semantic wikipedia the missing links

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Denny VrandečićAIFB, Universität Karlsruhe (TH)Semantics 2006Vienna, November 28th, 2006

Semantic Wikipedia The missing links

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Universal Access toAll Knowledge

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MarryingWikipedia and the Semantic Web

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Overview

Background Wikis, Wikipedia, and the Semantic Web

Semantic Wikipedia Idea, How it looks like, Advantages

Challenges and Opportunities Web ecosystem, Open issues, Next steps

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Wikis

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Long, long time ago…

Using Pattern Languages for Object Oriented Programming, OOPSLA87

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Design Patterns

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Design Patterns Web Page

HTML

Simple SyntaxH

TM

L

HTML

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Wikis Everyone can edit

Technology allows to edit Syntax is easy to learn

History of edits Recent changes Community building / Attribution

Easy to revert Important for fighting vandalism No fear of breaking the system

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Wikipedia

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A new encyclopedia

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Created March 2000 Free, web based encyclopedia

Everyone can read Expert authors and editors Extensive formal peer review Until January 2001: 22 articles Side project: wiki-based Nupedia

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Created March 2000 Free, web based encyclopedia

Everyone can read Expert authors and editors Extensive formal peer review Until January 2001: 22 articles Until January 2002: 20,342 articles in

17 languages, 17,307 in English

January 2001

edit

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Wikipedia growth

Year Articles English Languages

2002 20,342 17,307 17

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Wikipedia growth


2002 20,342 17,307 17

2003 133,129 98,475 25

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Wikipedia growth


2002 20,342 17,307 17

2003 133,129 98,475 25

2004 420,562 189,124 52

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Wikipedia growth


2002 20,342 17,307 17

2003 133,129 98,475 25

2004 420,562 189,124 52

2005 1,311,697 438,289 162

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Wikipedia growth


2002 20,342 17,307 17

2003 133,129 98,475 25

2004 420,562 189,124 52

2005 1,311,697 438,289 162

2006 3,100,360 893,237 197

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Wikipedia growth


2002 20,342 17,307 17

2003 133,129 98,475 25

2004 420,562 189,124 52

2005 1,311,697 438,289 162

2006 3,100,360 893,237 197

11/2006 5,565,830 1,462,910 250

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Wikipedia users

2.7 Mio registered users About 70,000 contributors 2% (1,400) make 73.4% of all edits

Most content from wide user base Clean up / “gardening” by small group

[English Wikipedia, study by Aaron Swartz]

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Wikipedia’s problems

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But it can’t work!

Everyone can edit Repairing is easier than breaking

No special status for experts Community building

Nature study on quality 4 / 3 error rate Wikipedia / EB Controversial

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Quality

Hard to discover factual errors Focusing on quality Repeated facts Big number of lists But still not all “interesting” lists

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Coverage by language

English: 1.5 Mio German: 0.5 Mio 10 more languages: 100.000+ 40 more languages: 10.000+ But what about other languages?

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Semantic Web

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Angola Africalocated in

Zambia

located in

borders

Country Continent

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http://wiki.ontoworld.org/index.php/_Angolahttp://wiki.ontoworld.org/index.php/_Africa

http://wiki.ontoworld.org/index.php/_Relation-3ALocated_in

http://wiki.ontoworld.org/index.php/_Zambia

http://w

iki.ontoworld

.org/index.p

hp/_Relation-3ALoca

ted_in

http://wiki.ontow

orld.org/index.php/_Relation-3A

Borders

http://wiki.ontoworld.org/index.php/_Category-3ACountry

http://wiki.ontoworld.org/index.php/_Category-3AContinent

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http://w

iki.ontoworld

.org/index.p

hp/_Relation-3ALoca

ted_in

http://wiki.ontow


Borders



Angola

http://www.w3.org/2000/01/rdf-schema#label

Africa

Located in

Zambia

Country

Borders

Continent

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Zambia

located in

borders

Country Continent

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Zambia

located in

borders

Country Continent

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Semantic Wikipedia: Idea

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Wikipedia today

Brač is a Croatian island in the Adriatic Sea. The island has a population of 13,000, living in numerous little towns, ranging from the 'main town' Supetar, with more than 2,500 inhabitants, to Novo Selo, where only a dozen people live.

Today, Brač lives mostly on tourism, but fishing and agriculture (especially wine and olives) are very important too, as is selling its precious, white stone (which was used in building Diocletian's Palace in Split, and is built into the White House in Washington, DC, too).

