Databases Reference
In-Depth Information
Ta b l e 2 .
Conceptual di
ff
erences between Semantic MediaWiki and OntoWiki
Semantic MediaWiki
OntoWiki
Managed entities
Articles
Resources
Editing
Wiki markup
Forms
Atomic element
Text blob
Statement
Extending Wikis with Semantic Markup.
The benefit of a Wiki system comes from
the amount of interlinking between Wiki pages. Those links clearly state a relationship
between the linked-to and the linking page. However, in conventional Wiki systems this
relationship cannot be made explicit. Semantic Wiki systems therefore add a means to
specify typed relations by extending the Wiki markup with semantic (i.e. typed) links.
Once in place, those links form a knowledge base underlying the Wiki which can be
used to improve search, browsing or automatically generated lists and category pages.
Examples of approaches for extending Wikis with semantic markup can be found in
[77,138,14,122,143]. They represent a straightforward combination of existing Wiki
systems and the Semantic Web knowledge representation paradigms.Yet,weseethe
following obstacles:
Usability
:
The main advantage of Wiki systems is their unbeatable usability. Adding
more and more syntactic possibilities counteracts ease of use for editors.
Redundancy
:
To allow the answering of real-time queries to the knowledge base, state-
ments have to be additionally kept in a triple store. This introduces a redundancy,
which complicates the implementation.
Evolution
:
As a result of storing information in both Wiki texts and triple store, sup-
porting evolution of knowledge is di
cult.
Wikis for Editing Structured Data.
In contrast to text-based systems, Wikis for struc-
tured data - also called Data Wikis - are built on a structured model of the data being
edited. The Wiki software can be used to add instances according to the schema or (in
some systems) edit the schema itself. One of those systems is OntoWiki
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[9] which
bases its data model on RDF. This way, both schema and instance data are represented
using the same low-level model (i.e. statements) and can therefore be handled identi-
cally by the Wiki.
4.1
OntoWiki - A Semantic Data Wiki
OntoWiki started as an RDF-based data wiki with emphasis on collaboration but has
meanwhile evolved into a comprehensive framework for developing Semantic Web ap-
plications [55]. This involved not only the development of a sophisticated extension
interface allowing for a wide range of customizations but also the addition of several ac-
cess and consumption interfaces allowing OntoWiki installations to play both a provider
and a consumer role in the emerging Web of Data.
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Available at:
http://ontowiki.net
