http://wiki.dbpedia.org/Datasets#h18-11
Wikipedia infoboxes contain very specific information about things and are
thus a very valuable source of structured information that can be used
to ask expressive queries against Wikipedia. The DBpedia project currently
extracts three different datasets from the Wikipedia infoboxes.
1. The *Infobox Dataset* is created using our initial, now three year
old infobox parsing approach. This extractor extracts all properties from
all infoboxes and templates within all Wikipedia articles. Extracted
information is represented using properties in the
http://dbpedia.org/property/ namespace. The names of the these
properties directly reflect the name of the Wikipedia infobox property.
Property names are not cleaned or merged. Property types are not part of a
subsumption hierarchy and there is no consistent ontology for the infobox
dataset. Currently, there are approximately 8000 different property types.
The infobox extractor performs only a minimal amount of property value
clean-up, e.g., by converting a value like “June 2009” to the XML Schema
format “2009–06”. You should therefore use the infobox dataset only
if your application requires complete coverage of all Wikipeda properties
and you are prepared to accept relatively noisy data.
2. The *Infobox Ontology*. With the DBpedia 3.2 release, we introduced
a new infobox extraction method which is based on hand-generated mappings
of Wikipedia infoboxes/templates to a newly created DBpedia
ontology<http://wiki.dbpedia.org/Ontology>.
The mappings adjust weaknesses in the Wikipedia infobox system, like using
different infoboxes for the same type of thing (class) or using different
property names for the same property. Therefore, the instance data within
the infobox ontology is much cleaner and better structured than the Infobox
Dataset, but currently doesn't cover all infobox types and infobox
properties within Wikipedia. Starting with DBpedia release 3.5, we provide
three different Infobox Ontology data sets:
- The *Ontology Infobox Types* dataset contains the rdf:types of the
instances which have been extracted from the infoboxes.
- The *Ontology Infobox Properties* dataset contains the actual data
values that have been extracted from infoboxes. The data values
are represented using ontology properties (e.g., 'volume') that
may be applied to different things (e.g., the volume of a lake and the
volume of a planet). This restricts the number of different
properties to a
minimum, but has the drawback that it is not possible to automatically
infer the class of an entity based on a property. For instance,
an application that discovers an entity described using the
volume property
cannot infer that that the entity is a lake and then for example
use a map
to visualize the entity. Properties are represented using properties
following the http://dbpedia.org/ontology/{propertyname} naming
schema. All values are normalized to their respective SI unit.
- The *Ontology Infobox Properties (Specific)* dataset contains
properties which have been specialized for a specific class using
a specific unit. e.g. the property height is specialized on the class
Person using the unit centimetres instead of metres. Specialized
properties
follow the http://dbpedia.org/ontology/{Class}/{property} naming
schema (e.g.http://dbpedia.org/ontology/Person/height).
The properties have a single class as rdfs:domain and rdfs:range and can
therefore be used for classification reasoning. This makes it easier
to express queries against the data, e.g., finding all lakes whose volume
is in a certain range. Typically, the range of the properties
are not using
SI units, but a unit which is more appropriate in the specific domain.
All three data sets are available for
download<http://wiki.dbpedia.org/Downloads> as well
as being available for queries via the DBpedia SPARQL endpoint.
See also
http://wiki.dbpedia.org/Downloads38#ontology-infobox-properties
http://wiki.dbpedia.org/Downloads38#raw-infobox-properties
On 12 July 2013 12:06, Basil Ell <[email protected]> wrote:
> Hi,
>
> I was wondering if there is some dataset that contains
> owl:equivalentProperty triples for dbpedia properties.
>
> For example, I believe that the following properties are equivalent:
>
> <http://dbpedia.org/ontology/subsidiary><http://dbpedia.org/ontology/subsidiary>
>
> <http://dbpedia.org/property/subsidiary><http://dbpedia.org/property/subsidiary>
> <http://dbpedia.org/property/subsid><http://dbpedia.org/property/subsid>
>
> However, this information cannot be found in dbpedia.
>
> According to
> SELECT COUNT DISTINCT * WHERE {
> ?s owl:equivalentProperty ?o .
> }
> there are only 31 equivalencies.
>
> When querying the LOD cloud cache at http://lod.openlinksw.com/sparql,
> according to
> SELECT count distinct ?s WHERE {
> ?s owl:equivalentProperty ?o .
> FILTER(regex(?s, "dbpedia"))
> }
> there are 31 triples
> and according to
> SELECT count distinct ?s WHERE {
> ?s owl:equivalentProperty ?o .
> FILTER(regex(?o, "dbpedia"))
> }
> there are 87 triples.
>
> From the mappings wiki (http://mappings.dbpedia.org/) I could extract
> only 49 equivalencies.
>
> These numbers are rather small. Am I missing something, is there a data
> set containing these equivalencies somewhere?
>
> Best regards and thanks for any insights,
> Basil
>
>
>
>
>
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