| The Wikidata taxonomy is basically the successor to Wikipedia's category tree. It not only irons out language-based differences (e.g. the category tree being different among Chinese, Spanish, English, etc. Wikipedias), but also captures the idea of generalization through a more semantically meaningful relation. This Wikidata concept tree is constructed with "subclass of" (P279) [1], a property that expresses the proposition "all instances of these items are also instances of those items". The goal is to have a subsumption hierarchy that classifies all human knowledge. There's an RDF/OWL export of the Wikidata taxonomy available at [2] as wikidata-taxonomy.nt.gz, which can be explored with Semantic Web browsers like Protege [3]. Another fundamental relation -- "part of" (P361) [4] -- expresses mereological relationships. For (oversimplified) example: "iris part of eye", "eye part of head", "head part of body", etc. Both "subclass of" and "part of" are transitive. A separate comment of mine in this discussion [5] describes how to traverse the "subclass of" tree in the Wikidata UI and a third-party tool called Wikidata Generic Tree. The same principle applies to the "part of" tree. The latter gets less attention, but is also quite interesting. --- 1. https://www.wikidata.org/wiki/Property:P279 2. http://tools.wmflabs.org/wikidata-exports/rdf/index.php?cont... 3. http://protege.stanford.edu/ 4. https://www.wikidata.org/wiki/Property:P361 5. https://news.ycombinator.com/item?id=10448573 |
I am very excited about the potential knowledge engineering possibilities opened up by this large structured datasets.
I believe that at the very least we're going to have within a generation a machine-generated ontology to rival Kant and Aristotle. Then we'll have to figure out if this tells us more about how we've digitally organized the knowledge we have or whether it does in fact reveal something about reality and being.
Besides 'subclass of' and 'part of' are there any other taxonomic ways for concepts to relate to other concepts? There are parallels here of course with object-oriented-programming. It's funny, I only within the last year or so started reading up on mereology[0] but as soon as one starts thinking about concepts and there relationships one ends up there eventually. 'part of' is like encapsulation. 'subclass of' is like inheritance. Is there more?
[0] (from the Greek μερος, ‘part’) http://plato.stanford.edu/entries/mereology/