Semantic wikis

1. Semantic Wikis
Valentin Sviridov
13/12/2013 COMASIC M2 2013 - Web Sémantique 1
Some parts are taken from “Semantic Wikipedia”
presentation by Aaron Gallant and Sung Kim

2. Plan
• Introduction
– Why bother?
– What is Semantic Wiki?
– History and people behind
• Practical point of view
– How does it work?
– How is it used?
• Conclusion
– How to take part?
– Q&A
13/12/2013 COMASIC M2 2013 - Web Sémantique 2

3. Why bother?
• Traditional Wiki problems
– Data coherency
– Data access
– External data usage
– Tags/categories hell
• Export to RDF
13/12/2013 COMASIC M2 2013 - Web Sémantique 3

4. What is Semantic Wiki?
• Model of knowledge
– Machine processing is possible
• Regular Wiki
– Structured text and untyped hyperlinks
• Semantic Wiki
– Identifiable information with typed hyperlinks
– Metadata
13/12/2013 COMASIC M2 2013 - Web Sémantique 4

5. MediaWiki Structures
• Wiki Text: Markup language
– Relation between entities
• Hyperlinks : Redirect to different pages
– [[PAGE_NAME]]
• Category: classify pages and gives structures
– [[Category: CATEGORY_NAME]]
• Synonymous
– Redirect mechanism
• Homonymous
– Disambiguation page
13/12/2013 COMASIC M2 2013 - Web Sémantique 5

6. MediaWiki Structures
13/12/2013 COMASIC M2 2013 - Web Sémantique 6

7. Category
13/12/2013 COMASIC M2 2013 - Web Sémantique 7

8. Semantics: Shaken, not Stirred
13/12/2013 COMASIC M2 2013 - Web Sémantique 8

9. Typical features and examples
• Features
– Relate data (X is author of Y)
– Assign attributes to pages
– Search and filter (list of books published in French in
1965)
– Automatic updates of dependent pages
• Usage examples
– Bibliography
– Genealogy
– Catalogues
– Biology-related databases
13/12/2013 COMASIC M2 2013 - Web Sémantique 9

10. History
• 2001 – Wikipedia launched
• 2003 – Mention of Semantic Wiki
– L. Sauermann. The Gnowsis – Using Semantic Web
Technologies to build a Semantic Desktop. Master’s
thesis, Vienna University of Technology, 2003.
• Middle of 2000s
– PlatypusWiki (2004); Rhizome (2005); IkeWiki (2006); OntoWiki (2006)
• Today
– Semantic MediaWiki is the most widely used
13/12/2013 COMASIC M2 2013 - Web Sémantique 10

11. People
• Tim Berners-Lee
– Web creator
– Coined Semantic Web term
• Jimmy Wales and Larry Sanger
– Wikipedia project
• Markus Krötzsch, Denny Vrandečić and Max
Völkel
– Semantic MediaWiki in 2005
• Agile Knowledge Engineering and Semantic
Web (AKSW) research group, University of
Leipzig
– DBpedia and OntoWiki
13/12/2013 COMASIC M2 2013 - Web Sémantique 11

12. How does it work?
• Semantics included or placed separately
• Syntax: Wiki, OWL, RDF
• Ontologies: internal or “standard” ones
• Some wikis provide querying and reasoning
support
13/12/2013 COMASIC M2 2013 - Web Sémantique 12

13. How is it used?
• Show similar articles
• Derived information
– Place in the hierarchy
• Browse link types: show all capitals
• Semantic search
– SPARQL
– Usual search + refinement
13/12/2013 COMASIC M2 2013 - Web Sémantique 13

14. Wild nature Semantic Wikis
• Public wikis
• Internal usage
13/12/2013 COMASIC M2 2013 - Web Sémantique 14

15. Semantic Wiki engines
• Semantic MediaWiki
– Semantic Forms
– Semantic Result Formats
– Semantic Maps
• Ontowiki
13/12/2013 COMASIC M2 2013 - Web Sémantique 15

16. Semantic MediaWiki
• Extension to MediaWiki: special annotations
• Features
– Automatically-generated lists
– Visual display of information (maps, graphs, …)
– More simple data structure (no “1620s births” any more)
– Searching
– External use: CVS, JSON, SPARQL, RDF
• Syntax: [[Property name: Value]]
– Hyperlinks
• E.g. London  [[capital of: England]]
– Data value
• E.g. London  [[Population: 7,421,328]]
13/12/2013 COMASIC M2 2013 - Web Sémantique 16

17. Properties
• Predefined Properties
• Custom Properties
– Declare Properties
• Property Namespace
– E.g. Property: Population
• Define property’s type with has type: attribute
– Possible data types: “String”, “Date”, “Geographic Coordinate”,
“URL”
– E.g. Population  [[has type: Number]]
• Units Definition, Value validation, Property Hierarchy,
etc.
13/12/2013 COMASIC M2 2013 - Web Sémantique 17

18. OWL Conversion
• OWL/RDF
– Wiki Page = OWL abstract entity
– Property = OWL property
– Category = OWL class
13/12/2013 COMASIC M2 2013 - Web Sémantique 18

19. Example
13/12/2013 COMASIC M2 2013 - Web Sémantique 19
Text written with MediaWiki
Text written with Semantic MediaWiki

20. Querying
– Query results and output as part of the wiki
text
– #ask function
13/12/2013 COMASIC M2 2013 - Web Sémantique 20
 Query Condition
 Output Values
{{#ask:
[[Category:City]] [[located in::Germany]]
| ?population | ?area#km² = Size in km²
}}

21. Export
13/12/2013 COMASIC M2 2013 - Web Sémantique 21

22. What can you do?
• Research
– Data extraction techniques
– Ontologies
• Pass a message
13/12/2013 COMASIC M2 2013 - Web Sémantique 22

23. Web 3.0?
• People keep asking what Web 3.0 is. I think
maybe when you've got an overlay of scalable
vector graphics – everything rippling and
folding and looking misty – on Web 2.0 and
access to a semantic Web integrated across a
huge space of data, you'll have access to an
unbelievable data resource ...
Tim Berners-Lee, 2006
13/12/2013 COMASIC M2 2013 - Web Sémantique 23

24. Questions?
13/12/2013 COMASIC M2 2013 - Web Sémantique 24