Semantic MediaWiki as Knowledge Graph Interface

www.kdz.or.at
Semantic MediaWiki as
Knowledge Graph interface
May 5, 2021
Bernhard Krabina
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Introduction: Bernhard Krabina
 researcher, consulter, trainer at KDZ – Centre for
Public Administration Research
 www.kdz.eu
 active member of the Semantic MediaWiki
community
 www.semantic-mediawiki.org
 PhD candidate at Vienna University of Economics
and Business, Institute for Data, Process and
Knowledge Management
 www.wu.ac.at/en/dpkm
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Agenda
What is SMW?
What makes it a Knowledge
Graph tool?
How to use it as KG interface?

What is Semantic MediaWiki (SMW)?
 open source project:
 www.semantic-mediawiki.org
 https://github.com/SemanticMediaWiki
 the „swiss army knife“ for data and semantics
 built on the MediaWiki ecosystem:
the wiki engine that powers Wikipedia
can be used for much more than just wikis… 4

Knowledge Graphs and Wikipedia vs. custom KG
 extract structured information from Wikipedia and
make this information available on the Web
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 free knowledge base that can be read and edited by
humans and machines alike… central storage for the
data that may be accessed by the client Wikipedias
 turns MediaWiki into a powerful and flexible
knowledge management system
 lets you store and query data within the wiki's pages
 a set of extensions for MediaWiki

MediaWiki + SMW + more extensions
 collaborative editing
 version history of every
edit
 no backend:
everything is a wiki page
 structure via categories
and namespaces
 API
 structured data
(Web database)
 result lists and formats
via {{#ask:}} queries
 Semantic Web
standards
 triplestore support
 …
 online forms for data
entry
 more visualizations
 responsive skin
 authentication
 image annotation
 SPARQL
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Semantic MediaWiki as Knowledge Graph tool
KG Definition (Sack/Alam 2020) Semantic MediaWiki
concepts Concept:
classes Category: rdf:type
properties Property: with datatypes
relationships annotations via wikitext or templates
entity descriptions wiki pages
RDF(S)/OWL / (OWL 2 DL)
open/private/closed //
original/derived/agregated //
instance data wiki pages or subobjects (instances without wiki
pages)
schema data Help:Schema
metadata via special semantic properties
Taxonomies subcategories rdfs:subClassOf
links and mappings to external data datatype „External identifier“, vocabulary import 8

Building your Knowledge Graph
 page Vienna can have properties
 number of inhabitants, located in,
coordinates, WikidataID, …
 properties can have various data types
 page, text, number, date, URL, …
 external identifier links to external resources
 re-use external vocabularies
 “Lastname” imported from foaf:familyName
 a page should be put into a category
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optional
 setup templates
 setup forms
 do internal
querying
 use built in search
interfaces

FINA Wiki:
https://fina.oeaw.ac.at/wiki
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Map
(birth,
death place)
Literature
Work
References
Visualisation of
correspondence
Structured data
Iconography
Export (CSV, RDF)

Internal query language
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{{#ask:
[[Category:Topographic Object]]
[[Named after::Sigmund Freud]]
|mainlabel=Objekt
|?District
|?Coordinates
|format=table
}}

Internal query language
{{#ask:
[[Category:Topographic Object]]
[[Named after::Sigmund Freud]]
|mainlabel=Objekt
|?District
|?Coordinates
|format=map
}}
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Semantic MediaWiki storage options
 SQL Store (default)
 extra tables in
the SQL store of
MediaWiki
 ElasticStore
 search engine, not
a storage backend
 data storage and
management
remains part of the
SQLStore
 SPARQL/RDF Store
 custom, default
 Virtuoso
 Blazegraph
 Fuseki
 Sesame
 4store
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easy (to install) harder to install but more powerful

SPARQL
 Internal querying
{{#ask: …}}
RDF dump can be imported in
triplestores, or direct connection:
 Other approaches via extensions
 LinkedWiki: SPARQL queries of
internal/external data in the wiki
 SPARQLResultFormat: query
external data
 RDFIO: PHP-based SPARQL
endpoint
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Maintaining your Knowledge Graph
Data/ontology curation: “semantic gardening”
 user rights
 admins, curators, users
 property annotation health
 Outdated properties/entities
 Similar properties
 Property uniqueness
 Improper annotations and failed queries
 Missing redirect annotations
https://www.semantic-
mediawiki.org/wiki/Semantic_gardening
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Inferencing
 subcategories
 subproperties
 equality of pages:
redirects
 subqueries
https://www.semantic-
mediawiki.org/wiki/Help:Inferencing

Semantic MediaWiki or Wikibase?
https://www.mediawiki.org/wiki/Manual:Managing_data_in_MediaWiki
Semantic MediaWiki Wikibase
flexible data model data model of Wikidata
properties can be pre-defined or declared by
annotating
properties need to be pre-defined
requires extensions for form-based input comes with a fixed, built-in edit interface
SPARQL only with external triplestore
internal query language (easier than SPARQL) no built-in querying of data
enterprise-ready (stability, commercial support)
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@KGConference
linkedin.com/company/the-knowldge-graph-conference/
youtube.com/playlist?list=PLAiy7NYe9U2Gjg-600CTV1HGypiF95d_D
#KGC2021
#SemanticMW
Join the Conversation
@krabina
linkedin.com/in/krabina

Semantic MediaWiki as Knowledge Graph Interface

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