Re: [Wikidata-l] Wikidata RDF exports

properties), so you can find "all subclasses" there too. (You could also try this in Protege ...)

too or just labels?

Eric, Two general remarks first: (1) Protege is for small and medium ontologies, but not really for such large datasets. To get SPARQL support for the whole data, you could to install Virtuoso. It also comes with a simple Web query UI. Virtuoso does not do much reasoning, but you can use SPARQL 1.1 transitive closure in queries (using "*" after properties), so you can find "all subclasses" there too. (You could also try this in Protege ...) (2) If you want to explore the class hierarchy, you can also try our new class browser: http://tools.wmflabs.org/wikidata-exports/miga/?classes It has the whole class hierarchy, but without the "leaves" (=instances of classes + subclasses that have no own subclasses/instances). For example, it tells you that "lepton" has 5 direct subclasses, but shows only one: http://tools.wmflabs.org/wikidata-exports/miga/?classes#_item=3338 On the other hand, it includes relationships of classes and properties that are not part of the RDF (we extract this from the data by considering co-occurrence). Example: "Classes that have no superclasses but at least 10 instances, and which are often used with the property 'sex or gender'": http://tools.wmflabs.org/wikidata-exports/miga/? classes#_cat=Classes/Direct%20superclasses=__null/Number% 20of%20direct%20instances=10%20-%2020000/Related% 20properties=sex%20or%20gender I already added superclasses for some of those in Wikidata now -- data in the browser is updated with some delay based on dump files. More answers below: On 14/06/14 05:52, emw wrote: You need a reasoner to compute this properly. For a plain class hierarchy as in our case, ELK should be a good choice [1]. You can install the ELK Protege plugin and use it to classify the ontology [2]. Protege will then show the copmuted class hierarchy in the browser; I am not sure what happens to the SPARQL queries (it's quite possible that they don't use the reasoner). [1] https://code.google.com/p/elk-reasoner/ [2] https://code.google.com/p/elk-reasoner/wiki/ElkProtege We had not thought of this as a use case. A challenge is that the label data is quite big because of the many languages. Should we maybe create an English label file for the classes? Descriptions too or just labels? What kind of "pruning" do you have in mind? You can of course take a subset of the data, but then some of the data will be missing. A general remark on mixing and matching RDF files. We use N3 format, where every line in the ontology is self-contained (no multi-line constructs, no header, no namespaces). Therefore, any subset of the lines of any of our files is still a valid file. So if you want to have only a slice of the data (maybe to experiment with), then you could simply do something like: gunzip -c wikidata-statements.nt.gz | head -10000 > partial-data.nt "head" simply selects the first 10000 lines here. You could also use grep to select specific triples instead, such as: zgrep "http://www.w3.org/2000/01/rdf-schema#label" wikidata-terms.nt.gz | grep "@en ." > en-labels.nt This selects all English labels. I am using zgrep here for a change; you can also use gunzip as above. Similar methods can also be used to count things in the ontology (use grep -c to count lines = triples). Finally, you can combine multiple files into one by simply concatenating them in any order: cat partial-data-1.nt > mydata.nt cat partial-data-2.nt >> mydata.nt ... Maybe you can experiment a bit and let us know if there is any export that would be particularly meaningful for you. Cheers, Markus _______________________________________________ Wikidata-l mailing list Wikidata-l(a)lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikidata-l