(Part of our DBpedia+spotlight @ GSoC mini blog series)
Mentor: Marco Fossati @hjfocs <fossati[at]spaziodati.eu>
Student: Kasun Perera <kkasunperera[at]gmail.com>
The latest version of the DBpedia ontology has 529 classes. It is not well balanced and shows a lack of coverage in terms of encyclopedic knowledge representation.
Furthermore, the current typing approach involves a costly manual mapping effort and heavily depends on the presence of infoboxes in Wikipedia articles.
Hence, a large number of DBpedia instances is either un-typed, due to a missing mapping or a missing infobox, or has a too generic or too specialized type, due to the nature of the ontology.
The goal of this project is to identify a set of senseful Wikipedia categories that can be used to extend the coverage of DBpedia instances.
How we used the Wikipedia category system
Wikipedia categories are organized in some kind of really messy hierarchy, which is of little use from an ontological point of view.
We investigated how to process this chaotic world.
Here’s what we have done
We have identified a set of meaningful categories by combining the following approaches:
Algorithmic, programmatically traversing the whole Wikipedia category system.
Linguistic, identifying conceptual categories with NLP techniques.
We got inspired by the YAGO guys.
Multilingual, leveraging interlanguage links.
Kudos to Aleksander Pohl for the idea.
Post-mortem, cleaning out stuff that was still not relevant
No resurrection without Freebase!
We found out a total amount of 3751 candidates that can be used to type the instances.
We produced a dataset in the following format:
<Wikipedia_article_page> rdf:type <article_category>
You can access the full dump here. This has not been validated by humans yet.
If you feel like having a look at it, please tell us what do you think about.
Take a look at the Kasun’s progress page for more details.