010

Food taxonomies in DanNet based on DDO : ideal cases and problems

1. DDO = traditional -> zoological and botanical domains strongly influenced by professional descriptions:

• Preference given to biological senses (in spite of corpus evidence)

• Genus expression: Botanical/zoological terminology (tomato = fruit, spinach = herb, pheasant = gallinacean )

2. First version of DDO - a printed dictionary -> food sense left out due to space limits

3. DDO not ontology-driven -> descriptions made ´bottom up’. -> No predefined vocabulary of definition-> No systematic treatment of regular polysemy

Page 10: Bolette Sandford Pedersen, Sanni Nimb*, Anna Braasch University of Copenhagen,

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‘Physical’ versus ‘functional’ genus expressions

• Observation: DDO definitions of concrete objects tend to use a ‘physical’ genus expression (object, stick , ball ..)

-> few ’functional’ genus expressions (toy, tool, equipment, food..)

Examples, Princeton WordNet:

‘ball’ = round object that is hit or thrown or kicked in games’BUT hypernym in WordNet = game equipment (NOT object)

‘doll = a small replica of a person, used as a toy’. BUT hypernym in WordNet = toy (NOT replica)

• Conclusion: Genus expressions are not fully reliable for the establishment of functional hierarchies

Page 11: Bolette Sandford Pedersen, Sanni Nimb*, Anna Braasch University of Copenhagen,

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Interrelating taxonomies in DanNet

Task of DanNet editors:

• Establish regular polysemous synsets where missing in DDO in order to account for layman’s food perspective

• Harmonize the different DDO approaches in a consistent way

• Ensure that clash of taxonomies does not mess up the general structure of the network

Page 12: Bolette Sandford Pedersen, Sanni Nimb*, Anna Braasch University of Copenhagen,

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Harmonize the different DDO approaches in a consistent way

We strive towards individual, but interrelated taxonomies in DanNet:

Food taxonomy of meat, vegetables and fruit i.e. FUNCTIONAL KINDS in Cruse’s

terminology (Cruse 2002)

Botanical/zoological taxonomies (in practice incomplete)

i.e. NATURAL KINDS in Cruse’s terminology

Page 13: Bolette Sandford Pedersen, Sanni Nimb*, Anna Braasch University of Copenhagen,

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Interrelating taxonomies

Encoding strategy in DanNet:Synsets interrelate with the two taxonomies either

By means of regular polysemy Example: lamb_1 (animal), lamb_2 (meat: food)

or

By means of multiple inheritance Examples: tomato (fruit/part-of-plant AND vegetable: food) rubarb (stalk/part-of-plant AND fruit: food)

Page 14: Bolette Sandford Pedersen, Sanni Nimb*, Anna Braasch University of Copenhagen,

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Interrelating taxonomies

lamb_1

tomato_1

vegetablefruit

lamb_2

meat

Zoological Food

Botanical Food

animal

Regular polysemy

Page 15: Bolette Sandford Pedersen, Sanni Nimb*, Anna Braasch University of Copenhagen,

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Not all concepts represented in both taxonomies

Only in food taxonomy:

grøntsag (vegetable) rodfrugt (root

vegetable) krydderurt (spice herb) suppeurt (potherb) vildt (game) flæsk (pork) indmad (offals)

Only in natural taxonomy:

plante (plant) skærmplante

(umbelliferous plant) rod (tuber) stilk (stalk) indvolde (entrails)

Page 16: Bolette Sandford Pedersen, Sanni Nimb*, Anna Braasch University of Copenhagen,

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Tricky cases (≈ false friends)

Examples of these are such as frugt (fruit) nød (nut) bær (berry)

In principle, these cases should evoke two (unrelated) synsets, one in each taxonomy

if you actually encode also the botanical ones

Page 17: Bolette Sandford Pedersen, Sanni Nimb*, Anna Braasch University of Copenhagen,

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Excerpt from Food taxonomy (offals and meat)

Page 18: Bolette Sandford Pedersen, Sanni Nimb*, Anna Braasch University of Copenhagen,

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Offals and their relations

Page 19: Bolette Sandford Pedersen, Sanni Nimb*, Anna Braasch University of Copenhagen,

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Conclusions (1)

Foods taxonomies are typically folk taxonomies emerged spontaneously depending on the goods available and on cooking traditions of a particular region.

Inspired by and related to botanical and zoological taxonomies

The fact that terms are taken over from these natural taxonomies causes problems that require a consistent framework

Monolingual dictionaries do not always have a clear strategy

Page 20: Bolette Sandford Pedersen, Sanni Nimb*, Anna Braasch University of Copenhagen,

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Conclusions (2)

We have developed a framework that enables to distinguish and interrelate between the natural taxonomies and the functional taxonomies of the network.

Even if you have monolingual lexical resources that are inconsistent in this respect, the monolingual starting point is important in order to capture correct conceptual structures of a given language

Work in progress! See wordnet.dk and andreord.dk


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