Institute for Web Science and Technologies · Universität Koblenz
Institute WeST
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Forschungspraktikum Open Knowledge Bases

[zur Übersicht]

Sommersemester 2016

Are you interested in Free Knowledge? Do you like data management? This summer term you will have the opportunity to learn about Open Knowledge Bases and work with Wikidata, one of the latest projects of Wikimedia, the organisation that manages Wikipedia.


Wikidata is a free and collaborative knowledge base created and maintained by volunteers. Wikidata represents human knowledge, but in contrast to Wikipedia, it contains structured data. Wikidata describes world entities (e.g. locations, persons, events, books, etc.) via statements that contain claims (e.g. “Koblenz has sister city Maastricht”) and references to external information sources that support the claims.

As an example, you can see the Wikidata item for Koblenz here:

Wikidata can be used by any system and it is becoming the database for Wikipedia. Wikidata’s centralized and multilingual data management can make Wikipedia articles improve their consistency and information coverage across different languages. For example, if the Infoboxes of the articles for Koblenz in the different Wikipedias (e.g. English, German, Spanish) point to the Wikidata item for Koblenz, when one updates the population of Koblenz in Wikidata, that number will be simultaneously updated in all Wikipedia articles and will save a lot of work to editors who would not need to edit each of the different language Wikipedia articles. See this presentation by Krötzsch for further motivational examples of Wikidata.  

One of the particularities of Wikidata is that it allows to represent knowledge from different points of view, as Pintscher pointed out : a Wikidata item may have statements with multiple values. Wikidata can specify that an item (e.g. Berlin) has a particular value (e.g. 3,000,000 inhabitants) for a property (e.g. population), according to a particular source of information (e.g. the statistics office of Berlin); while a different source specifies that the item has a different value for the same property (e.g. 3,500,000 inhabitants). Moreover, multiple values of statements may be ranked.

Goal of the research lab

The aim of this research lab is to work on methods and applications that deal with multi-provenance knowledge in Wikidata. We will work with a use case scenario around news and events. On the one hand, we will work on a tool for gathering multi-view facts about events and encourage their curation in Wikidata. On the other hand, we will define and analyze methods to semi-automatically rank the collected multi-view facts according to Wikidata guidelines.

Team Work

We will organize the Projektpraktikum together with the Forschungspraktikum. Bachelor students will focus on software engineering tasks, while master students will work on research-oriented tasks. Students will work in teams and they are encouraged to use agile methodologies (e.g. Scrum) and collaborative software development technology (e.g. GitHub).

Introductory Meeting

We will have an initial meeting to describe the goals and the methodology of the course in detail.


  • Open Knowledge Bases

  • Goals and Administrative Issues of the Course

  • Technical Introduction to Wikidata


11.04.2016 at 10:00 CET


Building C- Room 208


IMPORTANT: Registration is now closed.

Students interested in attending the Projektpraktikum and Forschungspraktikum are invited to come to the introductory meeting.

In order to make the organization of the meeting easier, if you are interested and you plan to attend please register before 08.04.2016 via this form:


Cristina Sarasua <>


Thu 14.04 at 12:00 E-428


Date Title Link
11.04.2016  Introductory Meeting  OKB_intro_11.04.2016.pdf
14.04.2016  Kick-Off Meeting OKB_kickoff_14042016.pdf
28.04.2016  Regular meeting OKB_28042016.pdf
12.05.2016  Regular meeting OKB_12052016.pdf
12.05 2016  Regular meeting OKB_19052016.pdf
19.05.2016  Regular meeting OKB_19052016.pdf
26.05.2016  Skype meeting OKB_26052016_Skype.pdf
02.06.2016  Regular meeting OKB_02062016.pdf
09.06.2016  Regular meeting  No slides to be uploaded for this session.
16.06.2016  Regular meeting  No slides to be uploaded for this session.
23.06.2016  Regular meeting  No slides to be uploaded for this session.
07.07.2016  Regular meeting OKB_07072016.pdf
14.07.2016  Regular meeting OKB_14072016.pdf

Wikidata Links

Wikidata Wiki:

Wikidata Documentation:

Wikidata Data Access:

Wikidata API:

Wikibase Data Model:

Wikidata Classes and Properties:

Wikidata - All Properties:

Wikidata RDF Data Model:


Bibliographic References

Krötzsch, M., Vrandečić, D., & Völkel, M. (2006). Semantic Mediawiki. In: The Semantic Web-ISWC 2006 (pp. 935-942). Springer Berlin Heidelberg. URL:  

Denny Vrandečić and Markus Krötzsch. 2014. Wikidata: a free collaborative knowledgebase.Commun. ACM 57, 10 (September 2014), 78-85. DOI="" URL:

Erxleben, F., Günther, M., Krötzsch, M., Mendez, J., & Vrandečić, D. (2014). Introducing Wikidata to the linked data web. In The Semantic Web–ISWC 2014 (pp. 50-65). Springer International Publishing. URL:

Müller-Birn, C., Karran, B., Lehmann, J., & Luczak-Rösch, M. (2015, August). Peer-production system or collaborative ontology engineering effort: What is Wikidata?. In Proceedings of the 11th International Symposium on Open Collaboration (p. 20). ACM. URL: