Knowledge graphs

Acquiring access for our consumers to a semantic network of relevant linked open data compiled by other efforts and structured by a number of ontologies is obviously key to Consumerium. Reciprocally we aim to share the information we gather and compile available to other efforts.

See also: mw:Manual:Managing data in MediaWiki at


The Wikidata logo

Wikidata (.org) is a knowledge base, an effort to store and serve structured data to Wikimedia wikis and to a more limited extent to other parties. Wikidata effort saw the daylight in 2012.

The underlying software is the Wikibase which consists of 2 Mediawiki extensions, the Wikibase Repository and the Wikibase Client.

Wikibase allows interwiki links to be managed with Wikidata removing much contributor annoyanges, redundancy and error-proneness.

Wikidata is obviously a very viable source of reference level data once it is technically possible for non-WMF wikis to access the data items. (See #LinkedWiki extension for a potential workaround for this limitation)

It can be accessed outside of WMF wikis with with

Main entry point of any Wikidata item is a JSON dictionary, that has this form:

{“labels”: by-language dictionary

“descriptions”: by-language dictionary

“aliases”: by-language dictionary

“claims”: list of property and values

“sitelinks”: by-language dictionary}

Lexicographical WikidataEdit

A lexeme is a unit of lexical meaning that underlies a set of words that are related through inflection. It is a basic abstract unit of meaning,[1] a unit of morphological analysis in w:linguistics that roughly corresponds to a set of forms taken by a single root w:word. For example, in English, run, runs, ran and running are forms of the same lexeme, which can be represented as RUN (Wikipedia on 2019-12-29)

Since 2018, Wikidata has also stored a new type of data: words, phrases and sentences, in many languages, described in many languages. This information is stored in new types of entities, called Lexemes (L), Forms (F) and Senses (S).[2]. This is enabled by the WikibaseLexeme extension.

Useful informationEdit

More info


The Wikibase logo

Wikibase ( is a system for storing and querying structured data that powers Wikidata and other wikis.

Wikibase consists of two extensions:

  1. Wikibase Repository that allows a wiki to work as a repository for structured data.
  2. Wikibase Client that allows a wiki to access structured data from a repository. The client can work only with repository databases it can access so they must be on the same machine or the same load balancer.

Installation of WikibaseEdit

Wikibase installation instructions at and advanced configuration of Wikibase.

The installation instructions assume you are installing the dependencies with Composer, a PHP package manager that makes the installation of dependencies easy.

Useful extensions in conjunction with WikibaseEdit

Alternative to using Wikibase ClientEdit

Useful informationEdit

Semantic MediaWikiEdit

Semantic MediaWiki (.org) (SMW) is a free, open-source extension to MediaWiki that lets you store & query semantic data within the wiki and it seems well suited to Consumerium's information infrastructure needs.

Spinoff extensionsEdit

A variety of open-source MediaWiki extensions exist that use the data structure provided by Semantic MediaWiki.

Among the most notable are of the Semantic MediaWiki extensions:

  • Semantic Forms - enables user-created forms for adding and editing pages that use semantic data
  • Semantic Result Formats - provides a large number of display formats for semantic data, including charts, graphs, calendars and mathematical functions
  • Semantic Drilldown - provides a w:faceted browser interface for viewing the semantic data in a wiki
  • Semantic Maps - displays geographic semantic data using various mapping services

Open Food FactsEdit

Open Food Facts logo 2022

Open Food Facts (.org) is a crowdsourced non-profit open database, web app and mobile apps of food products initiated in 2012 by French programmer Stéphane Gigandet. It is limited to foodstuffs only by the contract, others will be removed and clearly seeks not to be political.

The database is copylefted under w:Open Database License, database entries under Database Contents License and the uploaded photos under CC-BY-3.0 Creative Commons so the database and the photos can be reused in other services so it would seem a good place to contribute as open data is available in various formats.

w:Nutri-score is a nutritional grading system adopted by the French government in 2017. This is one type of information found in the Open Food Facts database because it is on the label. Nutri-score can be approximately calculated for also for products that do not have it on the packaging.

Information verification is based on photos of the labeling on the package. Adding information not featured on the label seems to be forbidden, probably to avoid legal problems arising.

In Wikipedia


Sites by OFF

Interesting wiki articles

Sites reusing OFF data set

Spinoffs / expansions of scope


The DBpedia logo

DBpedia (.org) is a community effort to enable the web moving "Towards a Public Data Infrastructure for a Large, Multilingual, Semantic Knowledge Graph".

Today the DBpedia data sets contain a wealth of information structured into ontologies. This structured data can be queried with SPARQL query language at their public DBpedia SPARQL endpoint.

DBpedia uses w:Virtuoso Universal Server to store and query the data. VirtuosoUniversalServer at

There are many methods how the DBpedia ontology and datasets could be used in the Consumerium implementation stage wiki.

Ontology classes useful for implementing ConsumeriumEdit

All DBpedia ontology classes

DBpedia datasetsEdit

DBpedia DatabusEdit

The DBpedia Databus at is a data cataloging and versioning platform for data developers and consumers.

SPARQL endpoint at

DBpedia developed the DBpedia Databus in the late 2010's with a Databus alpha published in May 2018.

History of DBpediaEdit

DBpedia began as an effort to extract structured information from Wikipedia infobox templates and categories and to make this information available on the Web with the initial release on January 10th 2007.

More info on DBpediaEdit

LinkedWiki extensionEdit

A possible way to tap into various knowledge graphs is the LinkedWiki extension. LinkedWiki has been developed since 2010 by mw:User:Karima Rafes, a #Semantic MediaWiki developer and CEO of

See also


  1. The Cambridge Encyclopedia of The English Language. Ed. [[w:David Crystal|]]. Cambridge: Cambridge University Press, 1995. p. 118. Template:ISBN.
  2. wikibooks:SPARQL/WIKIDATA Lexicographical data