From Wikipedia, the free encyclopedia Semantic wiki
Semantic wiki
A semantic wiki is a wiki that has an underlying model of automatically generate a list of fruits, simply by listing all
the knowledge described in its pages. Regular, or syntac- pages that are tagged as being of type "fruit." Further se-
tic, wikis have structured text and untyped hyperlinks. mantic tags in the "apple" page could indicate other da-
Semantic wikis, on the other hand, provide the ability ta about apples, including their possible colors and sizes,
to capture or identify information about the data within nutritional information and serving suggestions, and so
pages, and the relationships between pages, in ways that on.
can be queried or exported like a database.[1][2] If the wiki exports all this data in RDF or a similar for-
Semantic wikis were first proposed in the early 2000s, mat, it can then be queried in a similar way to a database
and began to be implemented seriously around 2005. As - so that an external user or site could, for instance, re-
of 2011, the best-known semantic wiki software may be quest a list of all fruits that are red and can be baked in a
Semantic MediaWiki, while the best-known standalone pie.
semantic wiki may be Freebase.
History
Key characteristics In the 1980s, before the Web began, there were several
technologies to process typed links between collectively
Formal notation maintained hypertext pages, such as NoteCards, KMS and
The knowledge model found in a semantic wiki is typi- gIBIS. Extensive research was published on these tools
cally available in a formal language, so that machines can by the collaboration software, computer-mediated com-
process it into an entity-relationship or relational data- munication, hypertext, and computer supported cooper-
base. ative work communities.
The formal notation may be included in the pages The first known usage of the term "Semantic Wiki"
themselves by users, as in Semantic MediaWiki, or it may was a Usenet posting by Andy Dingley in January 2001.[3]
be derived from the pages or the page names or the Its first known appearance in a technical paper was in a
means of linking. For instance, using a specific alterna- 2003 paper by Austrian researcher Leo Sauermann.[4]
tive page name might indicate that a specific type of link Many of the existing semantic wiki applications were
was intended. This is especially common in wikis devot- started in the mid-2000s, including Semantic MediaWiki
ed to code projects. It should be easy to examine and fix, (2005), Freebase (2005) and OntoWiki (2006).
e.g. to identify problems in parsing and conventions in- June 2006 saw the first meeting dedicated to semantic
troduced by newer users. wikis, "SemWiki2006", co-located with the European Se-
In either case, providing information through a for- mantic Web Conference in Montenegro.[5]
mal notation allows machines to calculate new facts (e.g. The site DBpedia, launched in 2007, though not a se-
relations between pages) from the facts represented in mantic wiki, publishes structured data from Wikipedia
the knowledge model. in RDF form, which enables semantic querying of
Wikipedia’s data.
Semantic Web compatibility In March 2008, Wikia, the world’s largest wiki farm,
The technologies developed by the Semantic Web com- made the use of Semantic MediaWiki available for all
munity provide one basis for formal reasoning about the their wikis, thus allowing all the wikis they hosted to
knowledge model that is developed by importing this da- function as semantic wikis.[6]
ta. However, there are also a wide array of technologies In July 2010, Google purchased Metaweb, the compa-
that work on ERD or relational data. ny behind Freebase.[7]
Example Semantic wiki software
Imagine a semantic wiki devoted to food. The page for an See also Category: Semantic wiki software
apple would contain, in addition to standard text infor- There are a number of wiki applications that provide se-
mation, some machine-readable or at least machine-in- mantic functionality. Some standalone semantic wiki ap-
tuitable semantic data. The most basic kind of data would plications exist, including OntoWiki. Other semantic wi-
be that an apple is a kind of fruit - what’s known as an ki software is structured as extensions or plugins to stan-
inheritance relationship. The wiki would thus be able to dard wiki software. The best-known of these is Semantic
1
From Wikipedia, the free encyclopedia Semantic wiki
MediaWiki, an extension to MediaWiki. SMW+ is a soft- coordinates and number values, in various formats, such
ware package that includes Semantic MediaWiki. as graphs, tables, charts, calendars and maps.
Some standard wiki engines also include the ability
to add typed, semantic links to pages, including PhpWiki
and Tiki Wiki CMS Groupware.
See also
Freebase, though not billed as a wiki engine, is a web • Microformats
database with semantic-wiki-like properties. • Ontology
• RDF, RDFS, OWL, SPARQL
• Business Intelligence 2.0 (BI 2.0)
Common features • Wikis:
Semantic wikis vary in their degree of formalization. Se- • Familypedia
mantics may be either included in, or placed separately • Freebase
from, the wiki markup. Users may be supported when • Gardenology.org
adding this content, using forms or autocompletion, or • Math Images Project
more complex proposal generation or consistency • Metavid
checks. The representation language may be wiki syntax, • NeuroLex
a standard language like RDF or OWL, or some database • OpenEI
directly populated by the tool that withdraws the seman- • SKYbrary
tics from the raw data. Separate versioning support or • SNPedia
correction editing for the formalized content may also
be provided. Provenance support for the formalized con-
tent, that is, tagging the author of the data separately
References
from the data itself, varies. [1] Semantic Wikis and Disaster Relief Operations,
What data can get formalized also varies. One may Soenke Ziesche, xml.com, December 13, 2006
be able to specify types for pages, categories or para- [2] Semantic Wikis: A Comprehensible Introduction
graphs or sentences (the latter features were more com- with Examples from the Health Sciences, Maged N.
mon in pre-web systems). Links are usually also typed. Kamel Boulos, Journal of Emerging Technologies in
The source, property and target may be determined by Web Intelligence, Vol. 1, No. 1, August 2009
some defaults, e.g. in Semantic MediaWiki the source is [3] Andy Dingley (21 January 2001). "Wikiwiki (was
always the current page. Theory: "opportunistic hypertext")".
Reflexivity also varies. More reflexive user interfaces comp.infosystems.www.authoring.site-design.
provide strong ontology support from within the wiki, (Web link).
and allow it to be loaded, saved, created and changed. [4] Leo Sauermann (2003) (pdf). The Gnowsis-Using
Some wikis inherit their ontology entirely from a pre- Semantic Web Technologies to build a Semantic Desktop.
existing strong ontology like Cyc or SKOS, while, on the Technical University of Vienna.
other extreme, in other semantic wikis the entire ontol- http://www.dfki.uni-kl.de/~sauermann/papers/
ogy is generated by users. sauermann2003.pdf. Retrieved 2007-06-20.
Conventional, non-semantic wikis typically still have [5] Call for Papers: SemWiki 2006
ways for users to express data and metadata, typically by [6] Wikia offers Semantic MediaWiki hosting, semantic-
tagging, categorizing and using namespaces. In semantic mediawiki.org, March 12, 2008
wikis, these features still typically exist, but integrated [7] Deeper understanding with Metaweb, Official
these with other semantic declarations, and sometimes Google Blog, July 16, 2010
with their use restricted.
Some semantic wikis provide reasoning support, us-
ing a variety of engines. Such reasoning may require that
External links
all instance data comply with the ontologies. • Semantic wiki article at SemanticWeb.org
Most semantic wikis have simple querying support • Semantic wiki projects - contains a list of active,
(such as searching for all triples with a certain subject, defunct and proposed semantic wiki applications
predicate, object), but the degree of advanced query sup- • SemWiki.org – homepage of the semantic wiki
port varies; some semantic wikis provide querying in community and workshop series
standard languages like SPARQL, while others instead • SemanticWiki mini-series - homepage of the virtual
provide a custom language. User interface support to mini-series jointly organized by FZI Karlsruhe, Mayo
construct these also varies. Visualization of the links es- Clinic, Ontolog, RPI Tetherless World Constellation
pecially may be supported. and Salzburg Research, Austria between Sep-2008
Many semantic wikis can display the relationships and Mar-2009.
between pages, or other data such as dates, geographical
2
From Wikipedia, the free encyclopedia Semantic wiki
Retrieved from "http://en.wikipedia.org/w/index.php?title=Semantic_wiki&oldid=466015018"
Categories:
• Semantic wikis
• Semantic wiki software
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