Proposal for the integration of the semantic structure of Wikipedia categories into Wikidata using SKOS
DBpedia is the most prominent dataset in Linked Open Data ecosystem. Wikidata is a Wikimedia movement initiative to represent knowledge as data, structured, defined and maintained collaboratively. Both are cross domain Open Knowledge Graphs. WikiData is intended to change the way in which data is used by the Wikimedia editors, and it will probably have influence in how DBpedia data is collected. So, improving the semantic of Wikipedia Categories in Wikidata will have a deep impact in Knowledge Organization. In this work we propose a methodology for the SKOS integration into de WikiData data model of the Wikipedia Category semantic structure. An analytic comparative report of how Wikipedia categories are treated in DBpedia and WikiData is conducted, including not only the terms itself, but also their relationships and correspondences. Equivalence patterns between the objects or entities of the three sources Wikipedia, DBpedia and Wikidata are identified. Other content elements, such as articles, participation records or external links are also take in consideration. Then, keeping in mind the autodescriptive nature of WikiData infrastructure a set of entities and properties that allow the use of SKOS to represent semantic relationships are suggested. Last, we have designed and tested a methodology for the automatic design of an automatic process of reuse of semantic representation of semantic relations in Dbpedia. The proposal details the SKOS properties and classes that should be included as WikiData entities, in order to represent categories semantic relationships and its mappings and cross references with other SKOS datasets. Technical advice of how obtain and adapt DBpedia categories RDF statements in order to be incorporated in WikiData is exposed. This methodology, whose results are a kind of alignment between DBpedia and WikiData categories, is built upon the matching between their different representations. A bunch of tasks, procedures and tools are developed, that allow manage not only concepts, but also SKOS labels and semantic relationships existing in Dbpedia. Adding semantic relationships of Wikipedia categories in Wikidata is viable, and DBpedia is a worthy tool for do this. Including semantic relationships in Wikidata improve its quality as a Knowledge Organization resource. Wikidata categories, whose source is Wikipedia, may be used as an element to align thesauri, subject headings, taxonomies, etc. Due this reason, apply SKOS in category representation could be the first step for Wikidata not only to be a factual database, but also a knowledge organization platform.