Category: Croatian Island

http://en.wikipedia.org/wiki/Croatia

http://en.wikipedia.org/wiki/Adriatic_Sea

http://en.wikipedia.org/w/index.php?title=Supetar&action=edit

http://en.wikipedia.org/wiki/Novo_Selo

http://en.wikipedia.org/wiki/Novo_Selo

http://en.wikipedia.org/wiki/Tourism

http://en.wikipedia.org/wiki/Fishing

http://en.wikipedia.org/wiki/Agriculture

http://en.wikipedia.org/wiki/Wine

http://en.wikipedia.org/wiki/Olive

http://en.wikipedia.org/wiki/Diocletian%27s_Palace

http://en.wikipedia.org/wiki/Split

http://en.wikipedia.org/wiki/White_House



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BračBrač

CroatiaCroatia

Adriatic SeaAdriatic Sea

ItalyItaly

tourismtourism

ZagrebZagreb SplitSplit

MontenegroMontenegro

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How are they linked?

Brač Croatia

Brač Adriatic Sea

Brač Supetar

Brač Novo Selo

Brač tourism

Brač fishing

Brač agriculture

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Brač belongs to Croatia

Brač Adriatic Sea

Brač Supetar

Brač Novo Selo

Brač tourism

Brač fishing

Brač agriculture

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Brač located in Adriatic Sea

Brač Supetar

Brač Novo Selo

Brač tourism

Brač fishing

Brač agriculture

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Brač has town Supetar

Brač has town Novo Selo

Brač tourism

Brač fishing

Brač agriculture

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Brač has town Supetar

Brač has town Novo Selo

Brač lives on tourism

Brač lives on fishing

Brač lives on agriculture

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Brač is a

[[Croatia]]n island with an area of 396 km².

Brač is a

[[belongs to::Croatia]]n island with an area of [[area:=396 km²]].

Typed links Extend wiki with typed links So the computer “understands” it

Brač Croatiabelongsto

area396 km²

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How does it look like?

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Advantages

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Many pages answer questions list of female tennis players asteroids named after people countries sorted by area, population, …

They can be generated automatically Less maintenance tasks Higher consistency

Automatic tables and lists

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Inline queries<ask>[[Category:Country]][[located in::Africa]][[population:=>1,000,000]][[population:=<10,000,000]][[population:=*]][[area:=*km²]][[borders::*]]

</ask>

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Inline query results

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Ontoworld

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Ontoworld

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Does every country have one capital? Is there a person with more than one

mother? Is every person born before dying? Does the population density fit to

population and size?

Hand crafted checks

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Multilinguality

Automatic check of consistency over language boundaries

Generating pages for smaller Wikipedias?

Browsing information in different languages

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Web ecosystem

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Wikipedia as a vocabulary

Semantic Wikipedia as a resource of URIs Maintaining good URIs is hard

Documented Multilingual labels Enables easier mapping

Reuse for common terms Helps in mapping the rest structurally

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ChrissieChrissieRobertJordan

RobertJordan

TillTill

fanfr

ien

d

14,95 €14,95 €

price

Wheel ofTime

Wheel ofTime

auth

or o

fsuggestT

ill lo

oks

for

a gi

ftfo

r C

hris

sie,

for

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€Scenario: looking for gifts

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Wikipedia as knowledge base

Tools already integrate Wikipedia articles

Bits of knowledge make more sense!

Amarok with knowledge import instead full articles?

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Use Semantic Web tools

Integration of data Querying

SPARQL endpoints Browsing

Faceted browsers Visualization

Timeline

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SMW installations Ontoworld sem’base WWW2006 & ESWC2006 Wiki Semantic Karlsruhe KM Bible wiki Esoteric knowledge wiki Wikicompany JurisPedia …

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Open issues

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Convergence of vocabulary

Consistency of vocabulary Author of, has written, creator…

Documentation of all types Visual feedback: red and blue links

Queries: consistent vocabulary needed Autocompletion? UI hints?

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NLP and Semantic Wikipedia

Suggestion / learning of relationships Based on patterns Statistical Background knowledge

Good playground for evaluations

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Simpler User Interface

WYSIWYG Interface for MediaWiki is in development

How to integrate with Semantic Extension?

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Lack of expressivity

How to say “Ronald Reagan was US president from 1980 to 1988”?

What about relations between relations, like inverses?

What about transitivity, symmetry? What about constraints like class

disjointness?

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Next steps

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Next steps

Marry Wikipedia and Semantic Web Need to run stress tests

Wikipedia at 12,000 hits per second Scalability,

scalability, scalability Show cool apps Multilinguality Tons of details

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Conclusions

Very flexible system for creating data “Soft” introduction

People often scared about Semantic Web You can still use it as a standard wiki Immediate benefit

“The simplest database that could work” Data is there – play with it! Kickstart the Semantic Web

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Thank you!

ontoworld.org

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Conclusions

Very flexible system for creating data “Soft” introduction

People often scared about Semantic Web You can still use it as a standard wiki Immediate benefit

“The simplest database that could work” Data is there – play with it! Kickstart the Semantic Web

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Backup slides

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Technicalities

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MediaWiki

Runs Wikipedia Active development Scalable Easy to use and powerful PHP / MySQL Not many SemWeb tools here

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Mapping of OWL to SMW

owl:Individual Article

owl:Class Category

owl:ObjectProperty Relation, Link type

owl:DatatypeProperty Attribute

Object property instance Typed link [[property::object]]

Datatype property instance [[property:=value]]

rdf:type class Class instantiation

[[Category:class]]

(on article page)rdfs:subClassOf class

Subsumption

[[Category:class]]

(on category page)

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Reuse vocabulary

Existing vocabulary can be mapped Wiki directly usable as data source

No external mapping required Define vocabulary and mapping But: no complex mappings

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Reuse in a Webpage

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Zambia

located in

borders

Country Continent

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http://w

iki.ontoworld

.org/index.p

hp/_Relation-3ALoca

ted_in

http://wiki.ontow


Borders



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http://w

iki.ontoworld

.org/index.p

hp/_Relation-3ALoca

ted_in

http://wiki.ontow


Borders



Angola


Africa

Located in

Zambia

Country

Borders

Continent

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Zambia

located in

borders

Country Continent

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http://w

iki.ontoworld

.org/index.p

hp/_Relation-3ALoca

ted_in

http://wiki.ontow


Borders



Angola


Africa

Located in

Zambia

Country

Borders

Continent

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SPARQL : RDF Query LangPREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>PREFIX thing: <http://wiki.ontoworld.org/index.php/_>PREFIX relation: <http://wiki.ontoworld.org/index.php/_Relation-3A>

SELECT ?labelWHERE { thing:Angola relation:Located_in ?c . ?c rdfs:label ?label}

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http://w

iki.ontoworld

.org/index.p

hp/_Relation-3ALoca

ted_in

http://wiki.ontow


Borders



Angola


Africa

Located in

Zambia

Country

Borders

Continent

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<html> <body> Angola is in <?php define("RDFAPI_INCLUDE_DIR", "path/api/"); include(RDFAPI_INCLUDE_DIR . "RDFAPI.php");

$model = ModelFactory::getDefaultModel(); $model->load("full URI/ExportRDF/Angola"); $result = $model->sparqlQuery('SPARQL'); $value = $result[0]['?label']; echo $value->getLabel(); ?> </body></html>

Angola is in Africa.

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TBox engineering

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Full TBox engineering?

Not meant for it, but possible Does not capture semantics Does not propagate to categories

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Reified ontologies

SubclassOfAxiom1

meta:Populated

place

meta:City

refers

subclass

supe

rclas

s

subclass of

refers

Populated place

City

meta:subclassO

f

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Reified ontologies

SubclassOfAxiom1

meta:Populated

place

meta:City

subclass

supe

rclas

s

subclass of

Populated place

City

meta:subclassO

f

owltools

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Everything can be discussed

All pages have a discussion page All individuals, classes, properties have

a page With reification, even axioms may have

a page Very fine grained discussion possible

Opinions can be formalized explicitly

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Ontology import

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Ontology import

Reuse existing ontologies Upload mapped ontologies Kickstart a wiki Circumvent empty sheet problem Enrich an existing wiki

Only the simple parts

owl:Individual Article

owl:Class Category

owl:ObjectProperty Relation, Link type

owl:DatatypeProperty Attribute

Object property instance Typed link [[property::object]]

Datatype property instance

[[property::value]]

rdf:type class Class instantiation

[[Category:class]]

On article page

rdfs:subClassOf class

Subsumption

[[Category:class]]

On category page

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Reasoning wikis

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Dynamics

SemanticMediaWiki

SemanticMediaWiki KAON2KAON2User

Browser

UserBrowser

edit articlecheck for consistency

consistent?

warn if inconsistent

Example:-wife of has domain Woman-Woman and Man are disjoint

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Mockup screen

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Automatic classification

Infer categories from statements Based on background ontology and

wiki knowledge Automatic classification of articles Can be reused in queries

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Mockup screen

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URI crisis resolved?

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URIs for everything

Uniform Resource Identifiers Based on known protocols

Linked data: resolve URI for description Maintaining URIs is hard

Clutter namespace Setting up descriptions Persistence Reuse and mapping

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Romeo and JulietRomeo and Juliet

URI crisis

Is “Romeo and Juliet” the book, or the article about the book?

One URI for each Mind the gap! Redirects in

browser

Shakespeareauthor

JSmith 42

author

abou

t

http://en.wikipedia.org/wiki/Romeo_and_Juliet

http://en.wikipedia.org/wiki/_Romeo_and_Juliet

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Bug status: still open

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Slides index – Backup slides

103 – Technicalities111 – Reuse in webpages124 – TBox engineering129 – Ontology import132 – Reasoning in wikis137 – URI crisis resolved

19 – Wikipedia 49 – Semantic Web 56 – Basic idea 74 – Advantages 91 – Open issues101 – Conclusions

semantic wikipedia the missing links

Documents

web based encyclopediaeveryone

small groupenglish wikipedia

readexpert authors

wikibased nupedia

croatian island

object oriented programming

factual errorsfocusing

breakingno special status